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Complete Refoam Project Finished.


Doug G.

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I have a total of five pairs of woofers for large Advents. Three of these are in the speakers that make up my triple stack and two are spares. One spare pair are masonites and the other are all-metal woofers.

These woofers have had, until now, a variety of surrounds installed on them. One of the pairs in a set of utilities I bought had had them replaced and the job was top notch. Unfortunately, whoever did it used surrounds that were way stiff. It was actually fairly difficult to push the cone down even in free air.

Another pair that were in the walnut versions I have were the all-metal ones that, I determined, were replacements because the originals in this particular pair (made in August of 1975) would have been masonites. Again, these had been refoamed sometime with too-thick surrounds.

I had previously replaced the surrounds on the third speaker pair with surrounds from Woofer Repair and, while they were better than the other two sets, I later discovered that they too were not exactly correct.

So, about a month ago I decided to completely replace all of the surrounds on the three pairs that had the stiff surrounds. I had already bought two masonite woofers and got surrounds from RSSounds last year for the walnut pair. The all-metal pair then was the spare pair.

So, earlier this month I got the fifth pair off eBay and refoamed them with surrounds from looneytune2001, taking the chance that they would be correct. They were. Just like the ones from RSSounds. By the way, it appears that currently, RSSounds do not sell surrounds.

I was then able to sub in this fifth pair in the triple stack while the originals were out for refoaming.

I finally completed all of the surrround replacing today and am satisfied that all of them are now performing to spec.

I know that the trapped air (spring) is dominant in an acoustic suspension system and that the final performance of the system may not be affected that much by the different stiffness surrounds but it bugged me that the woofers had the incorrect surrounds. OK, so I'm crazy :^)

Some notes:

I actually had to partially rebuild one woofer that was buzzing with a low frequency (30Hz) fed to it. I unglued the spider, removed the cone assembly, and found that the yellow tape between the former and wires was loose on one side. I glued this tape down and reassembled.

I found that the original Zip-Strip brand finish remover works very well to soften and remove all of the different adhesives that had been used on these woofers, even the later "white glue" types.

I pretty much used the conventional method to attach the surrounds to the masonites (attached to the front/top of the cone first and then to the rear of the masonite ring).

On the all-metal pair, I actually attached the surround to the frame first and then held the cone up with rags to allow space to apply glue to the inner lip of the surrounds and then let the cone back down onto the surround. It worked very well.

I did not use shims at any stage. The cones, already held in place by the spiders, pretty much find their own place with just a little work to be sure they don't rub. On the one woofer I had to disassemble, I just eyeballed the gap with no dustcap in place.

I still get amazed by these speakers sometimes when a really good source is played through them!

Is this post long enough? :^)

Doug

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How did you wire a triple stack?

How do you keep them from falling over?

What tweeters are you using?

What amplification are you using?

I have a single pair of walnut Advents. The only knock I have is a harshness in the tweeter. I bought a pair of black tweeters but have not tried them yet. I have also heard that double stacked Advents are a vast improvement over a single pair.

I have AR3a's and they are sweet at the top so it's not my front end. Maybe it's bad synergy.

I will be looking forward to your response.

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Hi Stan,

>How did you wire a triple stack?

Each pair has its own Heathkit -29 series amplifier. One in the form of the AR-29 receiver and two in the form of the AA-29 amplifiers.

>How do you keep them from falling over?

They seem to be steady enough. There are no children to knock them over :^) Mine are all grown and gone :^(

>What tweeters are you using?

The original fried eggs that came in them.

>What amplification are you using?

See above. Rated at 35 watts per channel but realistically 50.

>I have a single pair of walnut Advents. The only knock I have

>is a harshness in the tweeter. I bought a pair of black

>tweeters but have not tried them yet. I have also heard that

>double stacked Advents are a vast improvement over a single

>pair.

This harshness seems to be something some hear and others not. I don't seem to have a problem with them. Some have stated that they like the later black domes better. I haven't heard them.

I think that the stacked configuration is vastly superior than a single pair in spite of some expert opinion that phase interference between drivers should be audible. If it is, I don't really notice it. They sound very smooth. The bass is incredible with the right source.

>I have AR3a's and they are sweet at the top so it's not my

>front end. Maybe it's bad synergy.

Who knows? I haven't heard AR3as but I have heard 10pis and they were also incredible speakers.

>I will be looking forward to your response.

I would get another pair and try 'em stacked. I think you'll be pleased.

Doug

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Guest SpruceMoose

survey says..... stack 'em!!!

or build up some custom cabinets to get the look you like and stash the original boxes.

post-100436-1181150237.jpg

post-5-1181150237.jpg

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Nice work Doug!

I'd just like to suggest that next time you do a spider and you already have the dust cap off,

a business card cut into strips

usually works well for shims.

The tip to use original Zip-Strip brand finish remover to soften the glues is the same way I

did it probably 30 years ago. I'm wondering if you were able to get the dust cap off by

softening the glue or did you cut it off?

Again, nice work!

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Thanks for the responses.

The logical thing for me to do is get another pair, stack 'em and then listen for a while and see where that takes me.

The Sprucemoose single cabinet solution looks like the best of all scenarios with regard to the end result.

This should be fun.

Thanks again all.

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Thanks Pete.

With a little patience, I was able to get the dust cap off with the Zip-Strip. I just used several applications until the glue let go. It didn't hurt the cone at all.

The dust caps on this pair of woofers were not the originals and were of hard paper. I removed the other one too and replaced both with cloth caps.

I think it has been mentioned before that the size of the dust caps probably doesn't matter much, as far as sound is concerned, if they are of the cloth variety but hard paper or other hard materials may affect the upper range of the driver.

Doug

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