Car Stereos: Car Speaker Noise, toyota avalon, noise question

Question
QUESTION: I have a 1998 Toyota Avalon and the speaker and tweeter in the drivers side door are working but making a heavey static noise after they are on for a few seconds.  Start out fine but after a few seconds beging to emit a static noise.  It is all factory installed equipment.  I have disconnected the speaker and the noise still comes from the tweeter and the same thing happens when I disconnect the tweeter, the speaker still emits the noise.  I am baffeled unless the channel to the door speaker and woolfer is bad and if that is the problem I guess it could cost a lot to fix.  I don't want to replace the speaker and twweter and then findout it is a bad radio.

ANSWER: Jerry, I would assume the problem is either in the radio or the wiring.  If it were the speakers, the static would be all the time.  I would start by checking the wires going through the doorjam.  It is a common place for wires to wear thin and start shorting along a sharp piece of metal.  If all the wires look like they are in good shape, then I would guess the problem is internal.  Usually, an internal radio problem can be repaired for less than $100 at an electronic repair shop.  Hope this helps, Scott

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QUESTION: I pulled the door panel and can see the speaker membrane is separated all the way around the outside edge and I would like to know if that is the way it is supposed to be?  In other words the outside edge of the black membrane is not attached to anything, it is totally disconnected.   When I unplug the speaker and tweeter the background noise goes away and the other speakers work fine.  Toyota want almost $300 for the one speaker and there is no way I am going to pay that much for a speaker for an 11 year old car.  I guess, I can just leave that speaker disconnected.

Answer
Jerry, There are aftermarket speakers that will fit in the factory positions.  You can go to crutchfield.com and fill in your car, and they will show you what speakers are available for your car.  Also, If you go to your local mobile electronics store, they can show you what speakers will fit your car and they will mount them for around $30 - $40.  You are correct in assuming the speaker cone is supposed to be attached around the edge.  Since it is not, the internal coil is being pulled against the magnet and causing the short which is causing the humming noise.  I would, definitely, keep the speaker disconnected until you get the new ones installed.  great investigation!  Good Luck, Scott