dual subs with dual mono amps

[zonecode88 10+ year member]

Hello, I recently picked up two Alpine SWX-1042D subs and two Kenwood KAC-9152D mono amps. I wired everything up and installed it, but I'm not having the expected performance from my system. I'm using a sealed box, and each sub has its own seperate air space inside the box. The problem is that I don't think my amps are putting out the right amount of power. The amps come with remote bass boost knobs, and I discovered something weird when playing with the knobs. I can turn one all the way down, and the other one half way up, and the bass pumps loud, but when I turn the boost knob that was at zero up at all, the bass actually decreases. So I disconnected one amp and I can actually get better bass from running just sub with one amp. My guess is I'm having power issues, like maybe there's not enough current flowing through the amps when they both are on. Possibly I need better grounds? I'm running 2 gauge wires from the batter to the cap, and from the cap to the dist. block. From the dist block im running 4 gauge wires. (2 gauge ground on cap and 4 gauge grounds from amps). I appreciate any help or ideas, thanks.

-Zonecode88

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[johnson 10+ year member]

Check the wiring on your speakers to see if one is out of phase, meaning the polarity is reversed.

 

[djman37 5,000+ posts]

x2, sounds like 1 is out of phase with the other.

 

[zonecode88 10+ year member]

Each amp has a phase switch on it. THe switch can either be at 0 or 180.... which settings should I use? Thanks for the quick replies fellas.

 

[unbonyr 10+ year member]

I'm guessing those kenwoods put out there respective watts at 1 ohm and since those subs are dual 4 ohm each sub is wiring down to 2 ohm on each amp that means the amps are only putting out what they do at 2 ohm not 1. So my suggestion is sell both those amps and get one that puts 2000rms at 1 ohm not 2 seperate ones.

 

[djman37 5,000+ posts]

Each amp has a phase switch on it. THe switch can either be at 0 or 180.... which settings should I use? Thanks for the quick replies fellas.

if everything is wired correctly, the amps should be identical...gains, settings, etc.

to TEST, flip 1 of the phase switches.

 

[djman37 5,000+ posts]

I'm guessing those kenwoods put out there respective watts at 1 ohm and since those subs are dual 4 ohm each sub is wiring down to 2 ohm on each amp that means the amps are only putting out what they do at 2 ohm not 1. So my suggestion is sell both those amps and get one that puts 2000rms at 1 ohm not 2 seperate ones.

read the original post, and look for solutions to the problem he is describing.

1 amp wouldn't have fixed the fact he has, most likely, a sub wired wrong.

 

[zonecode88 10+ year member]

The specs on my amp gave 900watts RMS at both 1 ohms and at 2 ohms. Gains are identical also. The subs are DVS4+4, and I have them wired in parallel, accepting a 2ohm load. The subs are 500-100RMS. You don't think an inefficient ground could be my problem? I really am not interested in selling these amps, rather in getting everything I have now to work correctly. Thanks again.

 

[zonecode88 10+ year member]

Thanks DJ. I suppose I will go re-inspect my wiring and see what I come up with. I'll post what I find.

edit: A side note is that there isn't one sub that works better than the other, just I can only get one of them at a time to bump loud like the way it should. And this is with identical settings on both amps.

 

[zonecode88 10+ year member]

Wow, guys, go ahead and call the idiot police to come and arrest me. Johnson and dj, you guys were exactly right. I had one of the speakers wired in backwards polarity. Sounds good now. I can now listen at loud volume from both speakers now. Thanks again.

 

[johnson 10+ year member]

Glad the problem was fixed.