Staff writers at Sonic Electronix are experts in their field. In addition to a complete in-house training program, these experts typically have many years of hands-on experience in their specialty. Some come from car audio installer backgrounds, while others come with extensive retail experience.
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Understanding Tweeter Design and Construction

Understanding Tweeters

Dome Style TweeterThere are many considerations when upgrading the audio system in a car, and one of the most overlooked aspects is the tweeter. The way a tweeter is shaped and the material with which it is constructed plays a large role in how the music will sound. The tweeter is the part of the speaker that reproduces the high-frequency sounds in music, namely the guitars, vocals and horns. Tweeters also help to give audio more body, so the sounds are not trapped near floor level, where they can be difficult to hear and enjoy.

Several factors are considered in the choice of a tweeter for any particular speaker, namely cost and the quality of sound that is produced. The challenge lies in keeping the tweeter lightweight without compromising its ability to hold up under high-volume conditions. A tweeter also needs to have good damping, which means it quits vibrating quickly when the music stops playing. To achieve these goals, tweeters can have varying shapes and be made from different materials, the details of which are explained below.

Shapes of Tweeters

  • A tweeter’s shape determines the efficiency of high-frequency response. A variety of shapes are used to obtain the best results when compared to cost.Dome Style Tweeter
  • The cone type tweeter is the cheapest to manufacture and is the design found most often in car audio systems. Most standard tweeters of this type are “whizzers”, which are tweeters that are placed inside the woofers to maximize high-frequency response. The drawbacks of this type include an inefficiency to properly distribute sound, and poor overall audio quality.
  • The semi-dome type tweeter, also known as a balanced-type, is a cone-shaped tweeter with a dome built inside of it. Both parts are about the same size and are found in lower-end speakers. The materials used for this type of tweeter are softer and provide a lower profile, which limits damage through improper mounting or poor handling. This tweeter type is found mostly in coaxial speakers, although it is also seen rarely in component speakers as well.
  • A dome tweeter offers the best dispersion of high-frequency sound and a wider range with which to work when setting the system up. The details of the speaker will include the dome’s size. Larger dome tweeters require higher levels of power to operate properly and deliver the best results.

Tweeter Materials

The materials used in the construction of tweeters can include aluminum, silk, titanium and beryllium. The majority of materials fall into three basic categories.

  • Synthetic films are light in weight and tolerant to humidity, which is a must in a car interior. They require minimal power to operate and are often found in low-cost audio system speakers. Unfortunately, tweeters made from films have limited damping capabilities and do not produce high-quality sound output.
  • Silk is a textile material used in tweeter construction. It offers the advantage of a more refined, lifelike sound result and is often used in home audio systems. High-power silk tweeters are reinforced with other synthetics to provide superior damping results, allowing for high volume, accuracy and smoothness.
  • Tweeters built with blended metals output loud and crisp high-frequency sound. Aluminum is most commonly used for this purpose, as it will produce highs that can be distinguished from bass and noise from the road. Another approach is titanium, which is extremely lightweight and produces very accurate highs without the roughness that can occur with aluminum tweeters. It is expected that manufacturers will expand into more exotic combinations of metals and ceramics as time goes on.

Making the Right Choice

When it comes down to making a choice between silk and metal, the type of car and driving style makes a difference. For example, if the car is driven mostly with the windows open allowing in a lot of road noise, metal tweeters are the better choice. A quiet auto interior calls for silk tweeters to produce the most natural-sounding audio.

Separates and Coaxials

Tweeters can be separate from the speaker‘s woofer or completely integrated. This can be a crucial difference when placing speakers inside of a car, as the higher the tweeter’s position, the more efficiently it can disperse the sound. It is important to note that a cheap tweeter is not going to provide quality sound output regardless of where it is placed.

Some types of speakers, such as three-way and four-way models, have multiple tweeters, which further separates sonic sound frequencies. In the case of a three-way speaker, there can be a driver for the mid-range, which gives the music a warmer quality, or a supertweeter, which offers superior response in the high-frequency range.

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The Vehicle Lighting Buying Guide

Vehicle Lights

Vehicle Lighting

Lighting is one of the coolest and most functional mods you can do to your vehicle but there are so many choices to choose from! At Sonic Electronix, we carry HID Lights, Daytime Running Lights, Fog Lights, Driving Lights and Accent Lighting. In this Knowledge Base article we’ll break each of these categories down and tell you why you need (or want) each one and what to look for before buying.

Click the links below to view a specific section or scroll through and read it all!

1. HID Headlights

2. Daytime Running Lights

3. Fog Lights

4. Driving Lights

5. Accent Lighting

HID Headlights

HID Headlights

What Are They?

HID’s replace your stock headlights and stand for High Intensity Discharge which basically means “really, really bright lights.” HID’s create this ultra bright light by igniting an electrical discharge between two tungsten electrodes inside a quartz capsule filled with a gas such as Xenon and a metal salt. When an electric current is sent through the electrodes in the bulb the reaction occurs and the metal salts are evaporated forming a plasma, which both intensifies the light, and also reduces the energy consumption of the bulb. Since there is no filament in the bulb like with your normal halogen bulb, this also makes the HID bulb much more durable and longer lasting.

What To Look For When Buying

Color- Color is measured in Kelvins (K). When you see something like a 6000K bulb, the “6000” is letting you know the color of the bulb and NOT the brightness—a common misconception. The lower the Kelvins, the more yellow the light is. 3000K is completely amber, 4300K is a yellow-white. The higher the Kelvins, the whiter and bluer they get. 6000K is pure white, 10,000K is dark blue and 12,000K is a blue-violet color.

Bulb Size- When you see a model number like 9006-6K-G4, the “9006” section lets you know what size the bulb is. 9006 is the most common but make sure you check the owner’s manual for your vehicle to find out what size bulb your car uses; or use our handy bulb finder tool: http://www.philipsautolighting.com/selector.php

Low Beams or High AND Low Beams- Do you want to replace your normal headlights with HID’s, or both your High and Low Beams? Low Beams are the most commonly replaced headlights since they get used far more frequently than high beams. However, if you replace your Low beams only and you use your High beams, you’ll notice your HID Low beam lights are going to provide more visibility than your halogen high beams. You can use our Guided Browsing tool on the left hand side of the HID page to filter out Low Beam or Dual Beam headlights: http://www.sonicelectronix.com/cat_i1204_hid-headlight-kits.html

AC Ballasts- All of the HID series we carry (at the time of this article) have AC Ballasts with the exception of the Vision Extreme Series. DC ballasts do not run as efficiently and run much warmer than AC ballasts. They are perfectly suited for show vehicles and vehicles that do not get driven as much; but if you plan on installing HID’s in your daily driver, spend the extra couple bucks and get yourself a kit with an AC ballast. You’ll thank us later.

