StimpyWan
Addicted Member
I believe it is a 3M tape. I'll double-check when I get to work tomorrow.
AR Tweeter Diaphragm Replacements (AR12s)
- Thread starter turnitup
- Start date
I believe it is a 3M tape. I'll double-check when I get to work tomorrow.
Just quickly touch the battery leads. Don't hold them on long. You just want to see which direction it bounces.
turnitup
No, the stereo won’t break the crystal...Oh CRAP!
Learned very early on that “3M Super 33+“ was the ONLY electrical tape to use. My friends were electricians…. Also set me squarely on Klein tools. I have some tape that is probably over 35 years old that is still like day 1 fresh. Amazing stuff, but there is probably more appropriate for this tweeter project. Just keep me in mind! Thanks my AK friend!
Kapton has specific properties. It's very heat resistant, good electrical insulation, and it's orange. Years ago I made ribbon speakers with it. Since it's a tape with adhesive, I cut narrow strips of aluminum foil and stuck them onto the Kapton. 4 rows of foil onto a 1/2" wide tape, 3 feet long. Suspended it between two rows of magnets and voila, a ribbon speaker. It worked really well sound wise but was a fairly low sensitivity.
Good luck with your tweeter repair.
John
Good luck with your tweeter repair.
John
Years back now wife was going to a big box store and told her to pick me up a good o roll of 3m. She called and was asking if such and such would suffice. The guy helping her said it is all the same anyway.....
She knew better, he just would not let her alone. You know the type....
Called to have me tell him he was mistaken. They had it just twice the price as the junk rolls.
StimpyWan
Addicted Member
As mentioned, it is Kapton tape. Great stuff, very robust and heat resistant. We buy it through McMaster-Carr.
It’s a shame these diaphragms are being stated to be direct replacements for 3a type tweeters. They fit the hole, but sound nothing like how the original tweeters should sound. I’ll leave it at that. I will elaborate on a drastic difference in sound when using these diaphragms on AR12, AR9 style tweeters. Very different sound as well. The original AR12/9 diaphragm is more of a true hemisphere, and has a much less compliant suspension section, adding more dampening to the diaphragm. These Replacements will get your tweeters making sound again, but the Midwest replacement is a much better way to go for 12/9 types. Now if someone can source where the Midwest tweeter’s dome/coil is coming from, that is the move.
turnitup
No, the stereo won’t break the crystal...Oh CRAP!
That’s disappointing to hear, but can’t say I am surprised to hear your assessment. I’m committed to the restore as the parts are already on order. The investment was significantly less than the new complete Midwest driver replacements, so thought I’d try the lesser of the two evils first. Is you assessment based on first hand experience with the replacement diaphragms from the auction site? Just curious...thanks for your post.
Hi, I don’t want to sound negative, I am stating my first hand experience. Comparing these aftermarket domes when installed in AR tweeter bodies, with and without ferrofluid, to good functioning AR9, AR9ls, AR10pi tweeter examples, I do note very different sound characteristics. Options on restoring early AR tweeters and speakers are very limited so things like this can get you past an obstacle. I do feel more work is needed in the dampening department or crossover mods to get these domes sounding close to the originals.
turnitup
No, the stereo won’t break the crystal...Oh CRAP!
Negative or not, I appreciate the input. There are very few AR12s out there, and even fewer people experienced in repairing the rather unique 8 ohm tweeter versions. Many of the soft dome tweeters have dampening materials installed under the domes. I wonder if adding a small amount of poly material underneath the dome would help in stiffening/dampening the tweeter? Obviously a very subjective/unscientific approach, but wondering, none-the-less. The dome already has a wooden “button” glued to the housing beneath the dome (I assume to dampen, and possibly protect from crushing fingers?). These tweeters are some of my favorites, so disgusted that I caused the ruin of these in the first place, but such is life...
StimpyWan
Addicted Member
While not an AR tweeter, RoyC often comments on AR dome rebuilds, at CSP. Roy has mentioned that the dome midrange drivers do use a poly type material under the dome. But, be careful not to use too much, as he has found locked-up domes, where the poly material worked it's way into the voice coil gap.
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turnitup
No, the stereo won’t break the crystal...Oh CRAP!
While not an AR tweeter, RoyC often comments on AR dome rebuilds, at CSP. Roy has mentioned that the dome midrange drivers do use a poly type material under the dome. But, be careful not to use too much, as he has found lock-up domes, where the poly material worked it's way into the voice coil gap.
Very good point, I think I have seen almost styrofoam like material used on some very old AR tweeters, but the possibility of the poly material working its way into the coil didn’t cross my mind!