Little/no output from amp-help please

[ARK_SWAMP_RIDER 10+ year member]

I recently installed a JL amp and sub in my vehicle, and after listening to it a friend of mine decided he wanted a sub setup. The install in my vehicle was my first, I'd watched it done but never tackled it alone. It works great, and I used speaker level inputs on the amp. Since mine went well (much more involved install than his should be), I agreed to help him out with the install. SO, today he purchased a pair of Kenwood 10" subs and a Kenwood amp to power them. We did the install, but there is practically no output from the amp. He has two speakers (6x9's) in the rear deck. We tapped into these speakers, using the same style wire tap I used for my install (exact same product). With everything wired up, you can barely tell the subs are on. I've seen this setup before, and while it isn't the best or most powerful, it'll definitely thump pretty well. So, I need to know what is going on. I have tried the speakers in my vehicle (same wattage, same load at the amp) and they work great. Thinking the amp may be defective, we swapped it for another and still no luck. I know it has to be in the wiring. Thinking we had wires crossed somewhere, we traced them. Everything seemed to be in check. We took the wires and held them in different configurations (using all 4 terminals on one speaker, 2 on the LR speaker and two on the RR speaker, etc), and still got barely audible volume (from the trunk, can't be heard at all in the car. I put a multimeter on it, and the needle won't even budge. I've done every bit of hooking and swapping I can think of. He has a Lexus ES300 with factory radio, so we can't run RCA inputs. The rear speakers we're hooking into aren't factory, but they are working fine. There are a ton of wires, someone seems to have done a poor job with the speaker install. However, since there's signal at the speakers, I just can't figure it out. Can anyone help me with this? It's VERY important that I get this working for him, because we're stuck with the equipment and he's bummed out and counting on me. Here's a pic or two of the rear speaker setup and the wires we're tapping into. Any suggestions? Thanks!

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[kr15 5,000+ posts]

Just out of curiosity did you check the ground?

 

[ARK_SWAMP_RIDER 10+ year member]

No. The amp was powered on, wasn't in protection mode or anything, so I thought the ground would be good. Could that be a potential cause?

 

[Steelers6Time 10+ year member]

Looks like the SS Tarantula 6x9s are BI-ampable and you are tapped into the tweeter input....

 

[Steelers6Time 10+ year member]

should probably tap into the wires BEFORE the x-over, or at least the mid-woofer side.

 

[subzero 5,000+ posts]

um yeah dude, where is the crossover that you are suppossed to be using???? they look like little coffins... I think I know why you chit is *******... first off, your tapping in. Second, you just might have ths polaity reversed . If you dont have the crossovers, you need to fine some, otherwise you will burn out those tweets. Them are some good speakers yo. I love mine!. do it right and it will be tight....

who the hell hooked those up? it looks completely wrong.....

 

[ARK_SWAMP_RIDER 10+ year member]

I've hooked the wires in on both sides of the speakers, with no difference in performance. As for who put in the SS 6x9's, I don't know but its a very bad job. I'm new at this, but it just seems poorly put together IMO. Polarity isn't reversed, we've double and triple checked that. Where would the crossover be? I'll admit I'm new and learning. I wasn't aware of the aftermarket stuff in there when we started, but I knew I did my install fine on my vehicle so didn't think this would be an issue. The important thing now is getting this up and running. Thanks for any help!

 

[Steelers6Time 10+ year member]

i would follow the wires from the speakers back. if you can tap the wires before that x-over you should be good. come to think of it, it looks like the second pic the crossover was possibly glued to the bottom of the motor on the 6x9? also i see some electrical tape after the little white plug and before the speaker connections....try tapping the wire before that if there is no crossover. if hes not running the crossover then I have no clue how he has that shit wired.

 

[keep_hope_alive Premium Member]

notice how the wires from the speaker terminate in a 4-pin molex plug? does Soundstream do that?

you must trace that wiring, inspect the entire run. You need to determine where they terminate, hopefully at a passive crossover (looks like a circuit board with capacitors and inductors in a plastic case).

but to the original issue:

you are using high level inputs on the Amp. verify in the owner's manual if there is any switch necessary to choose high level inputs. or provide the model number and we can look it up for you (you should read it anyway).

how did you determine your amplifier gain/input sensitivity setting? what is the crossover set at? Crossover should be on LPF and ~80Hz.

