Well, I took her apart. Boy does a lot of dust accumulate in those things after 20 years!
I saw 2 speakers and 2 parts to each speaker - the LFD and the tweeter. Two cables were running out from each and all 4 combined to one cable to run into the main board. The part numbers were as follows:
Tweeter - 1-503-486-11 ($20.04 from Sony)
LFD - 1-503-538-11 (Discontinued from Sony)
I tested out the sound again, and sure enough it was the low frequencies - just my luck! Since the wires were soldered in the LFD, I probably couldn't have replaced them anyways.
I decided to (carefully, as not to get shocked) remove the left speaker's wire from the motherboard's connector. After turning on the TV, the right speaker still made the rumble, but not as bad. So I'm guessing both speakers have the problem, but the left one is worse.
As a temporary solution, I've disconnected the white RCA cable so only the right speaker works. I know this would probably freak out all you audiophiles, me only having mono sound, but my old ears can't tell the difference
I have some external Bose speakers from a radio, but they have speaker wire instead of the RCA jacks. I assume I have to purchase an AV receiver to get these to work, but the cheapest one's I could find were $200. They all were for surround sound systems. I'll be looking at my local pawn shop tommorow for some cheap ones. Does anyone know of any that are cheap and just run 2 speakers, or a device that's similar that does the same job?
Thanks!