CANBUS Compatible- Many newer vehicles use a CANBUS system which is basically a computer system that monitors and controls all the functions in your vehicle such as, but limited to: Air pressure, engine performance, burnt bulbs and sound system functions. Unfortunately, when replacing your headlights with HID’s, CANBUS systems cannot detect the different voltage from the HID’s and will think you have a burned out bulb. The G4 series have built in circuitry that interfaces with your CANBUS system and avoid any issues associated with incompatibility. Take a look at the chart below to see all the benefits the G4 series offers.

Series AC Ballasts Anti-Flickering Capacitors Warning Light Cancellers Radio Interference Protection Circuitry Slim Ballasts Made In The USA Warranty
Vision Extreme 12 Months
Elite 18 Months
Elite Slim 24 Months
G2 24 Months
G4 36 Months
A. G4 KIT Required on 09 and up Dodge Ram, Charger, Challenger, Dart and Chrysler 300. Required to prevent stability control, anti-lock brakes and TPSM from turning off.
B. Vehicles with Bi-Xenon Bulbs (H13/9008, H4/9003/HB2, 9007/HB5, or 9004/HB1) will require both the [[relayres, RELAY-RES]] and one of either the [[hilocanch13,HILOCANC-H13]], [[hilocanch4, HILOCANC-H4]], or [[hilocanc9007, HILOCANC-9007]].
NOTE: Select few vehicles, even with a G4 Kit, may require the [[relayres, RELAY-RES]] This includes, but is not limited to, 2000 and up GM trucks/SUVs. FOR A BULLET PROOF INSTALL WE ALWAYS RECOMMEND A G4 KIT ALONG WITH THE [[relayres, RELAY-RES]] and Hi/Lo canceller if needed.

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Daytime Running Lights

Daytime Running Lights

What Are They?

Daytime running lights, or DRL’s, are lights that are meant to always be on during daytime driving and may be dimmed or turned off at anytime, but usually only at night. These are important because it increases your visibility to other drivers on the road. These lights in some studies have been shown to reduce the rate of accidents on the road by up to 18% by increasing the amount of time a driver has to react to your vehicle during emergencies, and by allowing other drivers to see you more clearly when doing things like merging or turning.

What to Look For When Buying

Style-Manufacturers offer varying styles of DRL’s. You have individual bulbs like on the Racesport Accessories RS-EE-Green, a line style like on the Hella 010043801 and even module chains like the Hella 01045881. Each style will require different installation methods; if you want to do a simple install then a single bulb style is your best bet; if you want something a little brighter and nicer looking, go with the line style; and if you want complete customization then go with the module chain.

Power Consumption- This determines the current draw on your vehicle’s electric system. If you already have a sound system and extra accessories that run if your charging system, you’ll want to use more efficient daytime running lights that won’t be as much of a burden on your battery. The higher end Hella products use as little as 6 watts of power. Of course, you can always upgrade your Big 3 and upgrade your battery and not need to worry about that.

Housing Material- You’ll notice a wide variety of prices when it comes to DRL’s and one of the main factors in that are the materials that are used. Less expensive brands and products use plastic or heavier metals like stamped steel on their housing. Higher end brands use durable and lightweight materials like aluminum and magnesium. Not only are aluminum and magnesium housings lightweight and durable, they dissipate heat much better than steel and plastic, which adds to their longevity.

Lens Material- Just like in the point above, pay attention to the lens materials. Less expensive DRL’s use plastic lens and higher end ones use glass. Plastics can warp and discolor over time and are not as impact resistant as glass which will stay transparent and hold their shape.

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Fog Lights

Fog Lights

What Are They?

Fog lights have a specially designed beam pattern that is specifically meant for rain, snow and fog. Typical headlights (including HID’s) have an unfocused beam pattern because they are meant to cover as much area as possible using a wide spread pattern. This will cause a glare or reflection which will reduce your poor visibility even further in these conditions. Fog lights use a focused beam pattern in order to pierce through the water droplets in the air to prevent that glare and let you see much clearer.

What To Look For Before Buying

Basically, you’ll be looking for the same things as Daytime Running Lights: Power Consumption, Housing and Lens Material. The main thing you want to pay attention to with Fog Lights is their mounting style. Some are meant to mount to the roof of your vehicle on a light rack, some mount in stock fog light locations if your vehicle has them, and some are meant to mount under the front end of your vehicle.

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Driving Lights

What Are They?

If you live in a rural area, you may find that your stock headlights just can’t cut it on those long dark stretches of road. It can dangerous using your stock headlights that have a limited visibility because you might not have enough warning time to avoid animals, dangerous curves, or other obstacles on the road. That’s why we offer upgraded driving light systems!

What To Look For Before Buying

The same as with Fog Lights (see above): Power Consumption, Housing and Lens Material. Be sure to pay attention to the mounting style. Not all vehicles will be able to accommodate a driving light set up.

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Accent Lighting

Accent Lighting

What Are They?

Last but certainly not least, we offer lots and lots of accent lighting to trick your vehicle out with. Accent lighting is more for looks than functionality but some do serve a purpose like the Puddle lights from Racesport Accessories. These are primarily designed to light your foot pathway so you don’t step in a puddle or something worse when getting out of your car. And they come in cool designs too like vehicle manufacturer logos for those of you who really love your car, to Transformers Decepticon and Autobot logos. Of course, you can install these lights pretty much anywhere you like. We also have LED light strips so you can cut your own designs and mount wherever you like such as along your floorboards, glove box, side pockets… The possibilities are endless.

What To Look For When Buying

Type- Like I mentioned above, pay attention to what type of accent light you are buying. LED strips, puddle lights, security lights… We even have full underbody kits! Make sure you know what you’re getting!

Color- We carry all different colors like red, blue, green and alternating. Have them match the interior of your vehicle or mix it up. Have fun choosing your colors!

Remember, vehicle lights are subject to Department of Transportation rules and regulations. In addition, your local and state laws may vary on the legality of different types of lights. Always double check with DOT regulations and local laws before purchasing any type of vehicle lighting.

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5 Steps to Eliminate Headlight Dimming

Keep the Road Ahead Well Lit

1. Check Power Contacts, Grounds and the Battery

The electrical system needs solid contact to transfer power as efficiently as possible. Contacts that have grown dirty or crusted will have a higher resistance to power transfer, which means other parts of the system suffer. The first step is to check each of the power and ground connections. Make sure these are scraped and cleaned to bare metal, and that nothing obstructs the flow of power.

If this does not solve the problem, the battery itself may be the issue. Take the battery to an auto parts store to have it load tested. This is typically a free procedure, and if the battery is damaged or faulty, a new one can be purchased and installed easily. Batteries & power cells have an average life span of four years. Older batteries may be able to run the car without issue, but falter when a high-powered audio system kicks in.
2. Add a Capacitor
capacitors

Capacitors are devices that help regulate an electrical system. When voltage is too high, the extra power is stored in the capacitor. When voltage drops, the capacitor discharges that stored power in order to keep the current flowing.

