Questions about 4ch amp routing

[CadillacMatt 10+ year member]

Hey everyone, I was wondering if I could get some advice on how to wire a new Infinity Reference 475a 4channel amp to my 4 interior speakers in my '95 Cadillac Sedan Deville.

I currently have two amps (RF Punch 325.1 & RF P3002) pushing my two Sony Xplods in the trunk. I have a Pioneer DEH-P4000UB head unit running the system. In my kick panels are a pair of Kenwood 6 1/2 speakers, and the rear deck seats two RF Punch 6x9s.

My question is how would I go about running the Infinity? I know I'll have to route another power wire and a remote wire... but as for the speakers, how would you do this? I was thinking of splicing the positive/negative for each wire off at the back of the head unit and routing it to the amp as a line level input, then running it back. Seems kinda repetitive, though, a lot of wires going back and forth...//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

And as far as the RCA inputs go, would I just run another set back from the Infinity and split it between the two amps in the back?

I'm so confused... Is there an easier way to do this that I'm overlooking? Thanks for your help!

Click to read more...

 

[ultimate157 5,000+ posts]

First, run both subs off of just the 325.1

Take the power wire you had on the 300.2 and use that for the new amp.

I assume the amp is going in the trunk, therefore just run the rear speaker wires right up to the 6x9's.

Now for the hard part. Run two new wires from the trunk directly to the front left and front right speakers, don't go to the HU because that will be redundant, time consuming, and totally not worth it.

 

[CadillacMatt 10+ year member]

Ok cool, thanks for the reply... now when you say run both subs off of the 325.1 do you mean to bridge them in series or parallel?

 

[ultimate157 5,000+ posts]

Ok cool, thanks for the reply... now when you say run both subs off of the 325.1 do you mean to bridge them in series or parallel?

Depends on the specs on the subs and amp.

Are they DVC, SVC? What impedance?

Specs on the amp?

 

[romans535 10+ year member]

Depends on the specs on the subs and amp.
Are they DVC, SVC? What impedance?

Specs on the amp?

One of these days I'm gonna think of a question you might not know the answer too.//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif DAM your like a car audio wizard. write a book and I'll buy it:laugh:

 

[CadillacMatt 10+ year member]

The P325.1 specs:

Mono block (1 channel)

175 watts RMS x 1 at 4 ohms (325 watts RMS x 1 at 2 ohms)

2 ohm stable

The Xplods:

1000w max, 300w RMS

4 ohm SVC

 

[ultimate157 5,000+ posts]

The P325.1 specs:
Mono block (1 channel)

175 watts RMS x 1 at 4 ohms (325 watts RMS x 1 at 2 ohms)

2 ohm stable

The Xplods:

1000w max, 300w RMS

4 ohm SVC

Perfect. Wire them in parallel for a 2 ohm load.

 

[CadillacMatt 10+ year member]

Well I just got back from the car... I didn't try the mono block in series but just parallel instead (I had two wires coming out of each terminal on the amplifier going to their respective sub terminals... is that the correct way to do it?) and it was actually almost as loud as having the two amps hooked up (a little less "full" sounding the bass sounded tighter if that makes sense) but I guess that's the characteristic of the amp itself.

Which brings me to my next question... I had the RCA L/R coming from the head unit split into four ends, and hooked into my amps that way... I recently had a duh moment and realised I wouldn't have to do that if I used the 'pass-thru' port on one of my amps... I tried both ways and I honestly couldn't tell the difference.. so what exactly happens to the sound signal when you split it using a y-harness... does the signal strength split 50/50 between the amps? What about pass-thru... do both amps then get the full signal from the head unit or does the master amp "eat" some of the signal strength?

I think I will try your idea Ultimate when I get the time!

Thanks

 

[ultimate157 5,000+ posts]

Well I just got back from the car... I didn't try the mono block in series but just parallel instead (I had two wires coming out of each terminal on the amplifier going to their respective sub terminals... is that the correct way to do it?) and it was actually almost as loud as having the two amps hooked up (a little less "full" sounding the bass sounded tighter if that makes sense) but I guess that's the characteristic of the amp itself. Wire the subs like this:

Which brings me to my next question... I had the RCA L/R coming from the head unit split into four ends, and hooked into my amps that way... I recently had a duh moment and realised I wouldn't have to do that if I used the 'pass-thru' port on one of my amps... I tried both ways and I honestly couldn't tell the difference.. so what exactly happens to the sound signal when you split it using a y-harness... does the signal strength split 50/50 between the amps?

The signal is split, but its not the voltage that changes, but the current. The voltage is what matters when supplying an amplifier with an input signal. That is why the sound doesn't change.

What about pass-thru... do both amps then get the full signal from the head unit or does the master amp "eat" some of the signal strength?

The pass through is more than likely a direct connection to the input circuit, which is the same principle as the Y-split explanation above.

I think I will try your idea Ultimate when I get the time!

Thanks

..

 

[CadillacMatt 10+ year member]

Ok... I just wired everything like you told me ultimate... I am running the subs in parallel on the P325.1 mono block and I wired the four interior speakers to the Infinity 475a.

However I think I might have some crossed wires (scratch that... I KNOW something's crossed) because when I turn on the system, first of all it pops loudly when I push a button or turn it on.. secondly the front two speakers hiss constantly and the fader/balance controls have no effect on the sound. When I turn it up just a little the speakers start to bang and pop loudly as if they were being fed monster bass... no music can be heard... //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

I have the Infinity amp being fed through the Fosgate pass-thru... all of the crossovers for front/rear on the Infinity are set high, the filters are set on high-pass, the input levels have been checked and are having no effect.

I'm packing it up for tonight and going to take a fresh look at it tomorrow. I suspect the old factory speaker wires that I pulled off the front right door speaker might be touching, because I don't remember taping them up. The other three are not touching I made sure of this. So if you have any insight into what I else I might check or might be overlooking I would greatly appreciate it... or if you need any more information let me know. Thanks!