General Forum

Re: Refoaming Beovox M75

riis — Fri, 11 Apr 2008 09:12:35 GMT

Another pic.

Re: Refoaming Beovox M75

riis — Fri, 11 Apr 2008 09:09:33 GMT

My restoring project is completed. The woofer and the filler have been refoamed, never tried it before but it was a rather straight forward job.

The hardest part was to sandpaper and polish the cabinets, but I'm rather pleased with the result.

And the sound is awsome...............

Re: Refoaming Beovox M75

Peter — Thu, 06 Mar 2008 14:05:01 GMT

Minimal difference - I had the surrounds on my MS150s replaced with rubber and then had them tested - frequency response as flat as a pancake!

Re: Refoaming Beovox M75

riis — Thu, 06 Mar 2008 13:21:05 GMT

I saw at Good Hifi's website that I can get rubber surrounds and now I can't help thinking, "Why don't I order rubber surrounds instead of foam surrounds" I have the idea that the rubber surrounds will last much longer, but what difference will they make sound wise compared with the foam surrounds?

Re: Refoaming Beovox M75

riis — Wed, 05 Mar 2008 10:59:12 GMT

Here is what I have done to the cabinets. Even though they looked terrible they didn't have any deep scratches or torn off veneer. I think the damage is mostly discoloration due to water from pot plants and vases. I don't know why the rosewood has grown light so much that it almost looks like teak.

I cleaned the cabinets with wood cleaner, the stuff you use on not painted wood before you paint or oil it.
I cleaned the cabinets with clean water.
When the cabinets were dry, I started sandpapering and polishing with waterproof sandpaper # 600 and teak oil.
You'll have to repeat step 3 several times as the sandpaper very quickly fills with a mixture of oil and dust. I think I repeated the process 4 times. You have to be careful not to go through the veneer. The veneer on the M75 seem to be of a very high quality, so you can do a lot of sanding without "going through"
When you can't see any discoloration you stop sandpapering and you polish the cabinet with a dry piece of cloth.
You oil the cabinets once or twice depending of how much they absorb.

Be careful with the cloth you have used for oiling. Burn them or you risk self-ignition!!!

riis/

Re: Refoaming Beovox M75

Peter — Wed, 05 Mar 2008 09:07:09 GMT

I had my M100.2s done by Recone and they couldn't get the correct surround for the phase link unit. They too did a cut and shut and it seems to work very well.

I second the thoughts above - beautiful job on the cabinets. Well worth it too! While you are there, replace the capacitors - there are a lot! Made a huge difference to mine.

Re: Refoaming Beovox M75

Ben — Wed, 05 Mar 2008 09:00:35 GMT

I modified the surround by slicing a section out of it, and glueing it back together, creating the correct diameter. This was about 10 years ago, and not many different sizes of surround were easily available back then. Maybe you can find one that fits perfectly these days.

I shimmed the woofer and 'phase link' units, but if i was doing it again, I probably wouldnt bother shimming the smaller driver. I've refoamed several small speakers since without shims with no problems. The smaller drivers with a light cone seem to self centre quite well.

I still shim large drivers though, they have a tendancy for the cone to rock when there is no surround to support them.

Maybe the size of the phase link units are measured differently because of the shape of their chassis'. I remember the surround was just slightly over 4"

Ben

Re: Refoaming Beovox M75

riis — Wed, 05 Mar 2008 07:19:54 GMT

h1npw:

Bit of an understatement jgunzelman!!!!!!! Absolutely amazing - I would never have thought it was possible.
riis - Is it possible to give us a step by step description on how you did it and what materials you used ?
Cheers
Nigel

Thanks Nigel. Of course I'll give a step by step description. Isn't it what this forum is about? To share our knowledge I'm a bit busy right now but I hope to be able to post a description later today

riis/

Re: Refoaming Beovox M75

h1npw — Wed, 05 Mar 2008 05:22:45 GMT

Bit of an understatement jgunzelman!!!!!!! Absolutely amazing - I would never have thought it was possible.

riis - Is it possible to give us a step by step description on how you did it and what materials you used ?

Cheers

Nigel

Re: Refoaming Beovox M75

jgunzelman — Tue, 04 Mar 2008 18:45:51 GMT

Nice job on the finish! What did you use?

Re: Refoaming Beovox M75

Alex — Tue, 04 Mar 2008 16:45:39 GMT

Can't really say I know much at all about these speakers, but the midrange units look very similar to the classic PMC design (copied by ATC), often considered to be one of the best midrange units designed (they cost in the order of £300+ now I believe).

Re: Refoaming Beovox M75

Dillen — Tue, 04 Mar 2008 14:31:39 GMT

The tweeter and midrange drivers are both dome's. The filler and woofer are cones. The same filler is used in Beovox M100 and M100-2.

Martin

Re: Refoaming Beovox M75

magnushj — Tue, 04 Mar 2008 13:48:06 GMT

www.goodhifi.com is also a good source of foam surrounds. I have used them a couple of times. The website looks a bit dodgy, but they are very helpful with finding the correct size for your unit and they ship fast.

Re: Refoaming Beovox M75

riis — Tue, 04 Mar 2008 11:40:39 GMT

ben12345:

I think there must either be a discrepancy in the specification, or there were different versions of the M75 with a 12.5cm unit.
Mine also measure smaller. I refoamed mine with a 4.5" foam surround modified to fit. I cant remember where I got the surrounds for the M75, but i've used www.speakerbits.com and www.newfoam.com in the past on other speakers with good results.
Your cabinets look great BTW!

What did you have to do with the 4.5" to make it fit? How did you solve the problem with centering the cone? Did you use shims?

Re: Refoaming Beovox M75

Ben — Tue, 04 Mar 2008 10:35:19 GMT

I think there must either be a discrepancy in the specification, or there were different versions of the M75 with a 12.5cm unit.

Mine also measure smaller. I refoamed mine with a 4.5" foam surround modified to fit. I cant remember where I got the surrounds for the M75, but i've used www.speakerbits.com and www.newfoam.com in the past on other speakers with good results.

Your cabinets look great BTW!