Possible Bad Amp?

**VetteC5RFrEak** · 03-16-2008, 05:15 PM

Back in August/September (2007) I installed a Hifonics 4 channel amp, 2 Infinity 3-way 6x9's (rear) and 2 6" + tweeter components (fronts) in my '95 Mzda 626.

About a month or so ago, the right front speaker would start popping every now and again, then eventually got unbearable. It sounds as if you hook one speaker lead to the positive side of a AA battery, and the other speaker lead to the negative side. Or, like a loose connection. I figured it was a loose wire, so I just disconnected that channel at the amp until I could find time to locate where the loose wire was.

Well, just within the past few days, the left rear is doing the same thing. So today I went and swapped the outputs for the rear channels to see if it was loose wiring, bad speaker, or something to do w/the amp. The popping sound went to the right rear when I swapped channels, so it isn't in the wiring from the amp to the speaker, nor the speakers.

I was thinking, okay, it is either the wiring from the H/U to the amp, or the amp itself. I disconnected the RCA's at the amp so there is no input going into it, there is still popping coming from the one speaker.

What is going on here? I have the amp grounded within a foot to the body, it was the shortest ground I could run. I drilled a hole through the inner fender support and ran a bolt and washer through, after scraping off any paint in the way.

Ideas would be greatly appreciated. I hope it isn't the amp, but I don't know what else it could be. Thanks.

**brucedog** · 03-16-2008, 11:03 PM

Hopefully you did not operate the amp with no speaker connected to any particular channel. You must always have a "load" (speaker connected or the amp may blow. Most modern amps have sensing protection to cover you, but don't take chances.

To test the amp, always keep things simple:
>with the power off
>disconnect all speakers from the amp that have the problem - only keep the known good-sounding ones connected
>use your mp3 player as amp input music signal
>get some known good speakers out of the house or wherever...these will be connected to the suspect channels
>fire up the amp at low volume level, increase vol gradually and listen for problems

If the same bad noise is still there, your amp has blown something.

**VetteC5RFrEak** · 03-17-2008, 12:11 AM

Originally Posted by brucedog

Hopefully you did not operate the amp with no speaker connected to any particular channel. You must always have a "load" (speaker connected or the amp may blow. Most modern amps have sensing protection to cover you, but don't take chances.

To test the amp, always keep things simple:
>with the power off
>disconnect all speakers from the amp that have the problem - only keep the known good-sounding ones connected
>use your mp3 player as amp input music signal
>get some known good speakers out of the house or wherever...these will be connected to the suspect channels
>fire up the amp at low volume level, increase vol gradually and listen for problems

If the same bad noise is still there, your amp has blown something.

Essentially, couldn't I just swap channels? Say, I have Channel 1 to the Front Right (FR) and Channel 2 to the Front Left (FL), Channel 3 to Rear Right (RR) and Channel 4 Rear Left (RL). Then swap FR to FL and FL to FR; RR to RL and RL to RR. If so, that is what I did with the RR and RL. Instead of RR being Channel 3 and RL being Channel 4, I made it so RR was Channel 4 and RL was Channel 3. The sound went with the Channel and not the speaker.

And yes, I did run the amp with no load on one of the channels for a while because like I said I was getting that noise through the RF speaker and figured it was a loose wire and didn't have the time to go and pull the door panel off to try and locate it. But, before that channel went bad, all channels had a load on them. The AMP has never went into Protection mode, nor have I ever blown any fuses, and there are no shorts in any of the wires.

Does Hifonics have a reputation for their amps going out? I have a Crunch amp (a derivative of Maxxosonics who makes Hifonics) that I have used in my Camaro for about 4 years now and never any issues with it; and all I paid for it was $40 from Fry's Electronics.

**durwood** · 03-17-2008, 12:00 PM

Originally Posted by brucedog

Hopefully you did not operate the amp with no speaker connected to any particular channel. You must always have a "load" (speaker connected or the amp may blow. Most modern amps have sensing protection to cover you, but don't take chances.

Are you kidding me? Where did you pick up this idea up from? This is completely untrue.

To the OP,

If the popping sound followed your wiring, I.E. you swapped the speakers leads that now the popping is coming from the other side, it could be a couple of things:

1) Bad RCA cable or porr connection of the RCA signal/plugs. Check all connections and try other RCA cables to make sure.
2) Loose power connection. Grounds, battery, fuse, etc etc. Check everything to make sure it's tight. Test with the voltage with DMM at the amp.
3) Could be a bad amp, but more likely I'd look through your install very throughly.

**VetteC5RFrEak** · 03-17-2008, 03:49 PM

Originally Posted by durwood

Are you kidding me? Where did you pick up this idea up from? This is completely untrue.

To the OP,

If the popping sound followed your wiring, I.E. you swapped the speakers leads that now the popping is coming from the other side, it could be a couple of things:

1) Bad RCA cable or porr connection of the RCA signal/plugs. Check all connections and try other RCA cables to make sure.
2) Loose power connection. Grounds, battery, fuse, etc etc. Check everything to make sure it's tight. Test with the voltage with DMM at the amp.
3) Could be a bad amp, but more likely I'd look through your install very throughly.

I will definitely re-check the installation. However, with the RCA cables unplugged, the amp still makes the noise. So wouldn't that eliminate the fact that it could be bad RCA's? That it is something internally, or possibly the power/ground to the amp?

Sorry if I sound like a 'tard here, but I just want to be clear on what you are saying. By DMM, you mean Digital Multi-meter? And check the voltage at the power and ground connection of the amp to see if they are reading close to the same voltage as the battery (it won't be exact due to the wires and resistance, but should be close), right? Thanks.

**ArcaneDreams** · 03-22-2008, 07:20 PM

Ok, so you have 4 channels each connected to 1 single speaker correct?

It sounds like your amp is going bad if only certain channels are outputting a popping noise.

It cannot be bad wiring if your speaker that was popping sounds fine on a different channel. (duh)

By chance were you sure to match up your ohms from your speakers to your amp? If your speakers have a lower ohm rating than your amp can handle it can easily cause your amp to go bad.

Either that, or it was just the amp's time to die.

That would be my best guess as to why.

**VetteC5RFrEak** · 03-22-2008, 11:56 PM

The amp is a Hifonics TXi4406: 110rms x 4 @ 2 ohms.
The Speakers are Infinity 6020cs: 2-90 rms @ 2 ohms and Infinity 693.7i: 2-110rms @ 2 ohms.

I am hoping the connections inside the amp at the RCA to circuit board are loose and can be soldered back on tightly. I bought this amp from Millionbuy on Ebay on August 22nd, 2007 and it was supposed to be brand new. It was in the original packaging and had all the original equipment with it.