General Forum

Re: refoaming cx 50s.....

wirralsimon — Thu, 19 Aug 2010 07:04:24 GMT

Xseries:

We all do this slightly differnetly I guess! I prefer to take the drivers out of the speaker to get better access and not let bits of foam drop into the baffle material or the speakers casing. Ihave found using 20+ clothes pegs (ie all round) helps if you cannot find a glass of the right diameter.

I also prefer not to risk scratching the aluminium casing (though of course that may not apply to old second (third, foruth or fifth) hand speakers. It always saddens me when I see the condition some people allow their B&O kit to become.

Brian

That's my approach!

I tried (and failed) to refoam a pair of CX50's with the drivers in and it was a complete failure. When you have pegs all round you can test by pushing the driver in that there is nothing rubbing and quickly and easily adjust. When the drivers are still in the speakers and you are using cups there is much more of an element of hoping you have got it right, and in my case I had got it wrong and ended up buying new drivers.

It is completely straightforward removing and replacing the drivers and makes everything so much easier! I had no trouble refoaming two pairs of CX100s the next time round with the drivers out and really cannot understand why anyone would make it so much more difficult for themselves by leaving them in while doing the work.

Simon

Re: refoaming cx 50s.....

AdamS — Thu, 19 Aug 2010 04:34:32 GMT

As a final though on the re-foaming subject, I buy my foams from NewFoam in the USA in the form of a kit that inclides, foams, glue, shims and replacement dust caps.

I personally find it far safer to cut the old dustcap off and use shims down inside the voice coil to hold everything solid and equally spaced whilst doing the re-foam job.

Talking of which, as I now have CX100s, CX50s, Beovox M150s AND a pair of Videoton Musical Encyclopedias to re-foam, I suppose I should get the ruler and the credit card out......

Re: refoaming cx 50s.....

js — Wed, 18 Aug 2010 04:48:30 GMT

All right, thank you for the advice, I will de-solder the drivers.

But then how do I connect the 1.5V battery? Thanks.

Re: refoaming cx 50s.....

wirralsimon — Wed, 18 Aug 2010 04:38:13 GMT

The first time I tried refoaming I followed a tip from another posting on here that suggested you could refoam without completely removing the drivers.

It was an unmitigated disaster and I ended up buying new drivers!

A soldering Iron and solder will cost a nominal sum on ebay and removing the drivers completely makes everything 100% easier. I have since successfully refoamed two pairs of CX100's without incident, the soldering skills you need really are minimal.

If this is your debut refoam it really isn't worth trying to save a few euros by not buying a soldering iron!

Simon

Re: refoaming cx 50s.....

tournedos — Wed, 18 Aug 2010 03:01:45 GMT

The crossover keeps DC out of the tweeter, so there's no danger.

But... as far as I remember, the internal wiring has just enough slack for the (de)soldering job, and you'll have a very hard time doing the reconing without being able to even lay the driver flat on the table! The wiring might rip off anyway...

Re: refoaming cx 50s.....

js — Wed, 18 Aug 2010 02:47:01 GMT

Craig:

I connect a 1.5 volt battery to the speaker. This pulls the cone in squarly. Then I peg it in place and disconnect the battery. 9 times out of 10 it is in the corect place and no scraping can be heard if I bress the cone in.

Medogsfat:

Looks like we all do the same thing.

I also use a 1.5 V battery to centre the speaker before allowing the outer of the rings to set. [...] You can test for correct centering by feeling for any rubbing by simply pressing the centre of the dust cap in a straight line inwards.

Chris.

Craig, Chris,

Thank you for sharing, that is mucj appreciated.

Just one question: can I connect the 1.5V AA battery directly to the SpeakerLink cable i.e. + to the round pin and - to the flat pin? Is there any risk for the tweeter or the cross-over?

The reason I am asking is that I don't have a soldering iron so I don't want to disconnect the drivers and not be able to reconnect after. Therefore I will just unscrew the drivers to have better access for the pegs but I will keep these wired.

Just hope it is not beyond my capabilities

Thanks and regards, js

Re: refoaming cx 50s.....

Craig — Mon, 06 Apr 2009 14:08:34 GMT

Graf:

Thank you for the quick response. I hope this question is not too dense, but how to hook up the battery? Can I leave the driver in place and hook up a 1.5 volt battery (I assume this is the same as a AA battery) to the ends of the speaker wires or can this only be done if the driver is removed. Thanks again!

