funkdaddysmack

I got ambitious today and decided to install my recently purchased shitty 8" subs (MTX Thunder) and kenwood amp, not sure which model. A friend had the stuff for sale, and I thought I'd help him out.

Anyways, I went and got my wiring kit and all that good stuff and went to town. Install went really smoothly, I was impressed. I ran the power, remote wire, and RCAs back under the carpet (I know I should have done opposite sides, but the RCA have good sheilding on them, and it's only 8ga wire, so I thought I'd be fine.

I made all my connections, and the RCAs were a bit short so I had to ghetto-rig the amp location while I went to get some extensions. I had it hooked up, and it sounded really not bad for two crappy subs, oh so pleased was I!

Anyways, I went to walmart and lowes and came back. I hooked up the new wires and attached the amp to the back of the box for easy access (to theives, hahaha). And grounded the amp to the bolts that hold the back rest of the seat on. All the wires were still hooked up, but now I don't get any sound from my speakers. The light on the amp comes on, so it's getting power, but the speakers won't go. I gave up on it for the night, I'll work on it again tomorrow, just wanted some insight to what it could be. Thanks guys!

Sir Nuke

you need to use some standart troubleshooting techniques....first you need to thing about EVERY change you made from the original setup that WORKED...to now....and eliminate each and every change...

did you change the ground? did you change the speaker wires? how about the EXTENSIONS you got.....

you could always try moving it back to the original set up/location and see if it still works....if so....there is some flaw in the new location/wiring.

hook it back up the original working way, still work? IF NO, disconnect the subs and get an OLD speaker just laying around and hook it up, maybe the subs just died or something came loose in the box,

if YES....then just add the RCA's,....still works? fine, turn it off and move it to the NEW location......if NO...you got a bad extension.

Now you are in the new location....hook it up again, does it work now? YES, you are in business, if NO then I would say it MAY be the speaker wires.....OR the ground.......

OF COURSE there is the worst case.....the amp just died all together.



OR WORST CASE....the amp just died.

funkdaddysmack

Well, I got confused because I didn't have to unhook any wire (other than the RCAs) to move it to the new location. I already squeezed another foot out of the RCAs so now they are going directly into the amp, so it's not an issue of the new RCAs. So in theory, the only thing I changed from the two locations was the ground, and since the amp 'powers on' (I see the light on), it doesn't seems to be a ground issue. I want to go out and check it out now, but it's hardly ideal to be messing with it at night on the street.

I have no luck with amps!

Sir Nuke

its POSSIBLE that the new ground location is enough to power up the light...but a poor gound MAY cause the amp to not funciton properly.....give it a shot.....

funkdaddysmack

Thanks Nuke, I appreciate your help. It also makes me feel better I'm not the only one cruising the boards on a Sat. night... hahahha

Sir Nuke

If I had a choice...I wouldn't be....but I am at work.....lol

1st MP3 in NH

Don't worry about that my sorry *** is always here.

A few things could be wrong.
If you have the light on the amp then you have power but it may be to little to ruin the amp. Make sure all connections are good.
I don't hink this is your problem.

If the RCA was stretched then you may have broken it inside this will stop signal from getting to the amp. Run another over the carpet just to test and see if that fixes it.

Most Kenwoods have external fuses on them. If its blown you won't get ****. This fuse if for the speaker wires if they touch it will blow. Make sure the leads are on the sub real good.

DO you have a multimeter or an ohm meter?
Make sure you not seeing a voltage drop across the fuse under the hood. THis has got me twice now. I had a POS Saab with this issue amp was on but no sound. the fuse had oil on it and was causing a 7 volt drop across it. The amp only read 5 volts across power and ground.

Make sure you didn't set the amp high pass accidently, should be low pass, sorry if you know crossover but I get tons of amps in to check out and everytime the little knucklhead that owns it never used the crossover for the sub amp.

All power and ground wires should be 8 guage, no less on power or ground. I know you said you extended so make sure you don't have a voltage drop on either wire.

I doubt the amps is dead unless the subs were wired at a lower impedance then the amp could handle.

Sir Nuke

even though you said it WAS working.....make sure the gain is to where you are getting a signal...

the VERY first time I turned on my system I got NOTHING out of my sub....but did all the doors....I KNEW something was up....and this being my first amp install I had to think a bit....then realized there was a gain adjustment for the sub too....tweeked the **** and presto chango....there was THUMPIN going on! lol

funkdaddysmack

Thanks for the responses guys. I'm guessing that my ground is the culprit, I'm going to be out there first thing (or as soon as I get my lazy *** out of bed) tomorrow. I've checked all my fuses, even the one on the amp, so I'm good to go there. I hadn't though about if it were the RCAs, that's a definate possibility. I may go to walmart tomorrow and pick up a spare set if the ground thing doesn't come through.