A capacitor will not solve headlight-dimming issues if they are constant and major. However, if the headlight dims only rarely, and only when the amps are kicked into high gear, it could mean that they draw too much power too quickly for the system to handle.

For these minor power fluctuations, a capacitor is an ideal way to regulate the flow of power from the battery and alternator to the stereo system. Capacitors are measured in farads, which is a unit of capacitance. Two farads of capacitance for every thousand watts in the stereo system is an ideal level. It is actually higher than the typical recommendation, but it will allow the capacitor to recharge quickly and keep power flowing evenly.
3. Perform the Big Three Wiring Upgrade

There are three primary and important cables in the electrical system of a car with an auxiliary audio system. These “big three” cables, when upgraded, will vastly increase the capacity of the electrical system. This means that if the headlights are dimming because not enough power can flow to them through the system, they will now have plenty of juice to run. On the other hand, if the cause of dimming headlights is the power consumption and not a restricted power flow, this upgrade will cause the problem to worsen. This is because the audio system will be able to draw even more power, causing the headlights to receive even less.

The three cables that need to be upgraded are the alternator plus to battery plus cable, the chassis to engine block cable and the battery ground to chassis cable. Each of these cables can be replaced with either 1/0 gauge or 4 gauge wire in order to increase their carrying capacity.

In the event that this upgrade causes the problem to worsen, there is no need to revert to older wires. It is still a valuable upgrade in any case, and other solutions on this list will still solve the problem.
4. Install a Higher Output Alternator

The alternator is the source of all power when the car is running. The battery is necessary in order for the vehicle to start, but once it is running, all power usage comes from the alternator. If none of the steps above have helped the headlight-dimming problem, it is possible that the stock alternator simply does not put out enough power to feed everything in the electrical system. Headlights are easy to see, but every part of the electrical system will suffer from insufficient current.

Unfortunately, a high output alternator is an expensive solution. That said, it is a worthwhile investment for many vehicles and will last for quite a long time. For a 1500-watt sound system, the alternator needs to be able to produce around 220 amperes of current. Most alternators are designed with the standard vehicle hardware in mind, and will produce no more than 120 amperes of current. Music does not use the full 220 amperes the majority of the time, and only when it tries to draw that much power will the electrical system suffer. For such a sound system, an aftermarket alternator that produces around 300 amperes will be sufficient.

5. Install a Second Battery

Adding a second battery to a car with an aftermarket sound system is a good idea, especially of none of the other solutions above work and an alternator is out of the price range. A second battery is typically installed in the rear of the vehicle, near the sound system’s amp.

It is a good idea to isolate the batteries from one another. This way the primary battery is never drained when playing music, so the car never has issues starting. It is also a good idea to use two batteries with the same strength and of the same age. Using one new battery and one old battery leads to imbalances in power. The batteries will equalize these differences, but the constant change between them will shorten their life spans.

For a vehicle used to play music with the engine off, a second battery is virtually required. Without the engine running, the alternator does not provide power, and so the sound system is powered entirely by the car battery. This can lead to the battery draining and the car needing a jump-start.

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ADC and DAC Glossary

Sound Waves

Acquisition Time

Acquisition time refers to the time interval between the release of the hold state (imposed by track-and-hold input circuitry) and the moment that the voltage on the sampling capacitor settles to within 1 LSB of a new input value. The picture below shows the formula for acquisition time (Tacq):

where  N is the number of resolution bits, RSOURCE is the source impedance, and CSAMPLE is the sampling capacitance.

Aliasing

In the context of sampling theory, frequencies of an input signal that happen to exceed the Nyquist frequency are “aliased.” This means the frequencies of said input signal are replicated or “folded back” at alternate locations in the spectrum above and below the Nyquistfrequency. In order to prevent aliasing, you have to filter all undesired input signals, thus preventing the ADC from digitizing them. On the other hand, aliasing can actually be advantageous when undersampling.

 

Aperture Delay

Aperture delay (tAD) refers to the time interval in an ADC between the sampling edge of the clock signal (the rising edge of the clock signal in the picture below) and the moment that the sample is taken. The sample is taken immediately when the ADC’s track-and-hold goes into the hold state.

Aperture delay (red) and jitter (blue).
Aperture delay (red) and jitter (blue).

Aperture Jitter

Aperture jitter (tAJ) refers to the variation from sample-to-sample in the aperture delay, as shown in this picture above. Typical ADC aperture jitter values are significantly smaller than those of aperture delay.

Binary Coding (Unipolar)

Straight binary is a coding scheme that is typically used for unipolar signals. The binary code (zero scale to full scale) ranges from all zeros (00…000) to the positive full-scale value of all ones (11…111). Midscale is represented by a one (the MSB) followed by all zeros (10…000). This code is similar to offset binary coding, which accommodates the positive and negative values of bipolar transfer functions.

Bipolar Inputs

The term ‘bipolar’ indicates that the signal swings above and below some reference level. In single-ended systems, the input is typically referenced to analog ground, so a bipolar signal is one that swings above and below ground. In differential systems, where the signal is not referenced to ground but where the positive input is referenced to the negative input, a bipolar signal is one in which the positive input swings above and below the negative input.

Clock Jitter

Clock jitter is the deviation from the true periodicity of a signal that’s assumed to be periodic. Jitter can be noticed in characteristics such as the signal amplitude, the frequency of successive pulses, or the phase of periodic signals. Jitter can be caused by crosstalk with carriers of other signals and/or electromagnetic interference (EMI). In analog-to-digital and digital-to-analog conversion, the sampling frequency is normally assumed to be constant. Samples should be converted at regular intervals.

If there is jitter present on the clock signal to the ADC or DAC, then the instantaneous signal error will be introduced. The error is proportional to the slew rate of the desired signal and the absolute value of the clock error. Various effects can come about depending on the pattern of the jitter in relation to the signal. In some conditions, less than a nanosecond of jitter can reduce the effective bit resolution of a converter with a Nyquist frequency of 22 kHz to 14 bits.

Common-Mode Rejection (CMR)

Common-Mode Rejection is the capability of a device to reject a signal that is common to both inputs. The common-mode signal can be a DC or AC signal, or a combination of both. The Common-Mode Rejection Ratio (CMRR) is the ratio of the differential signal gain to the common-mode signal gain. You’ll more often than not see CMRR expressed in decibels (dB).

Crosstalk

Crosstalk is a measure of each analog input’s isolation from the other inputs. For ADCs with multiple input channels, crosstalk is signal that crosses over from one analog input to another. Usually, this value is expressed in decibels (dB). For DACs with multiple input channels, crosstalk is the noise that shows up on the DAC output when another DAC output channel is updated.

