Engine noise?

[Simon.h]

Hi all,
I had this engine noise/alternator whine for 2 years and it starting to drive me mad! It can be heard from about 1800rpm upwards with the radio/cd etc.. on low/normal volume but if the volume is loud I can't (but can between tracks).
I have Seans D.Din head unit and 2 amps in the boot, 1 powers 2 pairs of component speakers in the doors and the other a bass box in the boot so no speakers are powered from the head unit.
I have 2 suppressers on the alternator (see picture) which have helped a bit and the alternator has just been changed (which made no different).

Any ideas??

[coolcat]

Originally Posted by Simon.h

Hi all,
I had this engine noise/alternator whine for 2 years and it starting to drive me mad! It can be heard from about 1800rpm upwards with the radio/cd etc.. on low/normal volume but if the volume is loud I can't (but can between tracks).
I have Seans D.Din head unit and 2 amps in the boot, 1 powers 2 pairs of component speakers in the doors and the other a bass box in the boot so no speakers are powered from the head unit.
I have 2 suppressers on the alternator (see picture) which have helped a bit and the alternator has just been changed (which made no different).

Any ideas??

Hi Simon ,

Have you tried moving your earth points around on your amps?
Also, how good is the screening on your phono leads from the head unit to the amps and do they pass alongside the power cables? If its a poor quality phono lead change it and try and keep its path clear of the high power positive cable run.
The other thing you could try is a ground loop isolator on the phono leads
Good luck and let us know how you get on.

[Simon.h]

Originally Posted by coolcat

Hi Simon ,

Have you tried moving your earth points around on your amps?
Also, how good is the screening on your phono leads from the head unit to the amps and do they pass alongside the power cables? If its a poor quality phono lead change it and try and keep its path clear of the high power positive cable run.
The other thing you could try is a ground loop isolator on the phono leads
Good luck and let us know how you get on.

Hi,
No I have not tried moving moving the earths but I know they are nice and clean. I will try this.
How do I know if the screening is ok or not?
Phono leads run down n/s and power cables o/s.
Ground loop isolator? What's this?
Sorry I'm I be thick on this sort of thing.

Thanks.

[coolcat]

Originally Posted by Simon.h

Hi,
No I have not tried moving moving the earths but I know they are nice and clean. I will try this.
How do I know if the screening is ok or not?
Phono leads run down n/s and power cables o/s.
Ground loop isolator? What's this?
Sorry I'm I be thick on this sort of thing.

Thanks.

Thickness of the phono cables is a reasonable marker for how well screened the cable is.
A ground loop isolator stops earth potentials and plugs inbetween your phono leads.
We sell them in our forum shop but they are readily available from most car audio dealers or off the Internet

They come in various shapes and sizes but commonly look something like this..