ryuandwings

I need your help guys. I have trying to deal with this for a few weeks
and I tried everything I can think of.
Here is what I got going. I have a headunit less setup.

Computer ->USB SoundBlaster MP3+ ->AMP -> speakers

Above is the basic setup. I have tried

computer-> USB SoundBlaster MP3+ ->home stereo

setup and worked, so I know computer and soundcard work.
The problem seems to be somewhere at the AMP and speakers.
AMP is hooked up to battery and ACC. I checked that so many times
so I think AMP is connected fine.
sound card is connected to AMP by RCA cables into AMP input.
Also, I bought another AMP to test and I got same result. Nothing.

What am I doing wrong? I have been testing with one speaker, do I
need to have all speakers connected get any sound?

Anything will be great at this moment, I will try any thing.

MP3Car.com

 

MrPerfectionest

A) I assume you have the amplifier grounded also.
B) Do you know if the amp is turning on? Is there any kind of an LED that would indicate it is on?
C) Are the output levels so drastically low on your sound card and the gain so low on your amp that you just can't hear any sound (essentially like having the volume all the way off).

D) What is the amp model number so we can see if we can discover any other problems.
E) Such as, if it is a 4 channel amp, it might be possible to set it in a way that it only needs input from 2 of the channels and you have the cables connected to the wrong inputs.

ryuandwings

Thanks for quik reply ,
A) It is grounded
B) AMP is on. I can see LED's turn on when I try both AMP
C) I have to check that. But should be set somewhere in middle.
D) First AMP is Pioneer GM-X374.
Second test AMP is Sony AMP (I can't remember the model number)

Thank for your help.

falconey

Can you take a pic of your connections? That would help cancel out some of the troubleshooting if those connections are set up properly.

Also this may be a stupid question but I don't know your car audio knowledge. Did you run the speaker wires from the car speakers to the amp?

If the amp is powering up and no sound has ever been produced from it then I wouldn't think it's blown so it would have to be the speaker connections. There could be a possibility that the speaker wires are connected properly but either the ground, power, and acc wires are not and the amp is going into safe/protect mode.

MrPerfectionest

Have you tried taking a bare speaker so that you know for certain you have a connection from your amp to the speaker?

If two different amps aren't doing anything, and they are both powered on, then the last link is certainly the speaker.

What kind of car is it? Is there a factory amplification system you are dealing with that could be causing the trouble?

Do you have your crossover accidentally turned on which would exacerbate the gain problem I mentioned earlier. The best debugging step is definitely to take the speaker to the amp and wire it directly so that you can see for yourself if there is a connection.

ryuandwings

Thanks guy for your input.
I am at work now, so I will try to work on this tonight and let you know
what I find.

ryuandwings

My car audio knowledge is very minimal. I only know the basics.

When I connect my headunit to the car stereo (basically the factory setup)
everything works. So every componets are in working condition.

Do I need to do anything special on ACC? I just got it from the fuse box.
What is the safe/protect mode? How do I check that?

falconey

Ok based on this info I'm thinking you don't have your setup properly installed. Not a flame or anything I just think you've missed a step somewhere. First off you may want to tell what type of car this is, because someone may know if there's a factory amp which could be the problem. Aslo based on the comment about the head unit and car stereo it seems your saying when you connect the head unit back up you get sound from the speakers. I say it seems like that's what you're saying because you say 'head unit to car stereo'....the head unit is apart of the car stereo so I just have to guess what you mean there. If you are saying that without any modification you can hook the head unit back up to its original harness and you get sound from the speakers then we already know your problem. You haven't rerouted the speaker wires to the amp. Or have you? If you have I'll keep trying to help you, if you haven't then that's your problem.

MP3Car.com

 

falconey

Sorry forgot to mention I really don't think it's an amp issue or a power issue so I wouldn't worry about that too much unless it ends up not being a speaker issue. ACC only needs to be connected to a source that will only produce power when the key is turned to acc...that's the special thing about it.

ryuandwings

Sorry for the confusing statements.

What I was saying about headunit is that, if I do not use the AMP and plug my headunit back into the harness I get sound comes from speakers. This is the original setup just as it came from factory.

When I was test the AMP, I pulled out one of the speaker from the door and connected it to the AMP. I used laptop->sound card->AMP->speaker setup to test.
Does that make sense?

My car is 1997 Subaru Outback Sport, and I don't think there is a factory AMP. But I really don't know.

falconey

That makes perfect sense and that's how you should have tested. As far as the factory amp goes it wouldn't matter if you took the speaker completely out and ran it directly to the aftermarket amp. So as long as your confident that you connected the speaker wire correctly, had your rca's in correctly, and the key to the car was at least at ACC then you're problem has to either lie within the amp or the wiring. Now you stated that you tried another amp so that gives me the impression that it's the way the wiring is set up. Now I'm in back-track mode because you've stated the amps are powering up. At this point I'm stumped. The only thing left to suggest is that the amp or in this case amps are blown. Highly unlikely that you'd have two seperate amps that are blown and especially if either or both are new. If there's anything you've left out on purpose or unknowingly let me know and maybe I can come up with something else.

ryuandwings

I am thinking it is wiring somewhere, too. At least that is what I am hoping .
I am going to check the wiring again.

MikeHunt79

ok, I havent read the whole thread since i'm lazy, but try wiring up a portable CD player or something like that just to see if u can get any sound out your amp at all, then go from there.

__________________
My Setup

shillier

Hummm... had the same problem when I tested my first setup which I also tested with a laptop.

Took me a couple hours to figure out. First thing was that I had the wiring hooked up to the microphone jack. Then the 3.5 stereo wire was not plugged in all the way in the headphone jack. Then I had some tweaking to do in the volume controls and uncheck all the mute settings. Can't remember exactly what I did that fixed it but the problem ended up being related to the settings on the laptop I was using which I think was a Compaq Armada M700. I was testing DVDs at the time.

In my opinion, it's your wiring of the laptop or some specific setting in the software. It sounds to me that the amp is wired properly and the speakers. I would focus on the laptop and the wiring. Try a different source as suggested above.

Good luck!

ryuandwings

Thanks guys for the suggestions.

The funny thing is that same laptop->usb sound card setup works when I hook up to home reciever. So I am thinking it is somewhere in the car.

Also, I have tried with portable CD player and MD player with no sound. Which also lead me to think it is not the source.

Well I am going to rewire everything this weekend. I hope I will find something.

MP3Car.com