The stereo in my 2001 Tahoe started sounding pretty badly, and I thought there was a problem with some of the door speakers, but there wasn't.
Background: 2 or 3 years ago the stock radio/CD machine quit working, and on a Black Friday deal from New Egg.com, I bought a Clarion with a USB port on it, that has a DSP chip that allows for all sorts of subwoofer volume, crossover frequency adjustments via changing crossover points of both high and low-pass filters, many parametric changes and tonal adjustments are available on this CD/radio unit, and I think it has 50W X 4 channels...$75.00 and head-and-shoulders better than stock. I just set it up as well as I could when I got it and forgot about it.
Recently, being aware there was trouble in 'paradise", I got a quiet moment, put on some moderately punchy music, and discovered that the distortion I was hearing was from the subwoofer (and not any of the door speakers) which on the '01 Tahoe, is in a little molded plastic box on the driver's side of the vehicle back behind the Left rear wheel. The big round grill was a giveaway to the location!!
The rear door sill, the trim under-the-window, and the little vertical back corner trim pieces have to be pursuaded away from their normal locations to gain access. Unscrew the cargo net stud. The stock woofer was deteriorated, pieces of the surround lay in the bottom of the enclosure, and the cone was flapping wildly, sort of like a chicken with a wrung-neck, hence the distortion.
After some research, I found that it took an 8" sub to replace it. I got a low profile or reduced height 8" JBL subwoofer the GT 804, from Amazon.com for nearly $50.00 shipped, (30 bucks cheaper than Crutchfield) and put it in. The difference between the two speakers was like a Mercedes and a Yugo. The short of it is that it fixed all the radio distortion problems and the bass now sounds great, very high-fidelity. I am an audiophile and have almost exclusively Klipsch speakers and Crown amps biamped with electronic crossovers(5 stereo power amps, 20 drivers) in my home system so I know good and this sounds good.
Installing the new sub was rather straightforward. It fit in the box well, just clipped off the old terminals, stripped the wires, and screwed the corresponding wires down into the 5-way binding posts, plugged the old mounting holes (for a flange slightly larger than the original speaker) with their old screws so there would be no whistling or "chuffing" from the back of the sub through the edges of the enclosure, and took self-drilling screws and mounted the woofer to the front of the box, from the outside, centered in the available hole. The new sub comes with some foam with a single-sticky side, and I ringed the opening with the foam before I mounted the subwoofer, to seal vibrations in and stifle any possible rattling. You would start these screws fast then slow down to avoid stripping, and save the step of drilling a bunch of holes. After I got it installed, replaced all the trim, then took to the front seat for an adjusting session...now it's all good.
I wouldn't waste a dime of YOUR money on any genuine GM speakers...if you go to the website of Parts Express (an outfit in Ohio) and get the cheapest pair of 6.5" speakers you could find the pair of them would be better in quality than what is in there now, and probably half the price. Even if mismatched it would still sound better if you just replaced the one. Do some price comparison at Amazon.com too.
The main reason I like Parts Express is they sell an EXTENSIVE inventory of speakers and publish the Thiele and Small parameters for everything they sell, have excellent customer service and technical support, and are dedicated to the audiophile community. That's good, but I'll still save $30.00 if I can...
Good luck with fixing your audio system...
