# Re-Foaming AR-58bs Advice



## FireWalker877 (May 14, 2007)

Hey guys,
A girl I've been dating mentioned that she had a couple of floorspeakers in her closet taking up space, and told me that she wanted to get rid of them. Naturally, I jumped at the opportunity. So I pulled the two 50 lb behemoths out and removed the grilles. All kinds of deteriorated foam fell out on me. :sob: Everything else appeared to be in decent shape, with only a tiny bit of cosmetic damage. Turns out they're AR 58b's, one of Acoustic Research's last decent models.

So here are my questions:
Has anyone here refoamed a similar speaker? Should I do it myself, or have a shop do it? Does anyone have a favorite place to purchase new surrounds? Any advice?

Thanks,
Charlie


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## FireWalker877 (May 14, 2007)

Wow, I just saw that drf posted about this very topic over in DIY. I am still wondering whether or not I should have a professional do the job. Also where can in find rubber repair kits in the US?


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## drf (Oct 22, 2006)

If you are careful and follow the intructions you should be fine. It really isn't as complicated or hard as it looks. Remember, so long as your carefull and don't cut the Vc leads when removing the dustcaps and don't damage the cone, any mistake (low chance) and a professional re-coner should still be able to fix it.

good luck with it either way.

Drf


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## Wayne A. Pflughaupt (Apr 13, 2006)

Typically I don’t even mess with the dust cap. It’s not hard to center the cone on the VC by feel.

Here’s a link to a guy on eBay selling surrounds for those specific speakers.
http://cgi.ebay.com/AR58b-Speaker-F...ihZ008QQcategoryZ3276QQtcZphotoQQcmdZViewItem

Regards,
Wayne


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## FireWalker877 (May 14, 2007)

Thanks, Wayne! I was wondering if I could manage to avoid cutting those out. One of the caps is punched in one one of the woofers, are there any tricks to fixing that? I wonder if I could pull the dent out with a strip of tape? I've never done any speaker repair since I've never really had a need to. At least until now. Thanks again for your help!


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## Wayne A. Pflughaupt (Apr 13, 2006)

> I wonder if I could pull the dent out with a strip of tape?


That works more oft than not.

The way I center the cone on the VC is first install the surround to the cone, then (the next day, after the glue sets) apply the glue to the bottom edge of the foam (that will attach it to the frame). After you do this, you can move the cone left and right, and for and aft to see where it hits the VC. Then you can center it between those parameters. I’ve done it several times, and only once did I mange to end up with the VC rubbing. Unfortunately, that required a complete "do -over," but I got it right the second time. 

Regards,
Wayne


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## drf (Oct 22, 2006)

Wayne A. Pflughaupt said:


> That works more oft than not.
> 
> The way I center the cone on the VC is first install the surround to the cone, then (the next day, after the glue sets) apply the glue to the bottom edge of the foam (that will attach it to the frame). After you do this, you can move the cone left and right, and for and aft to see where it hits the VC. Then you can center it between those parameters. I’ve done it several times, and only once did I mange to end up with the VC rubbing. Unfortunately, that required a complete "do -over," but I got it right the second time.
> 
> ...


:hail: You have the Zen touch. I wouldn't even think about doing it without shims. 

I guess that explains why I won't even put a dollar on the horses, I am not one for taking risks. 

when you had to re-do the surround, could you re-use the surround or did you have to buy anotherone?


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## lcaillo (May 2, 2006)

I mostly do them without shims, and I do quite a lot of them as I repair electronics for a living. I am not a speaker pro by any means, but a do a few dozen refoams a year. The problem with shims is that you assume that the spider was attached perfectly and is perfectly uniform, that the cone is perfectly uniform, and that the surround is perfectly uniform. When you do it by feel, you can account for any combination of these. Also, it is easy to get debris in the gap which can cause noise or scraping. Always blow out any dust or debris and pass a business card or piece of paper through the gap to be sure that it is clear, before putting the dust cap back on if you do use shims.

Always attach the surround to the cone and let it cure, first. A good trick to getting the coil centered in the gap is to take a smaller driver and set it in the cone upside down to hold the cone down in the gap and let the spider center it. This lifts the edge of the surround up off of the basket and you can run a bead of glue around under it. Use a slow drying glue (my favorite is WeldBond), and as it gets tacky, remove the weight from the cone and tamp down the edge of the surround. It will be pretty well centered, but you need to check the travel of the coil in the gap. You should be able to push down on each side of the driver and get clean travel. If you can't the side that scrapes when you push on it is too close and you need to shift the position of the surround on the basket. A slow curing glue lets you do this with no problem. Once you get it where you want it, clamp the surround down with clothespins (special speaker refoaming surround clamps...I sell them for $65 for two dozen with a special anti stick coating for any of you who are in need of a snake oil treatment).

Check the travel again before the glue sets to be sure you have the coil centered in the gap.

I just did a velodyne woofer and used shims because it is easy to take the dust cap off as they use hot melt glue. You also have to verify that the accellerometer on these is not loose nor the wires to it because they will rattle sometimes. While I had it open we shimmed it. Put it together and guess what... a buzz. Went back and re-installed the surround without shims and it was OK.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Had to buy another one. 

Regards,
Wayne


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