2 channel amp for 4 speakers?

[thewishkah]

Hey guys whats up? I have a Rockford p3002 amp thats 75x2 at 4ohms or 150x2@2ohms. I used to use this as my sub amp, but i since replaced with more power and I was thinking of using this amp for my speakers. I have Alpine type S coaxial speakers in my truck now would this be a bad idea? how do I wire the speakers to be 4 ohms? so that i give it 75x2 (I have 4 year replacment on speakers so I dont care If I blow them). Is this possible or a bad idea? I just want more power to my speakers with out having to buy another amp. Thanks for the help, Jon

p.s. I edited because I made a typo i need to wire it to 4 ohms not 2 ohms I want to run 75w rms not 150.

 

[Jason94sport]

If the amp is 2 omh stable, Wire all 4 speakers in series. + of each speaker to + of each speaker then the + of the amp. - the same way - to - then to the - of the amp.

 

[thewishkah]

Here is all the info on the amp, » 2-channel car amplifier
» 75 watts RMS x 2 at 4 ohms (150 watts RMS x 2 at 2 ohms)
» 300 watts RMS x 1 bridged output at 4 ohms (4-ohm stable in bridged mode)
» variable high- and low-pass crossovers (40-400 Hz at 12 dB/octave)
» variable Punch Bass (0-18 dB boost at 45 Hz) with wired remote
» Tri-way capable (Tri-Way Crossover required)
» MOSFET power supply and output devices
» CEA-2006 compliant
» preamp-level inputs

tell me the best set up according to this info please, you said to wire them in series which I understand by why not do left front and back and right front and back 1 side to each chanel so I can control the fade and balance? or will this not work? and will the bass boost knob work with the speakers? or is this a bad idea?

 

[Jason94sport]

Yeah right you can do that. That would be best anyway, wire the left to left right to right. Doesn't matter as long as you keep the wiring correct. + to + to + of amp - to - to - of amp.
The controls on the amp will work the same.
The only issues will be heat from the 2 ohm load. Some amps are ok with this some aren't even if they are rated at 2 ohm. That 150X2 will be split into 4 speakers so each speaker should get 37.5 watts.

 

[toypaseo]

If I had that amp, I would wire the left front and left back in parallel, to one channel. The other side in parallel to the other channel. You lose the front to back fading, but you get 75 watts to each speaker.

I have that setup in my other car. Rockford Fosgate Punch 60 powering a pair of Infinity Kappa 4" components, and a pair of Infinity Kappa 6½" coaxials. This setup makes 70 watts per speaker.

 

[toypaseo]

tell me the best set up according to this info please, you said to wire them in series which I understand by why not do left front and back and right front and back 1 side to each chanel so I can control the fade and balance? or will this not work? and will the bass boost knob work with the speakers? or is this a bad idea?

You will lose the front to rear fading.

If you wired as mentioned above, you would get an 8 ohm load, so each speaker might be getting around 18.75 watts.

 

[thewishkah]

Ok so I get the speaker to the amp wiring which should emliminate the speaker harness to the back of the radio, now which RCAs on my radio do these go to I have a set of rca's that my sub amp is pluged into and then 2 more sets( one staionary and one that is wires coming off the back of the radio). I have a pioneer 7600 and i would assume I connect the remote wire to the same remote wire the sub amp is conected to? Will this help in speaker clarity as well as volume? I am like I said running alpine type s speakers. Thanks for all the help so far, Jon

 

[thewishkah]

Ok so I set it all up and I am having some issues. both amps are powerd and are connected to the remote wire. My problem is the sound quality is horrible my speakers are very low and are very muffled they sound like crap and I cant figure out what i did wrong.
Here is how its wired:
Left front and back are wired to each other and then with just the +/- to the left chanel.

Right front and back are wired the same set up to the right chanel. the left to right balance works so I know they are set up right.

Now as I mentioned in my last post I have 3 sets of RCA's on the back of my radio, they are s/w, F, and rear pre out. I tried it on all 3 of these set ups on
rear s/w and rear full, and on pre out full and pre out s/w and nothing sounds better? I used a dual amp wiring kit if with "power distubution block" its basically just a power spliter from 1 power to 2 powers. I grounded it well so I do not think this is the problem guys I REALLY need some help on this as I need to use the car in a little bit. Thanks in advance, Jon

 

[toypaseo]

Did you switch the crossover on the amp?

 

[JasonF]

Why not just try hooking up your front speakers to the amp normally and run the rear speakers off the head unit? The front speakers do most of the work and the rears are just for fill. This way you wont lose fading and you can test it out with none of this parallel wiring business.

Jason

 

[thewishkah]

lol it was the dumbest thing it was the crossover on the amp lol I figured it out around 7pm after I had ripped it all apart for the second time. Thanks for all the help. Sounds great even with all the agrevation it was well worth it.

 

[expo5.0]

I would run the front speakers off the amp and the remove the rear or run them off the rear channels of the hu amp

 

[thewishkah]

What would be the benifit of that? It sounds great now that I have it all working properly, I just need to fine tune the amp to get my highs a little bit better but at 1/2 volume its as loud as it was at full before. I used to get it up to 62 now I cant go over 50 with out it being deafining. Thanks for all the help guys, Jon

 

[expo5.0]

just to keep the sound from having an annoying rear bias

it's personaly preference of course

 

[thewishkah]

Ok now im getting an annoying high pitch squeal that gets louder on acceleration? is this a grounding issue? its only noticable at lower volume but I would still like to fix it if possible. Any Ideas? ok thanks for the help, Jon

 

[Jason94sport]

Yeah sounds like alt noise. Check your ground, or play with the wires see if gets better or worse. I had some noise in mine, I had to wire tie some of the wires off the body.