Differential Nonlinearity (DNL) Error

For an ADC, the analog input levels that trigger any two successive output codes should differ by one LSB (DNL = 0). Any deviation from one LSB is defined as Differential Nonlinearity (DNL). For a DAC, DNL error is the difference between the ideal output responses and the measured output responses for successive DAC codes. An ideal DAC output response would have analog output values that are exactly one code (LSB) apart (DNL = 0). (A DNL specification of greater than or equal to 1LSB guarantees monotonicity.) (See “Monotonic.”)

DNL for an ADC and a DAC.
DNL for an ADC and a DAC.

 

Digital Feedthrough

Digital feedthrough is noise that can appear on a DAC output when the digital control lines are toggled. In the figure, feedthrough on the DAC output is the result of noise from the serial clock signal.

Digital feedthrough.
Digital feedthrough.

Dynamic Range

Typically expressed in dB, dynamic range is the distance between the specified maximum output level of a device and the noise floor. An ADC’s dynamic range is the range of signal amplitudes that the ADC can resolve; an ADC with a dynamic range of 60dB can resolve signal amplitudes from x to 1000x. Dynamic range is especially important in communication situations where the signal strength can vary dramatically. If the signal is too great, it over-ranges the ADC input. If the signal is too weak, it will get lost in the converter’s quantization noise.

Effective Number Of Bits (ENOB)

ENOB specifies the dynamic performance of an ADC at a specific input frequency and sampling rate. An ideal ADC’s error is solely comprised of quantization noise. As the input frequency increases, the overall noise (particularly in the distortion components) also increases, thereby reducing the ENOB and SINAD. (See ‘Signal-to-Noise and Distortion Ratio (SINAD).’) ENOB for a full-scale, sinusoidal input waveform is computed from the following formula:

Force-Sense Outputs

This is a method of measurement where a voltage (or current) is forced at a remote point in a circuit, and the resulting current (or voltage) is measured (sensed). DACs with integrated output amplifiers, for example, sometimes include force-sense outputs. The inverting input of the output amplifier is available for external connection, and the feedback path must be closed externally.

Full-Power Bandwidth (FPBW)

An ADC is operated with an applied analog input at or near the converter’s specified full-scale amplitude. The input frequency is increased to the point at which the amplitude of the digitized conversion result has decreased by 3dB. That input frequency is defined as the full-power input bandwidth.

Full-Scale (FS) error

Full-scale error is the difference between the actual value that triggers the transition to full-scale and the ideal analog full-scale transition value. Full-scale error equals offset error + gain error, as shown in this figure.

Full-scale error for an ADC and a DAC.
Full-scale error for an ADC and a DAC.

FS Gain Error (DACs)

The full-scale gain error of a digital-to-analog converter (DAC) is the difference between the actual and the ideal output span. The actual span is determined by the output when all inputs are set to 1s, minus the output when all inputs are set to 0s. The full-scale gain error of any data converter can be affected by the choice of reference used to measure the gain error.

Gain Error

The gain error of an ADC or DAC shows how accurately the slope of an actual transfer function mirrors the slope of the ideal transfer function. Gain error is often expressed in LSB or as a percent of full-scale range (%FSR), and it can be calibrated out within software or with hardware. Gain error equals the full-scale error minus the offset error.

Gain error for an ADC and a DAC.
Gain error for an ADC and a DAC.

Gain Error Drift

Gain-error drift is the variation in gain error due to a change in ambient temperature, typically expressed in ppm/°C.

Gain Matching

Gain matching indicates how well the gains of all channels in a multichannel ADC are matched to each other. To calculate gain matching, apply the same input signal to all channels, and report the maximum deviation in gain, typically in dB.

Glitch Impulse

Glitch impulse is the voltage transient that appears at the DAC output when a major-carry transition occurs. Typically measured as nV•s, it equals the area under the curve on a voltage-vs-time graph.

Harmonic

A harmonic of a periodic signal is a sinewave multiple of the signal’s fundamental frequency.

Integral Nonlinearity (INL) Error

For data converters, INL is the deviation of an actual transfer function from a straight line. After nullifying offset and gain errors, the straight line is either a best-fit straight line or a line drawn between the end points of the transfer function. INL is often called ‘relative accuracy.’

INL for an ADC and a  DAC.
INL for an ADC and a DAC.

Intermodulation Distortion (IMD)

IMD is a phenomenon in which nonlinearity in a circuit or device creates new frequency components not in the original signal. IMD includes the effects of harmonic distortion and two-tone distortion. It is measured as the total power of those selected intermodulation products (i.e., IM2 through IM5) to the total power of the two input signals, f1 and f2. The signals f1 and f2 are of equal amplitude and very close to one another in frequency. The 2nd- to 5th-order intermodulation products are as follows:

  • 2nd-order intermodulation products (IM2): f1 + f2, f2 – f1
  • 3rd-order intermodulation products (IM3): 2 x f1 – f2, 2 x f2 – f1, 2 x f1 + f2, 2 x f2 + f1
  • 4th-order intermodulation products (IM4): 3 x f1 – f2, 3 x f2 – f1, 3 x f1 + f2, 3 x f2 + f1
  • 5th-order intermodulation products (IM5): 3 x f1 – 2 x f2, 3 x f2 – 2 x f1, 3 x f1 + 2 x f2, 3 x f2 + 2 x f1.

Least Significant Bit (LSB)

In a binary number, the LSB is the least weighted bit in the group. Typically, the LSB is the furthest right bit. For an ADC or DAC, the weight of an LSB equals the full-scale voltage range of the converter divided by 2N, where N is the converter’s resolution. For a 12-bit ADC with a unipolar full-scale voltage of 2.5V, 1LSB = (2.5V/212) = 610µV

Major-Carry Transition

At the major-carry transition (around mid-scale), either the MSB changes from low to high and all other bits change from high to low, or the MSB changes from high to low and all other bits change from low to high. For example, 01111111 to 10000000 is a major-carry transition. Major-carry transitions often produce the worst switching noise. (See Glitch Impulse.)

Monotonic

A sequence increases monotonically if for every n, Pn + 1 is greater than or equal to Pn. Similarly, a sequence decreases monotonically if for every n, Pn + 1 is less than or equal to Pn. A DAC is monotonic if the analog output always increases as the DAC-code input increases. An ADC is monotonic if the digital output code always increases as the ADC analog input increases. A converter is guaranteed monotonic if the DNL error is no greater than ±1LSB

Most Significant Bit (MSB)

In a binary number, the MSB is the most weighted bit in the number. Typically, the MSB is the left-most bit.

Multiplying DAC (MDAC)

A multiplying DAC allows an AC signal to be applied to the reference input. By feeding the signal of interest into the reference input and by using the DAC codes to scale the signal, the DAC can be used as a digital attenuator.

No Missing Codes

An ADC has no missing codes if it produces all possible digital codes in response to a ramp signal applied to the analog input.

