I have 2 seperate 2 channel amps that I am planning to run together. Would it work or make sense to split the source, and have one set to each amp?

Run together how? Each pushing separate speakers? Y-cables to the inputs is fine. Both pushing the same speaker? Unless you bi-amp (and I will not go into the debates on that) you could save time and just go throw them directly into a lake.

Usually you can get away with splitting the source with a y cable or similar. If it sounds bad this way you may need to use a line driver to handle the fanout. Line drivers are designed for impedance matching purposes like this.

What are you trying to accomplish?
What amps?
How many speakers?

If you only desire stereo and if your amps are "bridgable", bridge the amp and run one amp to one speaker and do the same with the other. :)

No I do not want them to both push the same speaker.

2 amps, 4 speakers total. Stereo setup. I am going to try splitting the source, and if it doesn't sounds good, I will attempt to bridge them.

No I do not want them to both push the same speaker.

2 amps, 4 speakers total. Stereo setup. I am going to try splitting the source, and if it doesn't sounds good, I will attempt to bridge them.

you can easily split the signal without any SQ loss, its done all the time in active setups. No reason a simple RCA Y-cable isnt 100% okay.

The bigger question here would be why 4 speakers?

Line drivers are designed for impedance matching purposes like this.

there is no impedance matching here. Source impedance is very low, load impedance is very high. You can pssively split the signal a humdred times without any 'degradation'.

Source impedance is very low, load impedance is very high.

Statistically you would be correct, but your statement is not absolutely true.

Since I would never make assumptions about the nature of unknown equipment, my statement was thusly worded.

I do this kind of thing in my home setup and it works fine. A simple single RCA to dual RCA splitter works fine coming out of a receiver's pre-outs. I only use a single splitter now, but at one time I used a splitter and then had 2 splitters off of that. Now I have different amps that I can set to "parallel" input and so I only needed to split the signal once to go into 2 amps, my old amps only had bridge and stereo so I had to split the output into 4 separate signals to go to each channel.

It baffles me why receivers only have a single sub out...

...The bigger question here would be why 4 speakers?
Inquiring minds want to know!!! Are these for two separate areas played at once, or are the speakers in the same room?

but your statement is not absolutely true.

Neither is yours....you should have covered that before nitpicking.

It baffles me why receivers only have a single sub out...

maybe because for the extremely small percentage of people who actually use multiple subs, a y-cable accomplishes what a second sub out would... ;)

Actually, those using multiple subs should be using something like a QSC DSP322UA to split the signal between each of the subs and then individually manage their characteristics.

Neither is yours....you should have covered that before nitpicking.

Of course it is. You may want to reread.

i wouldn't disagree with that dennis...

however, that doesn't change the original statement...

No I do not want them to both push the same speaker.

2 amps, 4 speakers total. Stereo setup. I am going to try splitting the source, and if it doesn't sounds good, I will attempt to bridge them.

I'm not sure bridging gets you where you want to go, unless you are talking about something different from typical amp bridging (turning two channels into one more powerful one).

Chances are good you'll sound just fine with a Y cable.

One possible problem that I can think of. If you turn one of the amplifiers off, it's input circuit can do nasty things to the input signal to the other amplifier. Remember when tape recorders would to that nasty thing to your pre-amps main output? Then they added buffer circuits to the pre-amps tape out.

my answer is "it depends" on what amps you are using and what preamp.

What preamp, pre processor or receiver are you using?
What amps are you using?

Some preamps have multiple outputs, dual RCA, RCA and XLR. If this is the case then you can attach each amp to each output.

Some power amps provide the line level inputs and outputs so they can be daisy chained. Another option.

Otherwise, the Y splitter is a simple solution if you amplication does not have the features I mention.

Quite simple really....

Use the "Y" cables. If that doesn't work, then worry about plan B.

Odds are you'll be just fine with the "Y"s.