Speaker distortion, very very confused

[rufman]

hello folks
got an e55, 1999. was getting lots of speaker distortion with the orginal factory fitted stereo and speakers at anything above a third of the volume so changed the whole lot. Put in a new stereo and new front speakers as that seemed to be the most obvious thing to do.

however, the problem was still there so took off the door panels again and tried with another stereo (top spec alpine) and other speakers (good new jbl's) but cant rid of the bleeding distortion.

has any one got any ideas before i end up spending lots on wiring issues.

any advice would be great as I'm baffled as to where the problem could be.

Thanks

 

[fuzzer]

what kind of distortion?

Most likely be something allong the lines of a bad earth?

Do you have the upgraded bose system? They have a seperate amp other than the head unit

 

[grober]

Are you using the correct impedance of speakers normally 4ohm or 8ohm and are they wired correctly separately or in series or parallel because this will effect the impedance "seen" by the output stages of the head or power amplifier? Too low an impedance will cause distortion as you describe. Are the speakers rated to handle the power output by the headunit/amp. If the head unit is outputing to power amp first is the "signal out "level too great for the amp input??

It all sounds like a component mismatch to me. Check all your ratings on all your sound system components and then check the wiring setup.
Thats my tuppence worth!

 

[Howard]

Remember that Alpine stereos have a 4v pre-out (amp feed) ...

This is higher than any other manufacturer , so its possible that the amp is recieving a line level input that is too large for it to handle .... If you are going Alpine stereo , its best to have Alpine amps (that are designed for the 4v input)

Have you tried adjusting the gain on the amp ?

I agree with Graeme, component mismatch is the likely culprit ...

Good luck !!

 

[rufman]

cheers for the replies.

the distortion is a severe crackle. I thought it had a bose set up as the rear shelf speakers have the bose covers but because of this poblem I took them off to see what was underneath..certainly not bose! same for the front door speakers. The fronts were 2 ohm and i would suspect the rears are as well. I've changed the stereo to a blaupunkt santa cruz as it looks well in the dash and changed the speakers to new fly by vibe 3 way (sound pretty good on a non distorting system!) so i suspect the stereo and front speakers are now compatible with each other.

Would changing the rears bringing them in line with the new fronts do it? Don't want to spend more if the problem lies elsewhere! ( i have a c4 which desperately needs rear tyres but all my money is being ploughed in to the e55!).

by the way, no amp either or subs in the back.

Thanks again.

 

[bolide]

Logically, if you've changed the HU and the speakers, and the distortion's still there, they're not the problem

It's unlikely, but I'd check the connections & fuses on the power feed to the HU. If you have a badly corroded fuse it can cause distortion at high volumes

To properly track down the problem you'll need to pull out the HU and speakers, run in a temporary live feed to the head unit & run some temporary speaker cable to test all the component parts before fitting them

If all the bits test OK then the problem's in the cabling or power feed, or there's something you don't know about in the cabling (like a Bose amplifier), or the crackling is a mechanical thing with one or more of the speakers or mounts

If you go back to first principles and test everything one piece at a time you will find the problem


Nick Froome
www.w124.co.uk

 

[rufman]

not changed the rears yet but will now do them so that should cover all the speakers and hu..

other than that it looks like its going to be a nightmare sorting this out as it looks like it has more wiring han ive ever tackled.

cheers