Nyquist Frequency

The Nyquist principle states that, to allow an analog signal to be completely represented with no aliasing effects, the ADC’s sampling rate must be at least twice the maximum bandwidth of the signal. This maximum bandwidth is called the Nyquist frequency.

Offset Binary Coding

Offset binary is a coding scheme often used for bipolar signals. In offset binary coding, the most negative value (negative full scale) is represented by all zeros (00…000) and the most positive value (positive full scale) is represented by all ones (11…111). Zero-scale is represented by a one (MSB) followed by all zeros (10…000). This scheme is similar to straight binary coding, which is typically used for unipolar signals. (See Binary Coding, Unipolar.)

Offset Error (Bipolar)

The offset error measurement in bipolar converters is similar to the offset error measurement in unipolar converters. However, the error measured at zero-scale is at the midpoint of the bipolar transfer functions. (See Offset Error (Unipolar).)

Offset Error (Unipolar)

Offset error, often called ‘zero-scale’ error, indicates how well the actual transfer function matches the ideal transfer function at a single point. For an ideal data converter, the first transition occurs at 0.5LSB above zero. For an ADC, the zero-scale voltage is applied to the analog input and is increased until the first transition occurs. For a DAC, offset error is the analog output response to an input code of all zeros.

Offset error for an ADC and a DAC.
Offset error for an ADC and a DAC.

Offset Error Drift

Offset-error drift is the variation in offset error due a change in ambient temperature, usually expressed in ppm/°C.

Oversampling

For an ADC, sampling the analog input at a rate much higher than the Nyquist frequency is called oversampling. Oversampling improves the ADC’s dynamic performance by effectively reducing its noise floor. Improved dynamic performance leads, subsequently, to higher resolution. Oversampling is the basis of sigma-delta ADCs.

Phase-Matching

Phase-Matching shows how well matched the phases of identical signals applied to all channels are in a multichannel ADC. Phase matching is the maximum deviation in phase among all the channels, and is typically reported in degrees.

Power-Supply Rejection Ratio (PSRR)

Power Supply Rejection Ratio (PSRR) is the ratio of the change in DC power supply voltage to the resulting change in full-scale error, expressed in dB.

Quantization Error

For an ADC, quantization error is the difference between the actual analog input and the digital representation of that value.

Ratiometric Measurement

With ratiometric measurement, instead of a constant reference voltage, only a fraction of the signal applied to the transducer (i.e., the load cell or bridge) is applied to the ADC’s voltage reference input. This measurement eliminates any errors introduced by changes in the reference voltage. An example of ratiometric measurement using a resistive bridge is shown in the figure below.

Ratiometric measurement using resistive bridge network.
Ratiometric measurement using resistive bridge network.

Resolution

ADC resolution is the number of bits used to represent the analog input signal. To more accurately replicate the analog signal, you must increase the resolution. Using an ADC with higher resolution also reduces the quantization error. For DACs, resolution is similar but reversed—incrementing the code applied to a higher resolution DAC produces smaller step sizes in the analog output.

Root Mean Square (RMS)

2/2 (or 0.707) times the peak value, which is 0.354 times the peak-to-peak value.

Sampling Rate/Frequency

Sampling rate or sampling frequency, specified in samples per second (sps), is the rate at which an ADC captures (samples) the analog input. For ADCs that perform one sample per conversion (such as SAR, flash, and pipeline ADCs), the sampling rate is also referred to as the throughput rate. For sigma-delta ADCs, the sampling rate is typically much higher than the output data rate.

Settling Time

For a DAC, settling time is the interval between a command to update (change) its output value, and the instant it reaches its final value, within a specified percentage. Settling time is affected by the slew rate of an output amplifier and the amount of amplifier ringing and signal overshoot. For an ADC, it is essential that the time required for voltage on the sampling capacitor to settle to within 1 LSB be less than the converter’s acquisition time.

Signal-to-Noise And Distortion (SINAD)

SINAD is the ratio of the RMS value of the sinewave (input for an ADC, or reconstructed output for a DAC) to the RMS value of the converter noise plus distortion (without the sinewave). RMS noise plus distortion includes all spectral components up to the Nyquist frequency, excluding the fundamental and the DC offset. SINAD is typically expressed in dB.

Signal-to-Noise Ratio (SNR)

SNR is the ratio of the amplitude of the desired signal to the amplitude of the noise signals at a given point in time. For a waveform perfectly reconstructed from digital samples, the theoretical maximum SNR is the ratio of the full-scale analog input (RMS value) to the RMS quantization error (residual error). The ideal, theoretical minimum ADC noise is caused by quantization error only and results directly from the ADC’s resolution (N bits):

(Actual ADCs produce thermal noise, reference noise, clock jitter, etc., in addition to quantization noise.)

Signed Binary Coding

Signed binary is a coding scheme in which the MSB represents the sign (positive or negative) of a binary number. Thus, the 8-bit representation of -2 is 10000010, and the representation of +2 is 00000010.

Slew Rate

Slew rate is the maximum rate at which a DAC output can vary, or the maximum rate at which an ADC’s input can vary without causing an error in the digitized output. For a DAC with an output amplifier, the specified slew rate is typically that of the amplifier.

Small-Signal Bandwidth (SSBW)

To measure SSBW, apply an analog input signal of sufficiently small amplitude to an ADC so that its slew rate does not limit the ADC performance. Then, sweep the input frequency up to the point where the amplitude of the digitized conversion result decreases by -3dB. SSBW is often limited by the performance of the associated track-and-hold amplifier.

Spurious-Free Dynamic Range (SFDR)

SFDR is the ratio of the RMS amplitude of the fundamental (maximum signal component) to the RMS value of the next largest spurious component, excluding DC offset. SFDR is specified in decibels relative to the carrier (dBc).

Total Harmonic Distortion (THD)

THD measures the distortion content of a signal, and is specified in decibels relative to the carrier (dBc). For ADCs, THD is the ratio of theRMS sum of the selected harmonics of the input signal to the fundamental itself. Only harmonics within the Nyquist limit are included in the measurement.

Track-and-Hold

Track-and-hold, often called ‘sample-and-hold,’ refers to the input-sampling circuitry of an ADC. The most basic representation of a track-and-hold input is an analog switch and a capacitor. (See figure below.) The circuit is in ‘track’ mode when the switch is closed. When the switch opens, the last instantaneous value of the input is held on the sampling capacitor, and the circuit is in ‘hold’ mode.

Basic track-and-hold.
Basic track-and-hold.

Transition Noise

Transition noise is the range of input voltages that cause an ADC output to toggle between adjacent output codes. As the analog input voltage is increased, the voltages that define where each code transition occurs (code edges) are uncertain due to the associated transition noise.

Two’s Complement Coding

Two’s Complement is a digital coding scheme for positive and negative numbers that simplifies addition and subtraction computations. In this scheme, the 8-bit representation of -2 is 11111110, and the representation of +2 is 00000010.

