Weird floor noise through subwoofers with Alpine MP3 CD Changer. Alpine PXA-H100 Suspect.

[DAN831111]

Hi I have a new Alpine MP3 CD Changer and it makes knocking thuds whenever it is changing through discs and a consistent "bassy" whurr through my twin Alpine Type R's when its playing a cd. It seems to only do these sounds out of the subs.

The Cd Changer is connected via Ai-Net into an Alpine Imprint box which comes out of my Alpine INA-W900E Head Deck. My 3 Alpine v12 Amps all run out of the Imprint box. I have tried changing RCAs on both mono amps (which run the 2 Type R's) and no difference, and it plays the noise through both amps. As soon as I flick it over to the headunit CD player or anything else like radio or usb the noises are completely gone, only does it when cd changer is in use, it can be still connected and makes noise just when its operating. Unplugging it does nothing.

The imprint box is what I suspect? It is grounded in the same location as the head unit right behind the head unit. The CD Changer is old but was never used brand new out the box.

 

Any ideas? Is this type of noise problem common for PXA-H100 Imprint devices?

[DAN831111]

something to do with the bass knob that comes off the rcas off the imprint unit, if i turn it to 1/4 or above half way the noises stop. I need the bass knob, it cant go no matter what and its not possible to run a bass remote knob directly from the amp (well you sort of can via Amp-Link directly to a compatible head deck).

 

Also it turns out this problem is not as bad in the daytime with ambient noise around as it was late last night, when the cd is playing it doesnt bother that much, even in silent bits, but still something I must get rid of if I can its just annoying, my SQ is going down the drain with noises like this. 

 

Any ideas why this is happening or how to fix it, I already tried turning my gains down a little and basically nothing happened. Is it because the Bass Knob is just a cheapie from eBay, will buying a better one help?? Any opinions are warranted.

[Dafaseles]

Try disconnecting the knob all together. If the sound goes away, then that seems to be the problem right there, then you can replace it with a better one. 

[DAN831111]

yeah its definately the knob, would that rockford fosgate plc-u one be problem free, thats the only one i can get thats decent from here. we cant order from sky high or anything like that from here

[Dafaseles]

59 minutes ago, DAN831111 said:

yeah its definately the knob, would that rockford fosgate plc-u one be problem free, thats the only one i can get thats decent from here. we cant order from sky high or anything like that from here

Rockford Fosgate stuff is pretty on point. It's definitely worth a try in my opinion