Replacing foam surrounds

[Pure_Brew]

I've done a bunch before but always I removed the dust cap to shim the voice coils.

I'm thinking I might start to work on these old vifa 8" drivers that came with the Snell EII.

However, I am seeing these replaced without removing the dust caps. Looks like you can attach the surround to the cone first, allow to dry, then clip the surround to the basket and check for rubbing of the VC.

I suppose I can check for VC rubbing by hand, or even use some low frequency to get some travel.

Anyone ever do surround replacement without shimming the coil here?

 

[Pure_Brew]

Ah well nvm, I just bent the cone pretty badly and chucked them in the dumpster lol.

They were pretty awful looking anyway, looking like moisture/sagging got to em which you could see on the spider and the magnet had corrosion.

 

[dingus]

well fwiw, my first surround replacement job was on some large advent's and i didnt shim them. never any issues as a result, but it takes a bit of luck to get them right. shimming takes all the guesswork out of the procedure and i wouldnt replace surrounds any other way.

 

[Pure_Brew]

I appreciate that. Its a good thing I have decent replacement drivers from Snell in any case. The surrounds I bought didn't look like a good fit either.

 

[mlucitt]

This is a good thread. I had 2 pairs of JBL 125A 10" low frequency drivers re-coned at different times by different outfits. Both technicians claimed they used the JBL C8R127A factory re-cone kits. The first one looks like it was a simple re-foam and went as planned so I had no problems sending in the second pair about 4 years later. This time however, they did not replace the dust cover. They cut a hole in it and then patched the hole when they were done. Also, they did not replace the gasket material on top of the new cone. I was not happy with the appearance, but there was not much I could do about it because sending it back would not change their process. I would get an assurance of their process before I send in any more speakers for re-coning. Fortunately, all four drivers have no VC rubbing and they sound fine.
[attachment=1:qkfiiaup]JBL 10 inch Driver Recone 1.jpg[/attachment:qkfiiaup][attachment=0:qkfiiaup]JBL 10 inch Driver Recone 2.jpg[/attachment:qkfiiaup]

 

[Pure_Brew]

When I refoamed my 10" woofer on the Boston Acoustics A150, I remove the caps and put replacements on. The foams were a really excellent match. The replacement dust caps were porous however, so I sealed them with a coating of adhesive. They still work and sound good.

Personally, I think refoaming a woofer in a 3 way speaker is a bit safer then a woofer in a 2 way as a novice. There would likely be more noticeable changes in the high frequency/mid band.

Imagine doing a pair of 901's....omg!

 

[ksrigg]

Mark, you can always request they be redone. If the same company did the first ones correctly, you had every right to assume they would do the second set the same way....I'd contact someone at the head of the company and send pictures, and then...you can always request a "stop payment" or reversal of charges on your credit card. It can be done. Or it may not be that important to you...I just don't know...I'd probably try to get it fixed and redone before it is too late....If you don't ask, you'll never know...I'll bet they will make it right..
And yeah, I'll bet a pair of 901's would be really great fun. I think the version one and two had cloth surrounds, so if I were to pick up a pair, I'd be looking for one of thoser versions..

 

[Pure_Brew]

I kinda like corrugated/linen surround on some old speakers I've heard. Lasts soooo long.

Off topic, is there a decent 8" driver with corrogated surround that could be used in a 2 way, and still get decent bass in a ported in closure on the large size? Like 2-3cubic feet?