68-69 Radio Speakers

[Chuck G.]

Just received a pair of radio speakers from Mid America. They are advertised as "original". These are the speakers that mount in the kick panels, not in the dash. The aftermarket speakers that I removed because they were "buzzing" were 4"x6" in size with a mounting bracket on the bottom. The new speakers that I received are 4"x10" in size, also with the mounting bracket on the bottom. They are huge in comparison to what I removed. I looked in the AIM, and it looks like these might be correct, comparing the configuration pictured in the AIM. It looks like they will fit too, but I thought I would ask. I also noticed that the "perforations" in the kick panel extend fully to the top of the panel, and these speakers will fully cover the perforated area. Any thoughts ? I don't think I've ever seen an original 68-69 speaker. I'm more familiar with solid axles and midyears. Any help will be appreciated. Thank you. Chuck Gongloff, Baltimore, Maryland

[Chuck Watson]

Re: 68-69 Radio Speakers

I have a 1969 Radio Service Manual for Delco Radios and it shows the speaker to be a 4" x 10". But Rick Bizzoco's book "1969 Stingray Guidebook" calls them out to be 4" x 6" for a 1969. I've also got a complete radio including speakers out of a mid 1969 car that has 4" x 10" speakers.

Chuck W. NCRS #31154

[Joe L.]

Re: 68-69 Radio Speakers

The kick panel speakers, GM # 7307181, originally used in 68-69 Corvettes were approximately 4"X10". These speakers were designed so that the magnet and protruding cone section of the speaker fit into the recess in the kick panel. They were attached to the kick panel by a strap which was rivetted to the bottom section of the speaker and attached to the car's sheet metal via 2 self-tapping screws. This speaker configuration was used only on 68-69 Corvettes; later models had the speakers relocated to the upper dash panel, although the kick-panel speaker grilles remained.

The 68-69 speakers were of 10 ohm input impedence to match the 10 ohm output impedence of the radio. If any alternate speakers with significantly different impedence ratings are used to replace the factory speakers while retaining the stock radio, the input impedence of the speakers should be matched to the stock units to avoid damaging the radio. Most modern-day speakers are of 4 or 8 ohm impedence. 8 ohm speakers will work ok, as is, but 4 ohm speakers need to be impedence matched by adding an appropriate resistor to the speaker circuit. Probably more than you wanted to know, but, since I was on the subject, I'd thought I'd provide some information which might be useful to others.

[Chuck G.]

Re: 68-69 Radio Speakers

Thanks, Joe. I was surprised when I opened the boxes. I tried to order a pair of originals from GM, as I was told they were still available, but when I went to my GM parts "guy", he told me they were discontinued. I can't find any impedence written anywhere on these speakers, so I'll have to assume that it's correct. My "old" speakers were 4x6 Auto Custom Sound units that were "buzzing". I had the radio gone over this winter and it was OK. Thanks for your input. Chuck Gongloff

[Chuck G.]

Re: 68-69 Radio Speakers

Hello Chuck; Thanks for your help. It looks like the 4x10's are OK. I really don't care about originality here, I just wanted/needed a pair of speakers that didn't crackle and hum. I was surprised when I opened the boxes and saw the size of these speakers, compared to the 4x6 aftermarket units that I had removed. Thanks again. Chuck Gongloff, Baltimore, Maryland

[Chuck G.]

Re: 68-69 Radio Speakers

Hello Chuck. Thanks for your input. I removed a pair of 4x6 aftermarket speakers that were buzzing and humming. (radio is OK--just got it back from the repair shop). I was surprised at the size of the speakers that came from Mid America, but it looks like they will fit, and it looks like that's what belongs there. I'm not REAL concerned about originality here, I just want a pair of functional speakers that work. Thanks again. Chuck Gongloff

[Jack H.]

Re: 68-69 Radio Speakers

I've got a hunch one reason for moving the speakers from the kick panels was sound focus (use windshield as a reflector at ear level) and another may have been reliability. Seen a number of older Sharks with water leakage into the bird cage opening behind the kick panels and these were paper cone speakers.

Might want to consider a form of vinyl plastic protective coating for the backside.... If you do, be sure to devise a mounting method (RTV?) that will prevent it from losening, flapping, buzzing.

Last, the original 4x6 out of my '71 dash had rubber stamps and I recall they read 32 ohm. If I'm right, standard off-the-shelf 8 ohm replacement jobbies aren't matched for optimum power transfer coupling to the radio's output drive transistors....