The Workbench

Re: Refoaming Beovox S80

Søren Mexico — Thu, 23 Feb 2012 19:03:36 GMT

Do like this, I gave the instructions to Rudy, (Harry Pierce) and his 3702 8" drivers are playing okay even with the bend in the voice coil, Shim, shim, shim

Re: Refoaming Beovox S80

Eugene — Thu, 23 Feb 2012 11:22:53 GMT

Leslie:

Bad surround? Or the dustcap?

incorrect installation on the inner surround ring pushing the driver forward slightly here is how it looks after I reworked it using Good Hifi rings.

Re: Refoaming Beovox S80

Leslie — Thu, 23 Feb 2012 11:02:03 GMT

Bad surround? Or the dustcap?

Re: Refoaming Beovox S80

Eugene — Thu, 23 Feb 2012 10:37:36 GMT

Leslie:

Completely out of center? Is that what I see Eugene?

You are about half right Leslie

Take a look at your surround installation then a closer look at mine. You will eventually spot the difference.

Re: Refoaming Beovox S80

Leslie — Thu, 23 Feb 2012 10:18:51 GMT

Completely out of center? Is that what I see Eugene?

Re: Refoaming Beovox S80

Eugene — Thu, 23 Feb 2012 10:16:28 GMT

Here is my contribution regarding faulty repairs - an S80.2 driver professionally refoamed incorrectly. I wrote up a thread on this about a year ago.

Re: Refoaming Beovox S80

Leslie — Thu, 23 Feb 2012 10:10:02 GMT

Dillen:
Someone who has done hundreds before. Someone who don't need your woofers to be the
first ones to practice on.

Next time when I have to visit Denmark I will drop by, thanks Martin

Re: Refoaming Beovox S80

Leslie — Thu, 23 Feb 2012 10:02:58 GMT

Rich:

Leslie:

Rich:

Leslie, if you want a DVD of the whole process, PM me your mailing address and I'll send you one.

That's a nice offer Rich, would you do that for me?

Of course.

Thanks Rich, much appreciated! What a great and helpfull place this is!

Re: Refoaming Beovox S80

Dillen — Thu, 23 Feb 2012 10:02:27 GMT

Leslie:

Martin, I've seen your pictures an they look worse! What do you think these kind of people would handle when using the shimming method. They should keep their hands off refoaming at all!

Yes.
As said, not all people are cut out for DIY. Some are definitely NOT.
Only last week, an owner told me "The screwdriver slipped when I took the woofer out...".
*sigh*.
What may seem a piece of cake to you may be quite a task for someone else, maybe downright impossible.
CX50/100 are not too tight but I can assure you, it CAN go wrong if you don't shim them.
If the drivers played (or just stood) for a long time with bad surrounds, the weight of
the cone etc. will deform the spider (and sometimes even the cone itself). Not a lot, not even visible
but enough to cause the coil former to start rubbing a couple of weeks after being refoam'ed when things
are slowly settling again.
In severe cases, that can happen even if you shim'ed it. Therefore I often mark the drivers
with up and down and often ask the owners to do so too before sending drivers to me.

And why not shim ?
It's not particularly time consuming (this is hobby for us, right ?), it's not particularly difficult and
it's not even expensive and it does give you a better chance of success.

The general advice, I think, should be:

- If you feel, you are very good with DIY jobs and have a good "mechanical feeling and touch", you
may be able to refoam speaker drivers yourself. Aligning the coil is what the factory did and it's
highly adviceable to do the same.
However, if you, while you work, suddenly feel that you are in too deep or face an unexpected issue - STOP!

- If you don't feel 100% up to the task, leave it someone who is, right from the beginning.
Prof refoam'ers are worth their cost and those unique B&O woofers are not too plentyful.
If you have to redo a refoam job for some reason, you will already have lost the amount of money a pro refoam costs.

Personally, and as a Beoworld Technical Advisor, my advice is to let someone do it for you.
Someone who has done hundreds before. Someone who don't need your woofers to be the
first ones to practice on.

Martin

Re: Refoaming Beovox S80

stevepe — Thu, 23 Feb 2012 10:02:03 GMT

It's after the battery method at the bottom of the first page. It's my entry.

Re: Refoaming Beovox S80

Leslie — Thu, 23 Feb 2012 09:58:28 GMT

Just had a quick view Steve and I already saw this thread but I can't see any shimming. Just the battery method, or is that shimming? Now I'm really confused

Re: Refoaming Beovox S80

stevepe — Thu, 23 Feb 2012 09:55:00 GMT

Leslie:

Rich:

Leslie, if you want a DVD of the whole process, PM me your mailing address and I'll send you one.

That's a nice offer Rich, would you do that for me?

Leslie,

There a some photos of the small drivers being shimmed on this thread after the battery method is illustrated: http://forum.beoworld.org/forums/t/36917.aspx

My first re-foam was a set of C75's and I discovered a slight rubbing sound on one driver a few weeks later. I re-did it with shims, and wished I would have done them all that way to begin with. The stiff little dust caps are pretty easy to cut and fold back and re-glue in the same place. I use the stuff called tacky glue.

Steve

Re: Refoaming Beovox S80

Søren Mexico — Thu, 23 Feb 2012 09:50:30 GMT

Leslie:

Finally Martin, you're back!

I'm convinced, because of all these good advises that shimming is a need to do refoaming the right and precise way. However, and I have not done this shimming method before, I wonder if this is really necessary for small diameters like CX50/100 drivers? Other thing is, would people with no experience at all take risks by damaging the cones/spider. I mean, you have to cut out the dust cap (if I have understand this correctly, you have to make sure no dust will come inside the center cone etc. Would be great if someone could make a sort of photo session while doing this refomanig/shimming process!

I'm onto it in the new forum, there will be a full wiki, will finish this weekend,

Re: Refoaming Beovox S80

Rich — Thu, 23 Feb 2012 09:48:05 GMT

Leslie:

Rich:

Leslie, if you want a DVD of the whole process, PM me your mailing address and I'll send you one.

That's a nice offer Rich, would you do that for me?

Of course.

Re: Refoaming Beovox S80

Leslie — Thu, 23 Feb 2012 09:41:46 GMT

Rich:

Leslie, if you want a DVD of the whole process, PM me your mailing address and I'll send you one.

That's a nice offer Rich, would you do that for me?