Power to Amp? Check, Subs? Failed

[Deez54]

I've got a Soundqubed Q1-1200D amp powering two Sundown SD2 10's. Before I hooked these up I had everything pre-wired to a different amp and subs and everything was working fine.

The subs are running in parallel and there is power to the amp, but I am getting zero response out of the subs.

I'm sure this problem is frequent and I tried searching for solutions, but nothing useful really came up. Can you guys help me trouble shoot this problem?

I've tried swapping the RCA connections to see if that was the problem - nope. Tried wiring the subs a different way - nope...

Appreciate it

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[mlstrass 5,000+ posts]

make sure switch is set to Master...first thing I'd check if amp is powering on but has no output

 

[Deez54]

I have no idea how this is possible, but the RCA output of the head unit is pretty weak/bad.

 

[CSCStang]

To rule out the Hu and/or rca's, plug an ipod directly into the amp using a 3.5mm to rca cable. Also, if you have 2 d2 subs wired parallel through, you are running that at .5 ohm. Is that amp stable at .5?

 

[csu87 10+ year member]

try a new set of RCAs. Ive had this type of issue when i swapped out amps before. RCAs worked before the swap, but after, wouldnt work with the amp

 

[Deez54]

They are D4's, so it's running at 1 ohm. I plugged in my RCA cable into a different head unit and it boosted the output of my subs DRAMATICALLY. It can be so low when my head unit is plugged into the RCA's that you can hardly tell they are on unless it's turned way up with the gains and bass boost cranked, then I plugged them into another one and BOOM! Seriously crazy.

I'm not sure how this happened though because I had the same exact set up (wiring) minus the DVC's and it sounded pretty good. I just upgraded my sub and amp. (went from two 150 RMS subs/500RMS amp to two 500RMSsubs/1200RMS amp).

What could have caused this?

 

[Deez54]

To rule out the Hu and/or rca's, plug an ipod directly into the amp using a 3.5mm to rca cable. Also, if you have 2 d2 subs wired parallel through, you are running that at .5 ohm. Is that amp stable at .5?

try a new set of RCAs. Ive had this type of issue when i swapped out amps before. RCAs worked before the swap, but after, wouldnt work with the amp

They are D4's, so it's running at 1 ohm. I plugged in my RCA cable into a different head unit and it boosted the output of my subs DRAMATICALLY. It can be so low when my head unit is plugged into the RCA's that you can hardly tell they are on unless it's turned way up with the gains and bass boost cranked, then I plugged them into another one and BOOM! Seriously crazy.

I'm not sure how this happened though because I had the same exact set up (wiring) minus the DVC's and it sounded pretty good. I just upgraded my sub and amp. (went from two 150 RMS subs/500RMS amp to two 500RMSsubs/1200RMS amp).

What could have caused this?

 

[CSCStang]

Ok. The op you wrote said d2. You could have a bad Hu then bro. Test your rca pre outs with a dmm.

 

[azmcrae 10+ year member]

What brand / model headunit do you have?

 

[Deez54]

Ok. The op you wrote said d2. You could have a bad Hu then bro. Test your rca pre outs with a dmm.

SD2 10's are Sundowns shallow mount subs. It's the model not the impedence. What is a dmm?

azmcrae, I have a Pioneer HU. Model escapes me atm. It's pretty outdated - about 3-5 years old maybe.

 

[CSCStang]

One thing I've learned about Pioneer decks is you don't ever swap out rca's (or plug and unplug them into an amp) while the stereo is on. You can blow a Pico fuse very easily (they are internal). A dmm is a multi meter. You set it to AC to test the voltage coming out of you pre outs. If there's no reading, it could be you blew a pico. Why not use the other head unit you tested?

 

[Deez54]

One thing I've learned about Pioneer decks is you don't ever swap out rca's (or plug and unplug them into an amp) while the stereo is on. You can blow a Pico fuse very easily (they are internal). A dmm is a multi meter. You set it to AC to test the voltage coming out of you pre outs. If there's no reading, it could be you blew a pico. Why not use the other head unit you tested?

Cause it's not mine. And if the fuse blew there would be no current right? so there wouldn't be any signal coming from them at all, but there is. It's just pretty weak.

 

[los33]

Cause it's not mine. And if the fuse blew there would be no current right? so there wouldn't be any signal coming from them at all, but there is. It's just pretty weak.

If the pico fuse blew you would hear some type of buzzing or weird noise coming out since the rca's would sorta burn due to pico fuse.

Have you tested the voice coils with a dmm?

 

[Deez54]

Have you tested the voice coils with a dmm?

I did. Everything checked out just fine from the amp on. I don't know how or what happened, but the head unit just doesn't send out a good enough signal via RCA's.

The kicker here is, the other head unit I used was the exact same model and had the same exact settings (flat all around), and the sound was twice as good with the other unit.

 

[CSCStang]

Time for a new hu bro.