 

[ARK_SWAMP_RIDER 10+ year member]

The amp is a Kenwood KAC-5204. I read the manual, no switches or anything to use. It came as part of a package, number on that is P-w1000. I think the x-over is right by the speakers. I saw this, and wasn't sure of its function. For the gains, I'm shooting for 24.5 volts (square root of [150 watts x 4 ohm load]). I get nothing. There isn't an adjustment for LPF, only a switch turning it on/off (on is set at 80 Hz). I do remember seeing a pair of wires coming in, but they are different colors and I'm unsure how to tell which is + and which is -. I read about the battery trick for testing at the speaker, but not sure on wires that are hooked in. Here is another pic, you can see the board I'm talking about, which I think is the x-over. So, I should be able to tap into the other side of this (side going away from speakers) and it'll work if I'm understanding you guys right. The taps you see in the pic were there when we started. Those aren't the taps we are using, none of my wiring is visible in the pics (had it unhooked at the time).

 

[Steelers6Time 10+ year member]

OK... So here is your problem. What you need to do is remove all the wires you installed and start from scratch. The problem from what I can figure with the "spaghetti" mess of wires is that you have, you should tap into the the factory speaker wire before the crossover. All you should have is 2 factory speaker wires (with your taps attached) running to the crossover, one set of wires going to the mids and one set going to the tweeters. Simple. If you are still having problems with this set-up... take it to a reputable installer. If your buddy is driving a Lexus... (as indicated) he CAN afford $40 to have the set-up done properly. Hope this helps!

 

[ARK_SWAMP_RIDER 10+ year member]

I just got finished working on it, and I feel like I made some progress. I'm really not sure what to expect though. I found the crossovers, they were right by the speakers. I tapped into the wires before you get to them. These weren't the factory wires, as the colors weren't right. I was unable to get to the factory wiring, wasn't ready to remove the seats and rear deck. The wiring wasn't consistent, colors were crossed everywhere. It was a huge pain. We finally got all the wires hooked up and tested it out. Sound was better than before, still not right though. I tried flipping the wires (ones I was tapped into), and this doubled the sound (still wasn't right though). I was testing with the multimeter, and with it set at AC 250 (just a cheap analog meter), I barely get a reading (with gain all the way up, it was at like 5 volts). We then switched the + and - sub output, and the sound improved yet again. I have no idea why the sub output had to be switched, it goes against all logic. I guess we've got something backwards somewhere, but couldn't find it. So, the end result is a system that is actually working. However, I'm not convinced that it's putting out to its full potential. I have a JL J2 250.2 pushing a single JL 8w1v2 (150 watts RMS at 4 ohm load). His setup is a Kenwood package consisting of two 10" subs that are 350 watts RMS, and a KAC-5204 amp that puts out 150 watts RMS bridged (speakers are 8 ohm SVC, so 4 ohm load when bridged). My single 8 outperforms his two 10's. I realize the two 10's are way underpowered, but I expected more. It's in the trunk facing forward, and it's able to be heard, but it isn't gonna shake the car. We've got the bass on the H/U turned up, LPF on, and gains maxed out (well, I backed them off just a little so they were fully maxed). Any thoughts/comments? The Kenwood amp may be underrated and not even pushing the 150 watts, so that is probably an issue. I just want to make sure the wiring isn't the issue. He got the subs at a good price, so he's considering a larger amp that'll push them better (in the future, he's happy for now). Thanks for the help guys, I really appreciate it!

 

[keep_hope_alive Premium Member]

try getting a LOC and using the RCA inputs on the amp.

 

[ARK_SWAMP_RIDER 10+ year member]

try getting a LOC and using the RCA inputs on the amp.

Using the same wires to tap into?

 

[keep_hope_alive Premium Member]

sure, but ideally you'd tap behind the head unit so you know what wires you're using.