Whistling noise

[sayers]

Help. My car radio whistles badly with the pitch of it increasing with the engine revs. What the heck do I do to cure this. It's worse now a crossover has been fitted

[JeffTT]

Help. My car radio whistles badly with the pitch of it increasing with the engine revs. What the heck do I do to cure this. It's worse now a crossover has been fitted

 

An alternator not fitted with a suppressor will produce a whining sound, rising in pitch as the engine speed increases, also earth loop inpedance issue`s can cause the the same where the earth point used is not as good as the battery earth. Also less expensive audio components can be badly shielded so badly sometimes they produce their own interference from bad designed internal power units.

 

Here is a good read on the subject: http://www.mp3car.com/car-audio-faq/79248-induced-noise-ground-loop-trouble-shooting-guide.html

 

 

Jeff

[sayers]

Thankyou how do I supress the alternator please

[JeffTT]

You need to fit one of these :

 

 

to the back of the alternator, between the main power feed and the earth of the alternator, bit of a pain as you will need to remove it to get to it, however be easier when your doing the manual conversion.

 

As an alternative you could try moving the earth point to any amplifiers or the crossover if it is a powered active one, also check the earth to the back of the head unit is connected, this can be missed and it then relies on the earth through the aerial which can be problematic, finally if your using phono line out fit a line suppressor after the head unit before it goes into any amps or crossovers.

 

 

 

Jeff

[veilside01702]

A lot of the time it is just a simple bad earth to the head unit / crossover...... is the head unit earth using the original power wires?

You can always add a second earth to the head unit and crossover, taking it directly from a good earthing point!

I am guessing you have amplifiers fitted if you are running a crossover?

Any issues at the front end will be amplified and fed through the speakers.....

[AndrewG]

Help. My car radio whistles badly with the pitch of it increasing with the engine revs. What the heck do I do to cure this. It's worse now a crossover has been fitted

 

What is the setup of your system (including location of components)?

Edited February 6, 2016 by AndrewG