blown amp? - The Unofficial BMW M5 Messageboard (m5board.com)

gsfent · 20th January 2008, 20:35

Recently, I have been getting a strang "pop" in my right front door speaker, most often when the car is started. Also intermittantly during drives. With radio off, still occurs on startup. Sound is ok though. So, no emergency, but on the list to fix.

Today, no pop on startup. A few minutes later, anothe pop and then a noticable change in sound. All the "depth" is gone, everything sounds kind of tinny, like listening to AM on a mono radio.

Radio still shows stereo and condition is the same on CD. Now, I do have a bunch of Nakimichi amps driving my stereo, and still have the DSP. 'also, all the speakers were replaced sometime back with JL's.

Anyone hazard a guess? Could be a fuse, but the annoying "pop" were probably a precurser to something shorting out.

Any suggestions? Will probably have to wait until next weekend before I can get it looked at. Just have to listen to the melody of the s62 mit headers.....

Regards,
Jerry

jetblack01m5 · 20th January 2008, 21:42

Have you checked the connections at the speakers? I was getting a pop like that on my front passenger speaker and the connection had come loose.

gsfent · 20th January 2008, 22:38

Quote:

Originally Posted by jetblack01m5

Have you checked the connections at the speakers? I was getting a pop like that on my front passenger speaker and the connection had come loose.

No, but the speaker seemed to work.

But now ALL the sound is lousy, not just the speaker, so I tend to discount the current problem as just the speaker (although it may be on its way out also).

I think I have another problem and the only thing I can think of effecting radio and CD would be an amp. I don't know if it is the original or the Nakamichi's. Not even sure where the fuses are that power everything up, as I had some pros do the wiring and install.
Regards,
Jerry

jetblack01m5 · 20th January 2008, 23:52

I really don't think a fuse would have blown since if a fuse blows you loose the connection.

If all the sound is lousy.. it could be the bmw radio that controls the radio, cd, etc. However, when it comes to trouble shooting audio I really find it hard to pin the blame on an amp or component without first checking all of the wiring connections and fuses. Is it possible for you to disconnect your Nakamichis and then test them one at a time whlie playing music through the stereo? If all the Nakamichis come out with the same bad sound you can assume that it is something that they all connect to and not the Nakamichis.

Maybe some of the audio wizards will chime in soon... good luck on hunting down the problem.

gsfent · 21st January 2008, 00:29

Quote:

Originally Posted by jetblack01m5

I really don't think a fuse would have blown since if a fuse blows you loose the connection.

If all the sound is lousy.. it could be the bmw radio that controls the radio, cd, etc. However, when it comes to trouble shooting audio I really find it hard to pin the blame on an amp or component without first checking all of the wiring connections and fuses. Is it possible for you to disconnect your Nakamichis and then test them one at a time whlie playing music through the stereo? If all the Nakamichis come out with the same bad sound you can assume that it is something that they all connect to and not the Nakamichis.

Maybe some of the audio wizards will chime in soon... good luck on hunting down the problem.

Thanks for the suggestions. Not sure how all the Nakamichi's are hooked, but I can access through the trunk and perhaps figure out how to disconnect one at a time. Of course, I don't want to screw anything else up, so I will be proceeding cautiously until I can get someone knowledgable to look at it.
I wonder if it could be just the sub? I wouldn't think all the fullness would be attributed to that, just the extra bass.
Regards,
Jerry

jetblack01m5 · 21st January 2008, 03:09

Quote:

Originally Posted by gsfent

Thanks for the suggestions. Not sure how all the Nakamichi's are hooked, but I can access through the trunk and perhaps figure out how to disconnect one at a time. Of course, I don't want to screw anything else up, so I will be proceeding cautiously until I can get someone knowledgable to look at it.
I wonder if it could be just the sub? I wouldn't think all the fullness would be attributed to that, just the extra bass.
Regards,
Jerry

I don't think it could be a sub. Normally they are driven by an amp or channels on an amp that has a low pass filter rendering the amp or channels for the subwoofer to bass only signals. Fullness is normally the midrange speakers.. so maybe the amp or the crossovers driving the tweeters / midranges is having issues?

DouglasABaker · 21st January 2008, 03:50

Hi Jerry,

I'm presuming based on your above comments that you have a Cleansweep or equivalent installed?

You have an '01, but do you have the digital coax cable connecting your CD Changer to your amp, or do you have the 3 pin connector that connects it to your radio?

If you have the cable connecting it to your amp, then I will state with near certainty that your issue is the amp.