Undersampling

Undersampling is a technique in which the ADC sampling rate is lower than the analog input frequency; a condition that causes aliasing. Given the Nyquist criterion, it is natural to expect that undersampling would result in a loss of signal information. However, with proper filtering of the input signal and with proper selection of the analog input and sampling frequencies, the aliased components that contain the signal information can be shifted from a higher frequency to a lower frequency and then converted.

This method effectively uses the ADC as a downconverter, shifting higher-bandwidth signals into the ADC’s desired band of interest. For this technique to be successful, the bandwidth of the ADC’s track-and-hold must be capable of handling the highest frequency signals anticipated.

Unipolar

For an ADC with single-ended analog input, the unipolar input ranges from zero-scale (typically ground) to full scale (typically the reference voltage). For an ADC with differential inputs, the unipolar input ranges from zero-scale to full-scale, with the input measured as the positive input with respect to the negative input.

Zero-Scale Error

(See offset error (unipolar).)

(Source material & images used with permission from Maxim, Analog and Mixed-Signal Semiconductor Manufacturing Company)

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Digital Audio Lossless/Lossy Codec Demonstration

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The topic of CDs versus MP3s is indeed an old topic that started around when MP3s first started gaining popularity in the mid-to-late 90s. The debate was probably at its hottest point around when the Napster controversy started up in the year 2000. However, anyone who remembers that controversy will know that it was about copyright infringment, not quality loss. What I intend to do with this article is give you audible examples of the quality loss inherent in the codec compression process.

What I’ve done here is I’ve taken a lossless audio file (WAV, specifically), put it into my digital audio workstation (Pro Tools 8), and I’ve meticulously lined up the waveforms of some lossy, compressed versions (MP3 and AAC) of the same audio file so that they’re exactly accurate with each other. Let me explain the last part of that a little better: I zoomed in to the waveforms down to the level of individual samples and lined them up perfectly, or at least as perfectly as the human eye, ear and the Pro Tools digital audio workstation technology can manage. When I say “samples,” I’m referring to the same samples as the Sample Rate of CDs (which is 44.1 kHz). For anyone who doesn’t yet know, the Sample Rate refers to how many times in a single second that the audio source is sampled. You can think of it like many, many snapshots taken in a row.

Anyway, when you line up audio files perfectly and play them together, what you’ll hear is an increase in volume due to what’s known as constructive interference. In the case of the inverse, destructive interference, you would hear a decrease or a total cancellation of volume due to the waveforms being precisely opposite. The topic of constructive/destructive interference is indeed an interesting one. Anyone who’s taken a Physics class in school has probably covered it at some point, but I won’t delve into it too deep in this article.

Moving on, once I lined up the audio files (one lossless, one lossy), I inverted one of them so that when the two files were played together, all that was audible was the audio data that was thrown away during the codec compression process. I’ve often explained it as being completely convinced that there’s jelly on your peanut butter & jelly sandwich, but without any jelly actually being there. Also, I should mention that I encoded these lossy files through iTunes. The MP3 is 320kbps CBR, the highest quality MP3 available, and the AAC (m4a) is “High Quality” 128kbps, the iTunes standard quality (which I consider to be cassette quality at best). For your convenience, I’ve also included links to the files in case your browser doesn’t allow flash or isn’t up-to-date. Anyway, without any further ado, enjoy the demonstration!

PT Grimm – Crummy (wav) by psivertsen

PT Grimm – Crummy (mp3) by psivertsen

PT Grimm – Crummy (m4a) by psivertsen

PT Grimm – Crummy (inv mp3) by psivertsen

PT Grimm – Crummy (inv m4a) by psivertsen

http://soundcloud.com/psivertsen/pt-grimm-crummy-wav/download

http://soundcloud.com/psivertsen/pt-grimm-crummy-mp3/download

http://soundcloud.com/psivertsen/pt-grimm-crummy-m4a/download

http://soundcloud.com/psivertsen/pt-grimm-crummy-inv-mp3/download

http://soundcloud.com/psivertsen/pt-grimm-crummy-inv-m4a/download

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How To Perform The Big 3 Upgrade

Big 3 Upgrade Kit
Performing what is known as the “Big 3” upgrade to your vehicle will improve the performance of your electrical system and increase its current handling capabilities. This should be the first upgrade done to your electrical system which will then allow you add more powerful audio system components. Factory wiring is thin and insufficient for running anything but basic audio systems. Larger diameter wires will be added to the existing factory wire (or swapped out entirely), usually 1/0 gauge wire to get the best current flow and least resistance. This new decrease in resistance will reduce light dimming, reduce voltage drops, stabilize voltage and current flow, and decrease the strain being put on your vehicle’s electrical charging system. Additionally, you can then add batteries, capacitors and more alternators onto your system.

The Big 3 Upgrade is a Swap or Addition to These Three Cables:

  • Alternator positive cable that runs to the positive terminal of the battery
  • Negative battery cable that runs from the battery to the vehicles chassis
  • Chassis grounding cable that runs to the engine block

When to Perform the Big 3 Upgrade

This upgrade should be performed on any vehicle before adding a High Output Alternator. Additionally, any vehicle with an after-market amplified stereo system will benefit from this upgrade. This should be the first upgrade you make before adding additional batteries, capacitors, or alternators, especially if you need slightly more current before other upgrades.

What Will I Need to Perform This Upgrade?

We have “Big 3 Upgrade Kits” that come with everything you need to perform this modification on your vehicle except for standard or exotic tools. However, here is a basic list of what you might need to perform the upgrade:

  • High Capacity Power Cable Long Enough for Vehicle (Most Common is 4 AWG)
  • 5/8” or Smaller Heat Shrink Tubing
  • Ring Terminals/Lugs that Fit the Cable
  • Two Terminals that Fit Battery Posts or Terminals
  • Wire Cutters of Sufficient Size
  • Plastic Cable Ties (Zip Ties)
  • Solder and Soldering Iron
  • Crimpers of Sufficient Size
  • Wire Strippers of Sufficient Size
  • Heat Gun
  • Standard Tools (Wrenches, Screwdrivers, Etc)

How Do I Perform This Upgrade?

Your vehicle should be parked in a safe location away from the elements and the engine should be completely cool before starting work.

1Get Your Cables Ready

Most Big 3 upgrades use 1/0 AWG cable, but you need to make sure whatever cable you use can meet the current demands of your system. If you don’t know the length of cable you need, measure, ask your local dealership or overestimate. You must use 4 AWG or greater high strand count cable and never solid core wire. Measure the lengths of the factory cables used and cut your new wire slightly longer than those lengths, usually 1 to 1-1/2 inches longer. A vehicle in motion is subjected to vibrations and bending which could disconnect these cables. Most upgrades keep the factory wire in place as an extra line of defense against mishaps.

