For this how-to, I’m going to use the DC Audio 7.5k .
For the most part, “Strapping” – aka ‘Bridging’ – TWO amps together is done to get Double the @1ohm Power Rating of One Amp. This makes the setup – AFTER “strapping” – stable ONLY to a 2-ohm final load . That, in of itself, is fairly confusing so here’s an explanation…
First, it is of the UTMOST IMPORTANCE that you ONLY ‘strap’ two IDENTICAL TWIN AMPLIFIERS! Moreover, it is also important to make sure that the amplifiers have the ability to be strapped (i.e. the features necessary to successfully perform this), and that ‘Strapping’ is a manufacture confirmed ability of the amplifiers.
- 4-ohms: 2000 watts x 1 ch.
- 2 -ohms: 4400 watts x 1 ch.
- 1-ohm: 7500 watts x 1 ch.
From the above specs, we establish that ONE DC Audio 7.5k is able to put out 7,500w RMS @1-ohms. Therefore, in theory, If we strap TWO DC Audio 7.5k together we can achieve 15,000w RMS @2ohms!!
The most crucial part of successfully Strapping two amps together is the Wiring! Starting with the Easy part, RCAs:
- Step 1. Connect the Master amplifier to the head-unit (duh!) and set the amplifier’s output-master/input-slave switch to Output Master.
- Step 2. Set Slave amplifier output-master/input-slave switch to Slave Input.
- Step 3. From the ONE RCA-Connector – that has a line from said switch – Connect an RCA cable from the Master to Slave amplifier.
DO NOT USE THE PAIR OF RCAS LABELED ‘OUTPUT’!!!! This “Output” will ONLY send an AUDIO SIGNAL, and Will Not allow for the following important part to happen……
Intermission: The Output-Master/Input-Slave Switch , if you haven’t already figured it out, will turn one amp into the Masterand the other into the Slave. But what does this mean exactly? This means – The Master amp will be in absolute control of the Crossover Points, The Gain, & The Remote Level Control. Implied, the SLAVE will have absolutely NO control abilities, those settings will be turned Off . Therefore to “Tune” the amps – plural – you ONLY ‘Tune’ the Master amp!
Next part of the install is where everyone gets lost; the speaker wire connections.
- Step 1. Connect 12-Gauge Speaker Wire from the Positive (+) Speaker Output on the Master amp to the Positive Terminal on the Subwoofer (+). Amp (+) to Sub (+)
- Step 2. Connect 12-Gauge Speaker Wire from the Positive (+) Speaker Output on the Slave amp to the Negative Terminal on the Subwoofer (-). Amp (+) to Sub (-)
- Step 2.5. Please Re-Read Step 2 . This is the part EVERYONE gets wrong.
- Step 3. Connect 12-Gauge Speaker Wire from the Negative (-) Speaker Output on the Master amp to the Negative (-) Speaker Output on the Slave Amplifier. Amp (-) to Amp (-)
These connections is what Physically ‘bridges’ the amps together!
From this point on you can go about the install as you would any other install. Make sure all your connections are made properly, tighten everything down, mount what needs to be mounted, etc… Then, start the Tuning process; tune the MASTER AMP ONLY!!!
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