Door speaker knocking sound
 

My stereo plays quite well, but when I play a particular song (Blowout by The Crystal Method - can listen here if you wish, accompanied by some average mountain biking) there is a knocking sound from the driver's door speaker about every 8 beats when the bass drum hits. It sounds like if you knock a knuckle on a wooden desk and stands out alot from the sound. I know listening on different systems, such as headphones, gives a different sound (and is part of the fun), but this is just weird.

That's the only song I've heard it in, so I don't play that song any more because I don't want to think that my beautiful car is broken. :D

Can anyone tell me if that indicates that the woofer is shagged? And is there a definitive way to test it?

Thanks,
Sandy.

I am in the process of replacing all my speakers except door(for now) see link below. The doors in most are a mini subwoofer. You can play with your eq settings(depending on stereo). The speakers in Boxsters are garbage!! (at least earlier versions). You could have very well blown a speaker as I believe the amp is hooked up to the fronts and doors or you could have your bass up too high. Did it happen before with the same song or is this the first time you played that song?

http://www.987forum.com/forums/showthread.php?t=21452

I doubt if your speaker is blown if you can only hear the noise in one song.

There is a plastic housing around the door speakers. If you take the panel off the door, you'll see this huge contraption that I can only guess the thinking was to deliver better sound. More than likely that housing is loose and is rattling.

My dad had the same thing happen on his 996. Popped the door panel off and removed the plastic housing because he had replaced the entire system and the housing wasn't needed anymore.

Thanks
 

Thanks for the answers. :)

It's weird. There must be just one particular frequency in that song that does it.

From memory, the bass and treble are both +2 (on a CDR-220). The bass and treble were on +7 when I picked up the car two months ago.

As suggested I'll try playing with the equalizer settings a bit, and also the fade to see if the passenger speaker does it too.