2Choose Wiring Path & Cap Cables

Choose your path to run the wire. Keep in mind that the cable should stay away from fans, belts, moving parts or surfaces that heat up such as exhaust outlets and the engine block. Cap each end of your three new cables. You need to insert the wire into the wire lug and use enough solder to melt into the strands of cable without melting the cable itself. Use heat shrink tubing to seal and weather proof the ends of your new wire connectors.

3Disconnect Electrical Equipment

Disconnect the negative cable on your battery and then disconnect the positive cable in that order. Be mindful of any capacitors and additional batteries you may have in the system. Discharge and capacitors or disconnect any other batteries to create a safe working environment. Check out our article titled, “How to Discharge a Capacitor” if you need help.

4Connect Your Cables

It does not matter what cables you start with, we prefer starting with the battery negative. If your stock ground is sufficient, just run your wire alongside the original factory wiring and bolt up to the ground. Most of the time however, you will need to drill a new hole into the chassis, scrape off all paint around the new grounding location, clean the surface thoroughly,  and make your connection. You want bright shining metal to connect to.
Now go after the alternator to battery positive wire. Locate the alternator and find the positive post that connects to the battery. It might run to a fuse block or it could go straight to the battery, be careful. Disconnect the stock wire, add the new wire to it, and bolt it back on. No need to get rid of the factory wiring unless you want or need too.
Lastly, it’s time to tackle the grounding cable that runs from the chassis to the engine block. This is the most important cable in the Big 3 because the alternator, which grounds through the engine to the chassis, is your “Absolute Ground”. Disconnect the wire at both ends and clean the contact surfaces with a wire brush and cleaner.  Run your new cable alongside the old one and either use the factory chassis ground or drill a hole and make a new ground. The other end of the cable will connect back to the bolt located on the engine block.

5Secure the Wiring

Now take cable zip ties every 6 inches or so and secure your new wire to anything that will remain cool and does not move.

6Check Your Work

If everything is connected snugly, and correctly, you can now connect your battery positive cable first and then your battery negative cable back up and enjoy the new electrical freedom you have. Turn your vehicle on and check for any vibrating wires or connections and secure them when the engine is off and the battery ground is disconnected. If your charging system survived the upgrade, it should read 13.8 to 14.4 Volts when the engine is on.
We highly recommend you take a Digital Multi-Meter and measure the resistance of your newly installed cables before connecting the negative battery cable. Your ground from the battery to the engine block, and the positive terminal on the alternator to the disconnected positive cable on the battery should measure less than one ohm.
Once you’re done, go to our Facebook page or Forums and show us pictures of your Big 3 Upgrade!
NOTE: This article is a generalization and some vehicles may require different methods, tools, or material to perform a Big 3 Upgrade. Always consult your local installer or mechanic before beginning this installation.

 

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What Is the Gain Setting On an Amplifier?

bb3000d

The objective of an audio amplifier is to boost the incoming audio signal that is supplied by a radio or receiver. When we say audio signal, we mean a low voltage electrical current that a radio outputs which has all the information of your musical selection in it. The typical audio signal from a CD player averages about 0.5-2V which is not enough to power an audio speaker or subwoofer by itself; this is why we need amplifiers. The amplifier will turn that 0.5V into 20V or more and feed that to the speakers, which in turn produce music that we can hear. Ok great to know, but what is the “gain” knob on my amplifier?

If you adjust the gain knob while listening to your music playing, you will notice an increase and decrease in volume. However, this does not mean the gain control is a volume control. Let’s repeat that. Your gain knob is NOT a volume control knob. Got it? Confusing? YES! The purpose of the gain control is to level match the head unit’s output voltage (around 0.5V) to the gain structure of the amplifier (how much it amplifies a signal) so that the signal is not over driven which would produce clipping and distortion.
Think of it like this, you have two radios and each of them has a volume knob that goes from 0 to 30. One radio outputs a signal at 0.5V and the other outputs that same signal but at a whopping 5V. The amplifier will amplifier both of those voltages by the same percentage. Turn both radios to a volume of 15 (halfway), will the loudness of the music be the same for both? NO! The 5V radio will sound much louder in comparison to the radio only putting out 0.5V. Now turn both radios to a volume level of 30, which is maximum volume. What will happen? The 0.5V radio will sound loud, but the 5V radio will have damaged your equipment, exploded, or sent the amplifier into protection mode. This is where the gain comes in. Using the gain, your radio’s maximum volume will make the amplifier loud but not damaging. The 0.5V will be loud and the 5V will be louder but won’t damage anything. You can set the gain to a point where your equipment gets loud at about 3/4th of your total volume swing (ex: 0-30).
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How to Adjust Amplifier Gains Using a Digital Multi-Meter

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The gain adjustment control on an amplifier is one of the most misunderstood concepts in the car audio world. Well, basic concepts that is. The purpose of the gain control is to level match the  head unit’s output voltage to the gain structure of the amplifier so that the input is not overdriven which would introduce clipping.

We first covered how to set your gains by ear in the article titled “How to Tune and Adjust Amplifier Gains and Bass Boost”, however this is not a great method to use because all of our ears are different and we often can’t hear the most deadly distortion. For those of us with a Digital Multi-Meter (DMM), setting your gains this way is the most effective method aside from using an oscilloscope.

Let’s get started.

Step 1: Disconnect the positive speaker wire(s) from the positive terminal(s) on the amplifier.

Step 2: Turn off all EQ settings or set them to zero, such as Bass, Treble, Loudness, Bass Boost, Processing and EQ functions.

Step 3: Turn the input sensitivity (gain) to zero. For most amplifiers, this is counter clockwise (CCW) to the farthest point. Make sure the input voltage selector is on “Low” if the amplifier has one.

Step 4: Set the head unit volume to 3/4th of its maximum volume. Turn your radio dial to it’s maximum volume and multiply that number by 0.75, this will get you 75% of your maximum volume.

Step 5: Now we must find the voltage that we need to set the gain to. Voltage = square root of watts x ohms. For example, a 500W RMS amplifier at 2 Ohms would configure like this: 500W RMS X 2 Ohms = 1000W. Now take the square root of 1000W and your voltage should be 31.62V if you’re running an amplifier with one gain control. Some amplifiers have 2 gain controls so treat it as two separate amplifiers. If the amplifier is 100W RMS by 4-channels for a total of 400 watts but has two gain controls, use the power output of ONE channel and use that for your voltage calculations. (EX: Square Root of 100W RMS x 2 Ohms = Voltage for each gain control per channel.)

Step 6: Make 100% sure the positive speaker wire(s) are disconnected from the amplifier. Once double checked, insert a test CD with a sine-wave test tone at 0dB level in the frequency range of 50Hz to 60Hz for a subwoofer amplifier or 1,000Hz for a midrange amplifier. Set the head unit to repeat for continuous play of the test tone.

