Coolsaber57

iTrader: (22)

Hi guys,

My first post in the audio section here, so go easy.

Let me begin by saying that I'm definitely not a guru, nor am I a complete noob. I have experience with a lot of electronics, audio and otherwise, but this is my first subwoofer install.

Here's the situation:
1. I had an old sub/amp combo in my old car. Kenwood 600w max amp, and Sony xplod 1200w max subs (2) mounted in a huge ported box. Worked fine in that car.

2. I don't like that much bass, so I took the subs out, got a new single box, and installed one of the subs in the box.

3. Ran power (4gauge) and remote wire along left side of car

4. Ran audio cables down right side of car. They connect to a JVC KD-DV5100 headunit to its "Line out"

5. Connected everything in the trunk, but have no sound whatsoever.

6. Got out the trusty multimeter and found that the power is fine ~12v.


What should my next steps be? How should I test the signal coming from the headunit? Is there a way to test the cables w/out taking them out of the car? (It is a b!tch to redo the wiring)

Thanks!

AscendantMax

iTrader: (7)

is the remote line getting a 12 volt when the head unit is on?

1996blackmax

iTrader: (2)

Good point...is the amp turning on?


I myself had some issues with my amp. No sound for a couple of weeks, and no time to look into it until this weekend...turned out to be a wiring issue.

Coolsaber57

iTrader: (22)

i'm not sure, How can I test for that? 1 probe on the remote and 1 on the car chassis?

AscendantMax

iTrader: (7)

pretty much. postive lead on the remote wire, and just ground the negative somewhere on your car. have the head unit on. it should read 12 volts.

Coolsaber57

iTrader: (22)

I was under the impression that the remote wire only sent power once, when the headunit starts up. Not true? It's on all the time?

1996blackmax

iTrader: (2)

Yes, the whole time the HU is on.

Coolsaber57

iTrader: (22)

Hmm, I will try tonight. What about the audio signal? how do I test for that? I'm just trying to eliminate as many factors as I can

AscendantMax

iTrader: (7)

might be a little harder to test for the audio signal. but you can test it with the multimeter as well. just touch one lead to the protruding prong and one lead to the 'brim' on the rca's. you should see some voltage.

but check the remote line first.

Coolsaber57

iTrader: (22)

Interesting. What about the sub, could I test the sub with the multimeter? I was researching online and someone suggested trying to use a battery, but I couldn't get it to work. Ideas on that?

AscendantMax

iTrader: (7)

you can. set the multimeter to read resistance. then put the leads onto the speaker terminal of the box. depending on the sub's coil configuration...you'll see a resistance.

the battery just makes the sub pop in our out. take the speaker wire from the box, and hold one end to the negative side, and tap the posititve side with the other wire. you should see your sub move.

spark plugs.

iTrader: (3)

set the multi to ac volt., connect the probes to the amp outputs, check to make sure that you're atleast getting like 15volts outta the amp to make sure the amp is trying to put something out.

AscendantMax

iTrader: (7)

the amp gotta turn on first to do that.

Coolsaber57

iTrader: (22)

Great! Thanks man, I will try all that tonight when I get home

Coolsaber57

iTrader: (22)

AC Volts? Isn't it DC power?

Ok, here's an update: the remote wire is giving power to the amp. Not a lot though, like 1.5v. For the "ground" I used the ground that was connected to the amp (i just put the probe on the ground terminal w/ the ground wire plugged in) Are you sure it's supposed to be 12v?

The sub is reading 4 ohms though, which is good.

I'm also thinking that my battery may be on its way out, because I tested the regular power again, and it was only about 8.5v and dropping. I accidentally left my lights on the other day and drained the battery completely (though it was only like 2hrs..) but was jumped and then drove for like 30 min back home.

Why would the remote wire only read 1.5v? I tapped the remote wire coming from the headunit...what else was I supposed to do for that?

AnDyMaN

iTrader: (19)

I would guess the remote wire puts out very little volts because it doesn't need to be high. just a signal that tells the amp that the HU is turned on. On my car, im using the thinnest wire i could find, probably 22 gauge or higher.

I would check and recheck the ground wire. This is a big reason for a lot of installs to not turn out right. I had problems for a while, and it turned out the ground wasn't as solid as i thought. Gave it a wiggle, tightened it, and it has worked since.

If everything is fine, but you have no sound, i'd put my money on the ground.

AscendantMax

iTrader: (7)

nope. the voltage gotta be way higher for the remote wire....

what wire did you tap the remote into on the head unit?

