I recently changed head units and now it seems that my subwoofer is not working.

The only problem is I'm not sure if the sub stopped working immediately after the new HU install. I've been racking my brain trying to remember, and I think I remember the sub working fine with the new HU. Then a few days later I noticed that there was no sound coming from the sub.

I have a JVC AR 8000 or 9000 series, not sure right now of the exact model, but there is are designated out put cables for the subwoofer and and for line in. I plugged the rca cables from my amp into the ones labeled subwoofer. There are also some out put plugs on the back of the HU, this is how I had my sub setup on my last HU, so I tried those also and it still didn't work.

I am getting power to the amp, I checked the fuses and the amp light is on.
Is there a way to check the subwoofer without taking it out of the box?

I don't think I blew up the sub, I don't really ever crank it up.
I checked the install of the HU and everything works fine except the sub.

Not sure if the install details will help, but from the back of the HU I have the RCA cables plugged into some cables labeled "subwoofer" then to the amp,amp has power wired to it, sub speaker wires are connected to the amp.

 

rob,

so as i undestand it, it worked, but then one day, it didnt?

good you are troubleshooting the wiring, but most if not all headunit these days seem to have some kind of on/off setting at the HU level where you can control the output to the subs. i have an alpine and i have the ability to completely shut off the subs by the headunit.

bob

 

Yes, I believe it was working fine once I finished the initial install.
I did look for some of the subwoofer controls on the headunit, but did'nt find much besides some eq settings I'll have to go back and read some more of the guide to see if there are any others I'm missing

 

rob,

when i recently put in my sub, there was no sound coming out of it. i was pulling my hair out trying to retrace everything and everything was just fine. then i RTFM'd and then began to slap myself silly because it was a press of a few buttons and voila, bass.

hopefully it will be that easy for you too

bob

 

What kind of amp? Are there any other EQ's, crossovers, etc in the system?

Have to take a methodical approach with these thngs...

Push in the speaker gently. It should move smoothly. If there's any grating, the speaker is probably fried.

Unhook the speaker wire leaving the amp. "Pop" the speaker by touching the ends of the speaker wire to a battery (preferably something like a cordless drill battery). The speaker should move and make a "pop".

Check the amp for output. You can hook up another speaker if you have one, or check for AC voltage across the speaker terminal (easiest if you have a test tone, otherwise use radio static)

Check the RCA's coming into the amp - unplug them and check for AC voltage between the shield and the center pin using a test tone or radio static.

That will narrow down where in the chain it's going bad, then start looking.

If it shows as the head unit, some things to check:
- on some head units, the subwoofer output RCA's can be configured as an aux input
- if it has built in crossover, make sure there's no conflict (should be on LOW PASS)
- make sure subwoofer is selected "yes"
- make sure subwoofer level is >0

Also:
- check amp gain level. If you went from a very high input level (say speaker line) to a low level RCA, the gain may be too low for you to hear output

Try those, let us know what you find and we'll go from there

 

This is probably not the problem you are having, but I'll toss in my 2 pennies:

Working with an Audison LRX 1.400 and that sucker wouldn't play. It would turn on, but there was never any output. Found out that we had to install a relay so there would be enough juice to actually switch the amp on. Sent back another amp the previous day because i thought it was broken

 

Please tell us your exact model #.
You should have the ability to set the the subwoofer cut-off frequency level (55Hz,85Hz,or 115Hz) and the subwoofer output level (0min-8max).
If you have RCA sub outputs on your HU you will have a way to adjust the levels on the HU.

 

Ok, It's the KD-AR960 by JVC. And you're right there are some subwoofer controls for frequency level (55Hz,85Hz,or 115Hz) and the subwoofer output level (0min-8max).

I didn't do anything with these, what should I set them at? I hope this is the only problem. Thanks!!

 

Choose 115 Hz and 4-6 on the level for testing the sub. Once you are sure it is working, you will probably want to lower the crossover to reduce the overlap with your main speakers. Also the higher frequencies through the sub will make it more noticeable that the bass is coming from behind you.

 

***Update***

We have Bass!!

Thanks to everyone for their suggestions! I finally got some time to get out there and look for the things you guys mentioned. Started by checking my speaker on my brothers system, and it worked fine. Then I checked for AC voltage across the speaker terminal, Bingo!

It worked before on my old H/U the way it was setup, but not with this one, anyone think of why not? The way it was setup was as "bridgable" and now I had to set it up as the Right side output to get it to work.

Anyway, I'm just glad to have my sub working now, Thanks again for the help.

 

Ok, now I have bass, but it seems like since I only have it setup on the right speaker output of the amp I'm missing some sound.Like if the beat changes to the left speaker or something I only hear it through the front speakers. It seems like the subwoofer isn't getting the complete signal.

Is there a way to fix this?

 

Is there a switch on your amp for mono?

 

Not that I know of, but I'll check it out later today. If it is there what should it be set to?
This is getting frustrating, it was sooo easy to setup on my old h/u and now with this new one I thought it would be even easier since it had the "subwoofer" labeled outputs.

 

if it does...set it from "stereo" to "mono" sounds like it is in stereo right now

 

It was set to mono, but I think I have it wired correctly now. Although I don't understand why it works now. I'll have to take a pic of the speaker outputs on the amp so you can understand what I'm talking about though.

The first time I got it to work I had it wired to the right speaker output (+ and -) Now the only other outputs I could get a reading from were both labeled neg(-) so I wired it and it works!?? So far, It doesn't cut out like it did when wired right side only.
Oh well...

 

this is what had happened to my speakers. i had taken them out and put them back in so i could clean my truck out.. well i had my 2 wires going to the input and output were in the output ports... they should have gone to the input ports, then i had my negative wires going to the positives on my subs and the positives on my amp going to the negatives on the subs. you should try this... my amp is a audiobanhn 2000 watt amp powering 2 anniversary edition 12s dual voice 4 ohm with 1200 rms.. i have them both bridged.. they sound pretty good... but i want to get 2 L7 15s 4ohm.. but they would take up my entire backseat... oh well..

 

GET TWO WIRES AND PLACE ONE IN EACH TERMINAL HOLE OUTSIDE THE BOX WHERE YOU NORMALLY HOOK UP THE SPEAKER WIRE. TAKE ONE OF THE WIRES AND HOLD IT TO THE NEGATIVE POST ON THE 9V BATTERY THEN TOUCH THE OTHER WIRE TO THE POSITIVE AND SEE IF THE SPEAKER MOVES IF NOT THEN IT IS INDEED BUSTED. JUST DONT HOLD BOTH WIRES TO THE BATTERY. HOPE I WAS HELPFUL.