Wiring amplifiers to split channels, I'm sure I can make a bang, can anyone help?

I currently run a 25watt RMS T-class amp of 4 ohms into four 100watt 8 ohms speakers wired in pairs- so each pair is 4 ohms. I have just acquired a second identical amp. Obviously, there is much capacity in the speakers. I was thinking to split the input and send left channel to one amp and right channel to the other and use the sum of each amp to power each pair of speakers to maintain ohmage but increase power. Can someone comment on my intentions and make sure I wire correctly and don't cause irreparable disharmony?

If my technical knowledge will cause calamity, might a suggestion of how all the kit can be utilised be offered?

Advance thanks for the benefit of your wisdom,

M

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Downunder35m10 months ago

It depends on the input impendance of your amps.
One way, if they and the source tolerate it would be a simply y-cable - so 2 RCA inputs and 4 RCA outputs.
Half decent amps offer a bridging function where the input signal can be send to the next connected amp.
If neither fits than you need to make a splitter that matches both the output impendance of your source and the input impendance of the amps.

So I would start by checking the amps for options and only use a simple y-cable as the last resort.

Agreed. What you are effectively trying to do is called Bi-Amping. Typically
this is done to drive the high pass and low pass (mid to high-range and
bass) separately, but it can also be used in the way you're intending. Ideally you would use a pre-amp that has a pair of outputs for each channel, but the Y-cable method suggested would also work.

Bi-amping has two main configurations, Horizontal and Vertical. As both your amps are identical you can use either, and as you're not splitting high-pass and low-pass filters it really doesn't matter which method you use.

In the attached image just assume that Left/Right HP and LP represents each of your four speakers.

7_Vertical_Bi-Amp.jpg
KittenSniffer (author)  ThirdEarthDesign10 months ago

So the amps are simple and definitely non-posh (they sound quite nice though) but have a twin RCA input, left and right channel output, an on switch and volume control. No VU meter or bridging options.

Speakers- although there are four, they are wired in parallel so essentially, I've got one pair of speakers with no bi-amping extra terminals on the back.

So, can I feed the sum (both outputs) of L amp into L speaker and sum of R amp into R speaker or might there be interference/explosions?

And, preamp options? Otherwise it's Y cables...

What you're effective doing at the moment is Bi-Wiring, not to be confused with Bi-Amping, which is what you are trying to achieve with the additional amp.

What you need to do is split your audio source. Assuming that you are using a CD player with RCA left and right outputs, you want to use the Y-cable to split each channel into two further outputs, effectively giving you two left outputs and two right outputs.

You then plug one left and one right into one of the amps L/R inputs, plug the other pair of left and right into the other amps L/R inputs.
Alternatively you can wire it as shown in the diagram I attached previously, where one amp is effectively used to do only the left channel, and the other is handling the right. This wiring variation is what differs between horizontal or vertical bi-amping.

You then wire up each of the four speakers in the normal fasion (not bi-wiring as you're now bi-amping).

The only question mark here is the detriment to the audio source by being split using the Y-cable, at the very least you should make sure you are using good quality cables with quality RCA connectors. As I said before, in an ideal world you'd use a pre-amp (this sits between the audio source and the two main amps), but this isn't necessarily required.

Oh, one more that I have from installing amps in cars:
Most amps can be set or bridged to mono mode.
In that mode only one input channel is used to drive all speaker outputs of this amp.
Of course a proper amp also allows the same for the output.
Meaning when set to mono for the input you can either connect 2 speakers to work in sync or bridge the output as well and connect a single speaker over both output terminals.
Makes it very easy to get massive power levels without the need to add complicated and often lossy ways of multiplying the input signal.

As an example with 3 amps and a bunch of speakers:
Input RCA goes on the first amp and from it's loop connection it goes to the second where the story repeats.
So all amps are already on the same input ;)
There is usually a potentiometer to set the input level - this should be set to the level of the stereo supplying the signal or below that if you don't need the full output power.
First amp goes to two speakers for the left and right front signals.
Second amp goes to two speakers for the rear left and right signals.
Third amp is in bridge mode for the output and supplies power to the massive sub.
You see, things can be very easy with the right amps ;)
Especially if they offer a basic frequency range selection, this way the normal speakers won't be bothered with the low base signal while the base speaker won't even "see" the high frequencies.
Keeps amps cooler and makes them a little bit more efficient.

Standard amps or those kits you find online usually have nothing else than input, output and power.
If that is the case for you than it means you have to check what your amps can tolerate and match the input signals accordingly.
But if the amp is too basic it means no matter what you try you might have interference problems if a high output load affects the input impendance.
So make sure the power supply is capable of supplying what is required to avoid wondering why the sound goes crappy when you crank it up.

KittenSniffer (author)  Downunder35m10 months ago

So the amps are simple and definitely non-posh (they sound quite nice though) but have a twin RCA input, left and right channel output, an on switch and volume control. No VU meter or bridging options.

Speakers- although there are four, they are wired in parallel so essentially, I've got one pair of speakers with no bi-amping extra terminals on the back.

So, can I feed the sum (both outputs) of L amp into L speaker and sum of R amp into R speaker or might there be interference/explosions?

And, preamp options? Otherwise it's Y cables...

iceng Downunder35m10 months ago

+1