Okay, well if you don't want to loose audio quality and signal strength from using Y splitters (or a single three-way splitter) then you'll want something like the Audio Control Matrix that will take input on channel 1 and feed it to the outs across all three stereo outputs at line level strength.

Run your front & rear lines direct to your amp, run the subwoofer line through the Matrix and out to the three sub amps.

 

How do you lose quality, and particularly signal strength, by using a Y-cord?

You would have to have a very high output impedence on the deck and a very low input impedence on the amplifiers before the current draw (of which there is almost none) would cause a voltage sag in the output. The likelyhood of this happening is very remote and the amp gain settings would compensate regardless.

 

Maybe I was mistaken. I've always been told that Y splitters will drop your volume by about 3db. I've noticed in setups I've ran that this is the case and that the audio quality suffered, but these were pro-audio setups not car audio.

 

So with that control matrix, I would run my sub output from head unit to the main input on that control matrix, then run the 3 outputs on it to 1 sub each?

 

Another quick question, I'll be building my own sub box, is there a reason everyone uses mdf board? Or would osb board work just as good? Just wondering as my job we produce osb board so I can get a good discount on it.

 

MDF is cheap, dense, cuts and machines well, and is void free.

If you build it well, there is no reason you cannot use OSB.

 

Ok thanks again dukk, I wasn't sure there and would prefer osb cause as I said I can get it cheap. Plus osb is easier to work with in my opinion.

 

Got another one for you guys, haha sorry. I was told I'll need an adapter to connect my new head unit to the stock wiring harness, just wondering if that true and if so where can a guy get one. Truck is a 2003 gmc Sierra head unit is a pioneer avh p6300bt, thanks!

 

I don't think you will. The reason why not is because you have no use for the stock wiring harness - I think. Won't you be running your own wires from the HU to the amps, then from the amps to the new speakers? Okay so that that's the entrire chain, where do the stock wires come into play?

 

Ahh ya gotcha, that's what I'm doing power to amps all speakers run to them just RCA cables from HU. What about the power for the headunit tho? Can I just splice into any keyed on power source? Or just pull the power wire from the stock wiring harness?