If you have a cable connecting your CD to your radio, then I'm only willing to go 95% that your amp is bad, but it is possible the radio is bad. The only way I know to determine which is to connect the radio outputs directly to a speaker and listen to it. Normally you can do this with the RCA's, but in your case you'll need to disconnect the DSP amp input harness and stick a couple of wires into it to check. If it sounds ok, then your amp is bad. If it doesn't, then your radio is bad.

d-

gsfent · 21st January 2008, 04:30

Quote:

Originally Posted by DouglasABaker

Hi Jerry,

I'm presuming based on your above comments that you have a Cleansweep or equivalent installed?

You have an '01, but do you have the digital coax cable connecting your CD Changer to your amp, or do you have the 3 pin connector that connects it to your radio?

If you have the cable connecting it to your amp, then I will state with near certainty that your issue is the amp.

If you have a cable connecting your CD to your radio, then I'm only willing to go 95% that your amp is bad, but it is possible the radio is bad. The only way I know to determine which is to connect the radio outputs directly to a speaker and listen to it. Normally you can do this with the RCA's, but in your case you'll need to disconnect the DSP amp input harness and stick a couple of wires into it to check. If it sounds ok, then your amp is bad. If it doesn't, then your radio is bad.

d-

OK, what foreign language was that?

I don't know what cable is connecting the amp, (late build May '01), but I also have a set of three Nakamichi amps/crossovers installed to run everything. The wiring was done by our local high end car stereo shop.

To make matters even stranger, on the way home tonight, I start the car with the radio now off. I get a samll "pop", go to the trunk where the extra amps are, and see the Nakamichi's are powered up even though the radio is off (so I am guessing amps, not radio problem, although I can't tell whether nakamichi amp or dsp amp issue).

Turn on radio and WTF? Everything sounds normal!
Drive home, switch from radio to CD and back, all is good.

I will still get this checked out at the stereo shop that did the install, but at least temporarily, I have tunes!
Regards,
Jerry

DouglasABaker · 21st January 2008, 04:57

Quote:

Originally Posted by gsfent

OK, what foreign language was that?

I don't know what cable is connecting the amp, (late build May '01), but I also have a set of three Nakamichi amps/crossovers installed to run everything. The wiring was done by our local high end car stereo shop.

Geek

You are on the wrong side of your amplifier - I know you have amplifiers after your DSP amp, but we need to determine what is happening before your amp...

Go to your CD changer. Loosen the 2 screws on the forward facing side of the bracket. This will allow you to lift the CD Changer up and out to look at the bottom. If you see 1 rectangular and 1 round plug, then your factory amplifier is bad. If you see 2 rectangular plugs then you need to do the test I indicated earlier, or take the car to someone who speaks geek

Quote:

Originally Posted by gsfent

To make matters even stranger, on the way home tonight, I start the car with the radio now off. I get a samll "pop", go to the trunk where the extra amps are, and see the Nakamichi's are powered up even though the radio is off (so I am guessing amps, not radio problem, although I can't tell whether nakamichi amp or dsp amp issue).

As they should be - if the ignition is on, so are the amps. No amps, no directions from your navigation system

Quote:

Originally Posted by gsfent

Turn on radio and WTF? Everything sounds normal!
Drive home, switch from radio to CD and back, all is good.

I will still get this checked out at the stereo shop that did the install, but at least temporarily, I have tunes!
Regards,
Jerry

Another successful problem resolution - let me know if you need any more help

j/k - it sounds to me like you have an intermittent short in one of your components. My money is still on the stock amp...

btw - it is highly unlikely all your Naks failed at once unless there was a serious power short somehow. I wouldn't worry about them...

d-

gsfent · 22nd January 2008, 16:08

Quote:

Originally Posted by DouglasABaker

Geek

You are on the wrong side of your amplifier - I know you have amplifiers after your DSP amp, but we need to determine what is happening before your amp...

Go to your CD changer. Loosen the 2 screws on the forward facing side of the bracket. This will allow you to lift the CD Changer up and out to look at the bottom. If you see 1 rectangular and 1 round plug, then your factory amplifier is bad. If you see 2 rectangular plugs then you need to do the test I indicated earlier, or take the car to someone who speaks geek

As they should be - if the ignition is on, so are the amps. No amps, no directions from your navigation system

Another successful problem resolution - let me know if you need any more help

j/k - it sounds to me like you have an intermittent short in one of your components. My money is still on the stock amp...

btw - it is highly unlikely all your Naks failed at once unless there was a serious power short somehow. I wouldn't worry about them...

d-

The problem was kind enough to reoccur on the drive home last night. So I left everything on and went to the trunk where the amps are mounted: the left amp is showing a red light instead of green light! So, no power (for whatever reason). That of course explains the lose of sound.

It appears my right and left amps are plugged into the center amp, so whatever the left amp controls (midrange??) is intermittantly going off/shorting out. At least I know where to focus the repair. Could be as easy as a bad wire or as bad as an amp going south...
Regards,
Jerry