Engine Noise Through XM Radio

[AVIA8R]

I have a 2002 Carrera 4S. I just added the Terk "XM Commander" XM radio receiver to my factory CR-220. I'm now getting a LOT of radio noise when I use the XM radio. It's so loud, that it's not even worth using it when the engine is running. It sounds great when the car is off. I used the Becker accessory kit to use the RCA inputs. I first used the Cell Phone connector for power and ground. I then moved the ground to a nearby structure screw and the power lead from the Becker radio. This did not fix it. I've installed at least a dozen or so radios, but have never had this problem. Does anyone have any suggestions or has anyone else ran into this? Help. Please.

[Thanatos69]

I might recommend trying an inline noise suppression filter like the ones listed on the sites below. Either the inline power or audio filter should help out.

http://www.allaudioexpo.com/nav/listing.asp?catid=79

http://www.audiooutfitter.com/store/cats/6...isefilters.html

[bavarian]

Richard--would any of these work with my '04 C4S which has the MOST fiber optics? If yes, which one would you recommend for my final attempt to hardwire an FM modulator for my iPod? And could you tell me where it should be wired...

Thanks,

John

Edited June 8, 2005 by bavarian

[alprus]

The humming or whining sound usually is a result of a grounding problem. I would try to move the ground wire to a new spot.

[Thanatos69]

Bavarian,

I haven't had much experience (AKA none what so ever) with the MOST bus radios, but I believe they do not accept the analog inputs that would normally be used on the older versions. (Anyone, if I'm wrong, please correct me) So you're probably looking at having to use the FM modulator until someone releases an analog to digital converter for the MOST bus.

The best FM modulator to use I think would be an inline unit. It would feed inbetween your antenna lead and the antenna in connection on the radio. An inline FM modulator will block out the actual antenna signal while its in use. Because of this, you'll have less 'bleed over' from any radio stations that might be broadcasting on the same FM channel you're using for the modulator.

With a setup using an FM modulator, I might recommend using both types of filters. You'd be using the inline audio filter from the IPod to the FM modulator. Then you'd also be using an inline power filter for the power connections on the FM modulator.

The whole point of both types of filters it to remove or damper certain frequencies of EMI (ElectroMagnetic Interference). Its possible you might lose some audio clarity from the filters, (mainly highs and sub 60Hz lows) but they should help to reduce the overall line noise.

If anyone else wants to add to this, please do as its been a while since I've even attempted to install any form of car audio. It use to be a big passion of mine back in the mid to late '90s so I might be a bit rusty on a few things here and there.

[Izzy]

Bavarian,

I haven't had much experience (AKA none what so ever) with the MOST bus radios, but I believe they do not accept the analog inputs that would normally be used on the older versions.  (Anyone, if I'm wrong, please correct me)  So you're probably looking at having to use the FM modulator until someone releases an analog to digital converter for the MOST bus. 

The best FM modulator to use I think would be an inline unit.  It would feed inbetween your antenna lead and the antenna in connection on the radio.  An inline FM modulator will block out the actual antenna signal while its in use. Because of this, you'll have less 'bleed over' from any radio stations that might be broadcasting on the same FM channel you're using for the modulator.

With a setup using an FM modulator, I might recommend using both types of filters.  You'd be using the inline audio filter from the IPod to the FM modulator.  Then you'd also be using an inline power filter for the power connections on the FM modulator. 

The whole point of both types of filters it to remove or damper certain frequencies of EMI (ElectroMagnetic Interference).  Its possible you might lose some audio clarity from the filters, (mainly highs and sub 60Hz lows) but they should help to reduce the overall line noise.

If anyone else wants to add to this, please do as its been a while since I've even attempted to install any form of car audio.  It use to be a big passion of mine back in the mid to late '90s so I might be a bit rusty on a few things here and there.

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