Coolsaber57

iTrader: (22)

The remote wire. It's a blue wire with a white stripe on it for the JVC KD-DV5100

I just assumed that that was the correct wire, since it's the only remote wire...

Andyman, I will redo the ground. Where do you guys have your ground goin to? The only bolts that I can see are the strut mount ones...do you guys use those?

AscendantMax

iTrader: (7)

hmm, you should be getting 12 volts then. how did you connect it?

Coolsaber57

iTrader: (22)

I stripped the blue/white wire at a point that is about 3in away from the actual HU. Then I stripped the end of my remote wire (radioshack brand - 18 or 22 gauge). Wrapped the exposed end around the stipped part of the remote wire, then taped it all up.

nismos14

iTrader: (56)

Did you adjust the gain on the amp at all? Are you sure it isn't turning on? Are your rca's connected? lol.

Coolsaber57

iTrader: (22)

Yeah, everything was connected, and I messed w/ the gain, but to no effect, that's what started this whole process.

I've narrowed it down to :
-battery (it's leaking acid...I think it might need replacing)
-amp - worked in other car, but that was a few months ago
-remote wiring - not enough power? After battery replacement, I should know more
-Ground - I'm gonna redo the ground wiring and put it under one of the strut mount bolts (or whatever they're called)
-RCA cables - I tested these before...but maybe they got messed up somehow.
-Lastly, the HU - May not be putting out signal through the line-out

Oy..this should have been an easy process.

AscendantMax

iTrader: (7)

is the amp turning on? (such as a LED lighting up etc)

Coolsaber57

iTrader: (22)

Negative. I read that that means the "protective circuit" is activated, and gives a few suggestions about that.

I was looking through the specs and found something. The sub is a 12" 1200w max, 350w RMS Sony Xplod. However, the Kenwood KAC-728S is 600w max, and 300w RMS (bridged).

I know that underpowering a sub can cause damage to it, but is that what it means to be under-powered? Will that damage the sub? It's not the issue right now, as the issue is with the amplifier/power source, but I'd like to know if I should be looking for a diff. sub.

nismos14

iTrader: (56)

Under powering won't damage the sub, unless you are running your amp into clipping and sending that signal into the sub.

Also don't read much into peak numbers, the rms is what you should be looking at and 350 rms sub with 300 rms from the amp is more than sufficient.

AscendantMax

iTrader: (7)

i still think it's the remote wire. the HU isn't giving the right amount of voltage for the amp to turn on. you can try this...take a small wire and run it from the power wire to the remote input on the amp. the amp SHOULD turn on. if it does, then there's something wrong with the HU.

Coolsaber57

iTrader: (22)

Isn't that way too much current for that and cause damage?

Also, what is clipping?

nismos14

iTrader: (56)

No it's not too much current.

Coolsaber57

iTrader: (22)

Word, I will try that as soon as I can. Dang work and its getting-in-my-way-of-fixing-the-car

What's clipping BTW?

AscendantMax

iTrader: (7)

http://www.bcae1.com/2ltlpwr.htm

daesonn

I currently have the same problem in my car, except the remote wire when tested was giving more like 0.04v or so while the headunit was on, making me think theres deffinately a problem with it. The only weird part is that halfway through the install, to test we plugged my sub into a 4 channel amp with the midbass installed as well, and they both worked fine. Continued with the install (installed a dash kit, hooked up my second single channel amp, finished all wiring) and now my amps aren't outputting. I've tested for power, and the power and ground are putting out fine, its just that damn remote. I really wish I didn't have to take apart my main console again, thats a *****, and the reason my car has no sound right now

Romster

iTrader: (1)

Make sure you have solid wire connections - don't just twist them together and tape, use crimp connectors or solder.

You said the amp gets power, so that leaves the remote wire, ground, and RCA's. Good Luck

Coolsaber57

iTrader: (22)

Update:

FIXED!!!!

Ok, well, my battery did need replacing. After that, I re-did the ground, hooked everything up, and it worked fine....

Thanks to everyone for your help!

Check the connection to the remote wire, as well as the one to the amp.

After that, check the battery...that's what my problem seems to have been. (that and/or the ground wire)

daesonn

I'm pretty sure my ground is fine because when we used the voltometer with one side on the ground and one on the power it showed it was fine, that means it has to be the remote right?

Coolsaber57

iTrader: (22)

Definitely check the voltage on the remote wire again after rechecking the ground, then see if it's your battery.