This too was my first amp install on one of my vehicles. I was pleasently surprised at how well I did (i'm notorious for getting boned over on everything I do) even if it's not working right now. All will be well! I'll let you know what happens tomorrow.

hihoslva

Hey, if you "stretched" the RCAs with a few tugs, is it possible you yanked them loose from behind the deck?

Gotta check everything, you know. Start with fuses, then connections, crossovers, gains, settings, etc. If nothing works, then it's time to start pulling things apart, unfortunately.

Behind the deck is just another place to look - see if the RCA's got pulled out. And as stated earlier, you *might* have damaged the RCAs by yanking on them (if you did pull like that) - especially if they are el-cheapo cables. YOu may be able to see behind the deck without pulling it out - remove your glovebox and get up in there with a flashlight and see if everything checks out.

Good luck - let us know what happens.

~HH

funkdaddysmack

Update for those who care:

Went out for about 2 hours earlier today to try and make some sense of the situation. Cliffnote version: something probably wrong with amp.

Step 1: First of all, I took the amp off the back of the box so I could hook it up where I had it ghetto-rigged yesterday (when it worked). I got the ground good and hooked up, amp powers on, still no sound.

Step 2: I pulled out my deck to see if the RCAs came out of the back of the deck, but they were still in there. Out of curiosity, I pulled the RCAs out from under my carpet to see if there were any cuts or breaks, etc. in the line, all appeared to be fine.

Step 3: Maybe the subs got disconnected in the box? Nope, I hooked them up to the rear channel from my deck, and got sound from them.

I checked and double-checked all the settings on the amp, setup for the right input, right crossover settings, etc. In fact, i didn't touch anything on it since I got it working yesterday. The HU still had the rear outputs enabled, so it wasn't a problem with the HU.

I swear, nothing can ever go right for me, not even a simple freaking amp install. This is why I get pissed at my car and don't want to do anything to it. I'm going to have my friend who's an electronics major to take a look at the amp for me I think to see if he can get anything to fly. I suppose I could pick up another set of RCAs, but the other ones looked perfectly fine to me. So for now I'm going to just not care about it I guess. Thanks for all the help guys.

1st MP3 in NH

WHat is the amp and the subs impedance, each and total? HOw did you wire the box.

You said you pulled on the RCA's to stretch them. If you did this you probably ripped then internally. Also a large voltage drop any where can cause this problem.

funkdaddysmack

Well, I don't really know much about car audio so I can't answer your first question. The RCAs are clear, and I can't *see* any rips, but I may get another pair just to be safe.

Actually, I just went out to my car and got the RCAs, and they work fine (at least on my stereo and tv in here). SO, moral of the story... Gotta be the ******* amp... Chalk one more non-working amp up for me!

hihoslva

Dude - the first question is the most important!!!

The impedance (ohms) of a sub is what determines the power you will get from the amp - and when wiring two or more together, it's VERY important to know the impedance of each, and the total impedance the amp "sees". Too much, crappy power. Too little, amp fries. And the documentation with your amp will tell you what load it can safely handle.

Example:

Pair of 4 ohm subs, wired in series (subs connected one to another, and to amp bridged mono) is an 8 ohm load to the amp. If the amp is rated to handle no less than 4 ohms when running mono (most two channel amps are like this), at 8 ohms, it'll only put out half-power.

Same pair of 4 ohm subs, wired parallel (subs connected to amp independently - basically, two sets of + and - wires from the same terminals on the amp, one set to each sub - NOT one sub per channel, but two subs on the mono, bridged channel) is a 2 ohm load on the amp. If the amp is rated to handle no less than 4 ohms when running mono, the amp now puts out double power, but only for a short time, and then fries from overheating.

Makes all the difference in the world. See what's up with your amp - then ask around about this stuff before your next install (or re-install). We'll help you avoid this kind of disappointment.

~HH

1st MP3 in NH

DO you have a 2 channel amp or a mono. What are the subs 4 or 8 ohms? If you try to run a low impedance load off of a kenwood 2 channel it won't play and if it does it cooks quickly.
Disconenct the subs from the amp and just put any old speaker, even home on the amp and see if it works.