Step 7: Connect a digital multi meter set to AC Volts to the speaker outputs of the amplifier. The positive voltmeter lead will touch the positive speaker wire terminal and the negative lead will touch the negative speaker terminal. If everything is done correctly, a low voltage will be displayed on the voltmeter, usually 6V or below. If you get a high voltage right away, repeat steps 2 and 3. Slowly turn the input sensitivity (gain) up on the amplifier until the target voltage you calculated earlier is reached.

Step 8: Adjust every amplifier in your system using this method; each amplifier is now set to its maximum unclipped output level. Turn the volume on your head unit to zero and turn it off.

Step 9: Reconnect all the positive speaker wire(s) to their respective positive terminals. Double check all wiring and proceed to turn the headunit on. Remove the test tone CD and play a musical track that you are familiar with. Listen for any distortion in the form of buzzing, crackling, hissing, whomping, and various other noises that intrude on the instruments of your music.

This is an accurate way to set your gains to prevent distortion and clipping in your system but it is not the absolute best method. If you really need it done right, use an oscilloscope which can show you if your setup is clipping and distorting or not.

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Difference Between Graphic and Parametric Equalizers

Equalizers have been seen a lot in car audio headunits and home audio setups. They both serve the same function; to adjust and enhance the strength of the frequencies in the signal running through it. Most individuals are familiar with bass and treble controls from stock car stereo systems. These are simple equalizers and in no way unleash the full potential of your music.  The two main equalizers are known as Parametric and Graphic and they both have different ways of functioning and tweaking your sounds.

Graphic EQ:

Graphic Equalizers- Clarion EQS746

The most common type of equalizer is the graphic EQ which is composed of a row of sliders that are pushed up or down to boost (raise dB) or cut (lower dB) bands of frequencies. You will find these equalizers as physical sliders, knobs or in a digital format found on most aftermarket car stereos.  Graphic equalizers will have a number of bands, or frequencies, that it can boost or cut. For example, a seven band graphic EQ like the Clarion EQS746 can boost or cut 7 fixed frequencies which are 50Hz (bass), 125Hz (mid-bass), 315Hz (upper midbass), 750Hz (lower midrange), 2.2kHz (midrange), 6kHz (upper midrange) and 16kHz (treble or high-frequency). The frequency can be boosted or cut by a range of +/- 12dB for this EQ but could be different for other equalizers.

So, what about all of the other frequencies, are they left out from getting a boost or cut? The Graphic EQ drags frequencies along with it, for example if you take 125Hz and cut it, the surrounding frequencies will cut with it in a slope pattern. The farther the frequency is away from the frequency being cut, the less it is cut. This might seem preposterous to some, but with 20,000 frequencies available, a 20,000 band EQ is not practical. Essentially, graphic EQs have fixed center frequencies (ex 125Hz), fixed bandwidth (frequency range the boost/cut will effect), and adjustable level (boost/cut in dB). What if you want to cut 100Hz and ONLY 100Hz? Say hello to the Parametric EQ.

Parametric EQ:

Parametric Equalizers

The Parametric EQ is technically a different tool all together and best used after tweaking your graphic equalizer. The objective of this EQ is to shape the sound very precisely at each frequency by adjusting the level (boost/cut), the center (fixed) frequency and the bandwidth (Q) of each frequency. Think of Parametric EQs as the surgical work when it comes to frequencies.  315Hz is your culprit and seems too loud giving you a weird musical response so you cut the 315Hz fixed frequency and only that frequency. This won’t affect the surrounding frequencies like the graphic EQ does. It still sounds bad however, so you decide to up the bandwidth (Q) and bring a few other frequencies near 315HZ down as well. So, from 300Hz to 330Hz all of those frequencies will be cut in a sloping pattern, with the 300Hz and 330Hz receiving the least amount of cut.

To wrap it up, a graphic EQ gives you the quick and dirty frequency adjustments while a parametric EQ lets you go in with surgical precision and finish the job. Get a parametric equalizer and fiddle around with it, you may be surprised at the kind of music quality you can achieve.

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The Importance of Proper Gauge Power and Ground Wire

IMGP0788-e1321118062262

AWG is the American Wire Gauge system that standardizes wire diameters predominantly in the United States and Canada. This standard is determined by the total cross-sectional area of the conductor portion of the wire, not including the outer jacket (casing). The American Wire Gauge abbreviation (AWG) is often referred to as gauge, for example, 2AWG is the same as 2 gauge wire. History lesson aside, these terms are interchanged frequently and will be in this article. Read our full article titled “Wire Gauge Sizes and the American Wire Gauge (AWG)“.

So, why all the talk about wire gauge and the American standard? Other countries have different ways of rating their wire gauge. For example, 2 gauge wire using the AWG standard is not the same as 2 gauge wire from another country. This is where we run into trouble. You may think you have 2 gauge wire but in fact it could be much less, and given your power demands, will cause things to heat-up. Keep reading.

The objective of any wire is to transfer current a set distance with the least amount of resistance. Amplifier power wire is no different so it’s crucial that the correct gauge be used when powering your system. The rule of thumb: “The Bigger the Better”. This of course depends on the application but works for amplifiers most of the time. Always refer to the owner’s manual for what gauge wire to use and make sure to purchase “True to Gauge” wire. What happens when you’re using a wire size that is too small for your application? A few things:

1) The wire could melt because of the large amount of current flowing through it in comparison to the cables current handling capabilities. The smaller the wire diameter, the higher the resistance to the flow of energy becomes. When you have high resistance you create heat, much like a toaster, which will begin to toast things.

2) Your amplifier will not receive the proper voltage that it needs to operate at its peak efficiency. This means the performance and sound quality of your system will be hampered. Voltage is a term for how much work can be done by electrical current, so the lower the voltage the less work is being done which means less amplifier power. What is the point of a great sound system when it produces bad sound?

3) Damage to the amplifier could potentially occur when there is not enough current flowing to its circuits, especially during musical peaks. The amplifier will ask for a sudden boost in current which the wire size could not deliver. Think of it like jumping on a trampoline and suddenly hitting a tree branch, never a good thing. Also, If there is a lack of power and the grounds are not isolated well enough, the 12V ground could leak current into the the signal ground and blow the preamp stage.

Using the proper gauge power AND ground wire kit is going to protect you, your passengers, your vehicle and other vehicles or pedestrians on the road. Don’t risk running smaller cable then what your sound system demands. At some point your wire could light up like a firecracker and melt everything around it, such as carpeting, plastic and insulation. Once the burning cable touches the chassis it could arc and blow all of the other electronics in your vehicle. The more power you have the larger your wire needs to be. Read our article titled “What Gauge Wire Do I Need to Install My Amplifier?” for the best size wire for your amplifier. As you add additional wire to a battery it needs to be fused at the battery to protect the wire, not the equipment at the other end which should have its own fuses.  Proper gauge wire is not to protect your equipment; it’s to protect your wire which protects you.

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