Posted 26 January 2012 - 08:07 PM
Posted 27 January 2012 - 12:35 AM
Posted 27 January 2012 - 12:49 AM
Posted 27 January 2012 - 07:23 AM
Posted 27 January 2012 - 02:03 PM
Posted 28 January 2012 - 12:33 AM
Posted 28 January 2012 - 02:41 AM
Posted 28 January 2012 - 11:37 PM
Here is MSound's how-to for refoaming speakers.
It takes some patience and a steady hand but it is NOT difficult. As mentioned, John is very helpful. His kits are very complete--right down to alcohol swabs. There is a link to his ebay store on the bottom of the page. Please note there are 2 different replacement foams, one of which he describes as "improved." I'd take his word on that.
Regarding your tweeters, the problem may very well be the pots and not the tweeters. If you read the AR3a restoration guide, pinned to the beginning of the AR section, it will tell you how to clean the pots or (better, IMHO), replace them with $5 L-pads.
If you do have a bad tweet, the HiVi replacement suggested is excellent. But is it "better"? That's a matter for debate. The HiVi is a modern design with ferrofluid cooling. It sounds good and is rugged, so it will stand up to loud music. The original was (is?) and excellent tweeter, known for its smoothness and dispersion. But it's old and does not age well.
So, purists will insist on original tweeters but they are reaching the end of their useful lifespans and even if you find a working used one, it could be dicey. My bias is in favor of the HiVi tweets and the new L-pads. YMMV.
Posted 29 January 2012 - 05:11 AM
Posted 29 January 2012 - 05:06 PM
As you know, there are differences of opinion on shims, but I go with MSound's advice and do the shimming. Read page 2 of his instructions. There is a topic, Speaker Clearances & Why We MUST Use Shims. Note that there are about a dozen pages and 28 photos in those instructions. Very thorough. And he sends a printed copy of the instructions with the kit.
The dust caps are not hard to remove--just use an x-acto knife or razor blade and follow the instructions. The kit comes with new, slightly larger caps. And no--they are not inverted, so yours are pushed in and that's more reason to replace them.
It's not hard. I like to say that if you ever built a plastic model you can refoam a speaker (assuming the model turned out looking good--not all glopped up with glue). Give it a try. My first re-foam project was a pair of AR2ax's. I bought the MSound kit and followed the step-by-step instructions to the letter and the job came out perfect. Photos of that project are here: http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_pictures/ar-2ax_pictures_from_jkent/ OTOH if you are really nervous about it, send the woofers to a pro such as Millersound in Pennsylvania or Carl's Custom Loudspeakers in Connecticut, or contact MSound. He also does refoaming. The cost is probably about $70 to have a pro do it, plus the 2-way shipping. It will be done right and they will be tested before they're returned to you.
Posted 29 January 2012 - 09:05 PM
I have also bought re-foam kits from MSound. He puts together a great kit and is very helpful. I'm a believer in shimming. It ensures that the coil is not only going to not rub but that it is aligned properly as it moves. (I hope that sentence made some sense!)
Posted 29 January 2012 - 10:38 PM
Posted 29 January 2012 - 11:04 PM
There is nothing to be nervous about if you can handle an x-acto knife. Follow the instructions. Slice the cap off then cut the shims into strips and slip them between the VC and pole piece. There is enough clearance that it's no problem. Insert them at the 12 o'clock position, then 6, then 9, then 3, as shown in the attached photo. The fit should be snug enough that you can position the cone up & down and the friction will hold it. When all done, remove the shims and vacuum, then glue on the new cap. Just follow the instructions. No biggie.
im a little nervous to mess with the voice coil and shims but maybe its easier then i think it is.
Yes. First things first. You can test the tweet of course, but you absolutely should replace the old wax capacitor with new film caps--one 6uF and one 4uF per speaker. Then check the pots. They are probably cruddy. Many people have success cleaning them and coating with dielectric grease, but IMHO an L-pad is much better (2 per speaker). They will be brand new and will not corrode. They cost about $5 each from Parts Express.
i was told the other tweeter though not working may be just the crossover not sending a signal.
If you do need tweeters, be aware that some were "front wired" like mine (in photo) and some were "back wired." If you get the Hi-Vi replacements you should buy 2, and it is no problem using them as-is (back wired). You "can" modify them for front wiring if you want, but cross that bridge when you get to it.
Posted 30 January 2012 - 07:10 PM
Posted 31 January 2012 - 09:38 PM
The original dust cap can often be retained by simply slicing around its perimeter with an exacto knife, and flapping it back for shimming. When the re-foam is complete, glue it back down.
Posted 01 February 2012 - 06:07 PM
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