As advised, I've started a thread here in the workbench section...

As it stands, I have 4x CX100 drivers and a set of Visaton tweeters. What I plan to do is cook up a set of speakers based on the CX100s, but with differences made to the crossovers/enclosure design. If anyone has the Thiele-Small parameters of the drivers used in the CX100s I'd be very grateful if you could furnish me with them.

Failing that, I'll get them from B&O themselves. Now...to find replacement foam suspension!

 

L

the best bet for replacement foam, is not to use foam at all, but rubber surrounds

A pair of 9.8cm high quality rubber speaker surrounds for about 10 quid is what you really need to replace the deteriorated foam surround so that your woofers will work well for another 20 years.

The surrounds from Good HiFi are the best fit, and also work on these other B&O woofers found in other speakers from the B&O range, they all use the same Foster 10cm speakers from Japan

    * B&O Beovox C30 woofer
    * B&O Beovox C40 woofer
    * B&O Beovox C75 woofer
    * B&O Beovox CX50 woofer
    * B&O Beovox CX100 woofer
    * B&O Beovox M75 mid-toner
    * B&O Beovox M100 mid-toner

http://www.goodhifi.com  email :  good_hifi@zonnet.nl  

GoodHiFi are an excellent B&O accessories supplier in Holland, his name is Maroesjka

His website explains it all   http://www.goodhifi.com/Checks/checks.htm

 

best of luck

Peter

 

those were the ones I ordered, pete. Funny, I was chatting in Afrikaans to him, and he understood perfectly! They've just arrived at home, will start tonight. Despite looking, it appears Foster have discontinued them. At least I got the brand right! Going to measure the parameters.

THIS thread offers some good tips on getting it right.

 

Chris.

Cheers, I actually intend to shim the voice coil, to make double double sure!

 

Stand by for photoooos

what were the Thiele-Small measurements ?

Hey,just finished the first stage of gluing, will set the outsides today and let you know when they're done :D

UPDATE

The basket side is now setting, and 0-20Hz sweeps have reported no rubbing!!

Used the battery method with a 6v SLA

L

T/S of part # 8480173

http://liammartin.com/twaddle/woofer.jpg

Here be a guide for refoaming CX100s!

 

http://blog.liammartin.com/node/9

Liam, your 4 drivers you measured have a VAS value of   1.71 litres

 

but the two woofers on the Foster website measure respectively:

model  number   434126 is 2.2L

model  number   434127 is 3.2L

Overture,

 

I believe they aren't the same driver as the ones in the CX100s. Very similar, but not identical

how have you progressed with this project Liam  ???

Admittedly, it has been slightly sidelined. I'm sitting my Finals this week (computer & electronic engineering... :S) so, I'll get going afterwards :)

Righteo - moved to Montréal at the end of last year. Currently in Ireland on contract but heading back early March, with the drivers and some Visaton tweeters in my checked baggage. 

The logic behind this is brewing up some cabinets while I'm finding work (and a tiny wee Class-A MOSFET-based amp) until my valve stuff arrives on the boat. Debating whether I should throw my Mission 701s onto the pallet too...just in case the CX100-frankenstein project goes awry (sounds crap) and I'm left with no decent speakers!

L

I'm in Montreal. I have refurbished plenty of CX's . 
The rubber surrounds from Good hifi are excellent and the only ones I recommend. Though they need some 'play-in' time to soften up somewhat. 

I think I have some original crossovers left if you are interested. However I recommend proper replacement ones. 

Good luck on your project!

Hey! 

What part? St-Dominique here. Yeah, I can see going for a 'proper' crossover :  what's actually in there? Single-stage RC affair?

 

L

Hey! 

What part? St-Dominique on Plateau here. Yeah, I can see going for a 'proper' crossover :  what's actually in there? Single-stage RC affair?

 

L

The existing crossover is not really anything to write home about.

2 coils, one of which is the same as in the cx50.
1 cap (have to check) but should be a bipolar 6,8/63v

If you want something better and 'off the shelf' try something like :
http://cgi.ebay.com/Boston-Acoustics-Dual-Woofer-2-Way-CrossOver_W0QQitemZ360229641705QQcmdZViewItemQQptZSpeakers_Subwoofers?hash=item53df5c1de9 

There are plenty of alternatives out there and even cheaper ones. As long as it is a dual woofer type.
I did use the above one as-is with fairly good results with improved overall performance with richer mid tones and a bit more bass.

If you need more info, you can contact me by email.