I always remove the Drivers to refoam them, make it a lot easier.

Craig

Re: refoaming cx 50s.....

Graf — Mon, 06 Apr 2009 13:50:48 GMT

Thank you for the quick response. I hope this question is not too dense, but how to hook up the battery? Can I leave the driver in place and hook up a 1.5 volt battery (I assume this is the same as a AA battery) to the ends of the speaker wires or can this only be done if the driver is removed. Thanks again!

Re: refoaming cx 50s.....

wirralsimon — Mon, 06 Apr 2009 05:13:46 GMT

Thanks Henri

Do the C and CX speakers have differtent size drivers, or can you put a CX driver in a C?

Regards

Simon

Re: refoaming cx 50s.....

Henri — Mon, 06 Apr 2009 03:42:06 GMT

wirralsimon:
If you are technically competent and are restoring a tatty pair to good-ish condition for sale on ebay then the price difference between refoaming and new drivers is probably the profit margin.

Most likely, yes.

However, the sound quality issue is always there. I have a bunch of C/CX series speakers and, 100% subjectively, I prefer the sound of new drivers (+ 30...50 hours of running them in) to reconed ones. The most notable difference is slightly deeper and tighter bass, which may be caused by the evolution of driver manufacturing from mid 80's to early 00's. Still, the speaker of choice of these all are C75 for me, imaging is very good and there's an overall feeling of smoothness in the sound. I had to buy yet another pair of CX100:s, only because C:s are just a bit too good to be used as "just" surround speakers. The sad thing is that once foam rot sets in, new drivers aren't available anymore so refoaming is the only option.

All in all, both C and CX are fantastic small speakers. I've even retired a pair of Dynaudio Audience 42:s in favour of them, and 42:s are among my all-time favourite bookshelf/stand speakers. Design may have something to do with it, too, but sound quality always comes first.

Re: refoaming cx 50s.....

wirralsimon — Mon, 06 Apr 2009 02:10:45 GMT

joeyboygolf:

wirralsimon:

They are still 25.00 each, and soldering the new ones in is lots easier than refoaming the old ones!

Simon

And 30 mins max and job done! None of this cups and weights and clothes pegs and leaving overnight, and messy glue and rotten foam black sh*t cobblers. Another thing I've looked at is the price that Good Hi fi charge and then plus shipping. Is it worth it?

You might as well buy new ones and 30 mins job done!

I can see both sides to be honest. If you are restoring an otherwise mint pair for sale or if you are in any way technically bewildered (i.e. like me!) then I would say buy new drivers.

If you are technically competent and are restoring a tatty pair to good-ish condition for sale on ebay then the price difference between refoaming and new drivers is probably the profit margin.

Simon

Re: refoaming cx 50s.....

joeyboygolf — Sun, 05 Apr 2009 17:45:27 GMT

wirralsimon:

They are still 25.00 each, and soldering the new ones in is lots easier than refoaming the old ones!

Simon

And 30 mins max and job done! None of this cups and weights and clothes pegs and leaving overnight, and messy glue and rotten foam black sh*t cobblers. Another thing I've looked at is the price that Good Hi fi charge and then plus shipping. Is it worth it?

You might as well buy new ones and 30 mins job done!

Re: refoaming cx 50s.....

wirralsimon — Sun, 05 Apr 2009 17:04:56 GMT

They are still 25.00 each, and soldering the new ones in is lots easier than refoaming the old ones!

Simon

Re: refoaming cx 50s.....

Craig — Sun, 05 Apr 2009 16:19:32 GMT

wirralsimon:

Trying to refoam my CX50's was a learning experience for me.

I learned that I lack the skills and dexterity to refoam speakers!

I can however confirm that the original drivers are still available through B&O dealers, and that a quick call to King Street and a trip to Manchester solved the problem!

Simon

Last time I checked they were about £25.00 each.

Craig

Re: refoaming cx 50s.....

wirralsimon — Sun, 05 Apr 2009 16:13:58 GMT

Trying to refoam my CX50's was a learning experience for me.

I learned that I lack the skills and dexterity to refoam speakers!

I can however confirm that the original drivers are still available through B&O dealers, and that a quick call to King Street and a trip to Manchester solved the problem!

Simon