Speaker Hiss After Installing An Amp + 4 New Speakers

[Concert D Major]

This is on a 2013 Honda Accord LX 4-Door. I had a local stereo place install an amp and 4 speakers to replace the stock ones. Now I get a pretty good hiss / white-noise sound if the head unit volume is all the way down or if the radio is turned off altogether.

The amp was installed with the gain all the way up, so I turned it half way down for the front and back speakers. This lowers he hissing sound but it's still there and now the amp is not as loud with the gain down.

This is on a Rockford Fosgate R600-4D amp, Rockford Fosgate Power T1652-S speakers, and Image Dynamics CTX-65 speakers in the rear. The hissing sound is there whether the engine is running or not.

Is there a way to troubleshoot this, or should I go back to the installer?

Thanks.

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[trumpet 5,000+ posts]

The amp was installed with the gain all the way up

It's **** like this that gives shops a bad reputation. Your amplifier is probably getting a signal from a line out converter, and unless they turned it all the way down they had no business turning the gains all the way up. What you described should never happen if they had any integrity to fix the problem before giving the car back to you.

If you know, tell us what they used to get RCA low level signal into the amplifier. It seems you must have the factory radio yet, so there has to be a converter somewhere. I don't recommend you touch the converter or any other settings until you take the car back and have them fix it. There shouldn't be any noise if it's properly set up.

 

[Concert D Major]

I'm not sure about the RCA low level signal (not sure what that is?), but this is the stock radio. It's not a typical DIN head unit. It's integrated into the screen on the dashboard.

 

[Concert D Major]

I called the shop and they said some newer cars have this problem because of automatic noise cancelling microphones inside the car (the Honda has this). They said it's been an increasing problem they've been seeing more of.

I tried disconnecting the RCA front speaker inputs to see what would happen. That reduced the hiss on the front speakers by about 50%, but there is still a hiss (with the engine not running and the radio volume all the way down).

I guess I don't understand how if you unplug the front input RCA plugs how there would be any sound at all from the front speakers, much less any hissing noise.

 

[NIHL8ION]

I called the shop and they said some newer cars have this problem because of automatic noise cancelling microphones inside the car (the Honda has this). They said it's been an increasing problem they've been seeing more of.
I tried disconnecting the RCA front speaker inputs to see what would happen. That reduced the hiss on the front speakers by about 50%, but there is still a hiss (with the engine not running and the radio volume all the way down).

I guess I don't understand how if you unplug the front input RCA plugs how there would be any sound at all from the front speakers, much less any hissing noise.

That's because there shouldn't be lol - If your amp is making a hissing noise with no input connected than something is set-up improperly (faulty ground maybe?) or that amp is just garbage...

 

[Concert D Major]

If it's a bad amplifier, then should disconnecting the front speaker RCA input plugs on the amp make no difference? When I unplugged 'em, there was still a hiss but it was quieter.

I wonder if I might have the shop swap out the amp with another one and see what happens then, if they have a spare/used one lying around. Then we could put the Rockford on a set of their speakers in the shop and see if the amp is bad.

 

[NIHL8ION]

If it's a bad amplifier, then should disconnecting the front speaker RCA input plugs on the amp make no difference? When I unplugged 'em, there was still a hiss but it was quieter.
I wonder if I might have the shop swap out the amp with another one and see what happens then, if they have a spare/used one lying around. Then we could put the Rockford on a set of their speakers in the shop and see if the amp is bad.

If you paid them to do your install, then you most certainly should go back and MAKE them make this right.... That's total B/S

 

[Concert D Major]

I called the installer back and they said it's prolly a bad amp and they tried to talk me out of coming back. I told them I'd like to have them try swapping out the amp to see what happens. So we setup an appointment for Saturday, but they said they're gonna charge for the labor. This is proving to be a disappointment.