Recently heard a loud buzzing (?) sound from 2004 Camry. Was quite loud but mysterious but have discovered (I think), that it comes from the driver's side radio speaker......frequency is rather low. At first, it appeared to be on FM radio and would come and go and could be eliminated by switching to AM. However now it appears to be more constant and is present on both AM and FM and also if I push the tape and CD buttons. Any ideas? Who best fixes radios? Auto repair shop or one that specializes in radios?
Hmmm--intermittent, low frequency, from one speaker only, in a door speaker (?): I'm gonna suggest you might have a torn speaker cone. It could also be a lot of other things, but this has the advantage of being easy to check and easy to fix, if you can get at the speaker.
Can you remove the speaker grill or look through the grill to see if the speaker cone (the big membrane that vibrates and makes the sound you hear) is intact? They often tear with age, especially in door speakers or ones in the back deck (due to pressure changes from the closing door/trunk) or when exposed to the sun (back deck or dashboard). If it is torn and you can get at it, the easiest solution is to simply replace the speaker with another one of the same size and impedance (omage--marked on the back). If it is not torn and if you can get at the back of it, re-seat the contacts on the back and see if that fixes things.
I don't know if anyone actually repairs the radio units themselves anymore. If there's something wrong with the circuitry, it's usually cheaper to just get a replacement unit. If you absolutely want to have everything look stock, then a replacement radio from a junked Camry would be the easiest fix. The cheaper and more reliable answer would be to get a new unit at a local car stereo shop (or Best Buy) and have them install it. You could even upgrade to new features (front input for your MP3/Ipod?).
I try to do anything before tearing into the dashboard myself. Hidden, fragile clips, brittle plastic, lots of little pieces, cramped working conditions: the projects always take longer than I think they should and typically involve some amount of "improvisation" (gum, epoxy, making new parts, etc) and swearing to get an acceptable result.