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can i connect 2 amplifiers together (parallel) with the same inputs to increase the output power?

if i have 2 of the same amplifiers or very similar, can i connect them to the same inputs and join the outputs together. will this increase the output power of the system? they are both old amps and are expendable. i have some fairly powerful speakers that will take double plus what the amp already puts out. - headphone to component audio cable (L/R) - split both the L and R channels - connect to amps and adjust to similar settings - connect both the R outputs into one speaker (making sure to match the +/-ve ) and same again with the L outputs.

Bigev5 years ago
Split the input into two parts, left and right signal. The input of the amps should be a stereo input. Feed the one a left signal by splitting the left signal input cable into two separate but still identical signals. Plus both sides of the left signal into the right and left inputs of the one amplifier. Then feed the other the right signal in the same fashion. Then take the stereo output of each of the amps and split it up, one part of the stereo signal from each amp to it's own individual speaker. By the end you should be using one source, divided to two amps, to power four speakers. Two for the left, and two for the right. This utilizes all parts of the amplifiers for maximun power output. Or so I imagine.
dosadi4 years ago
I know this is an old question, but I figured I'd comment for anyone else interested... If you want to convert a stereo amp into a mono amp driving a single speaker, you need what is called a bridging circuit. Some amps have them built in, mostly car stereo amps. If it has one, there will be a bridging switch to enable it. Once turned on, the amp has to be hooked up a particular way. The speaker is connected to the + of the left channel and the - of the right channel. If you still have the amp manual, it will show how to do this. A bridging circuit can be built for amps that don't have one, but it isn't trivial. It basically splits the signal into two, one of which is 180 degrees out of phase from the other. These are then used to drive each channel of the amp. You can find one by googling for "bridging adapter circuit". You will also need to make sure your speakers can handle the additional power. And even then, it won't make much difference. Even though a bridged amp delivers 4 times the power of the regular stereo configuration, human hearing works on a log curve and that is only a 6 decibel increase in sound. Audible, but nothing earth-shaking.
NachoMahma5 years ago
. Connecting the outputs can cause major problems - if the output levels are not matched, the amps will be fighting each other. The easiest solution is to parallel the inputs and run two sets of speakers.