ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
To answer Nick's earlier question, this is my next project, a refoam and crossover recap on a tidy pair of Beovox S120.
This is obviously a high quality woofer (8 ohm) with a cast aluminium basket, a whopping great magnet and some weight to it. Can anyone tell me who made it?
Peerless, I believe.
Martin
There must be any number of enthusiasts who refoam speakers to a high standard, but I thought I'd share my method (might be useful to somebody) as the S120 woofer is slightly harder to repair than its lesser brethren on account of the size of the voice coil and consequent steep angle of the cone. This makes concentricity slightly harder to achieve.
I use pins (with the blue flag) stuck through the foam to enable alignment of the edge of the cone with the new surround. Small neodymium magnets (wrapped in insulating tape) then clamp the two together for initial glueing.
I will use shims to centre the cone on the pole piece.
The foam vent on the reverse of the voice coil is disintegrating. Would any open structure foam do as a replacement?
(Martin, thanks).
The foam in the centre of the pole piece underneath the dustcap is pretty fragile after nearly forty years. I gave some thought to replacing it with some similar open cell foam, but decided against. Not sure what it does.
I used three 0.1mm shims cut from acetate sheet to centre the cone. However, on both speakers, the cone is not exactly concentric with the basket which involved slightly offsetting the new surround.
And the dustcap back in place.
Well done - the old curator of the B&O Time tunnel reckoned these were possibly the best passive speaker made by B&O.
Peter
I have a pair, expertly re-foamed by a Beoworld member 😉
They are extremely neutral speakers that need space to give their best. They image very well with great depth. They are a little bass shy if not against a solid wall. The box is made of plywood.
I use mine with a Beomaster 8000 receiver.
Jacques
Gents, thank you for your input. Neutral is what I like.
I have recapped the crossovers. Reichelt Elektronik is a good source for these TREC branded bipolar audio caps at around €1 each but it remains to be seen (heard) whether I end up reinstalling the old Roederstein 'golden bullets' which are still perfectly within spec. Recapping crossovers is one of those articles of faith that deserves to be challenged.
Now onto the rosewood cabinets. A bit of sawdust and superglue makes a good filler for those vulnerable corners.
The S120 is a bass reflex speaker and the reflex port is at the bottom of the cabinet shown here.
I thought conventional wisdom has it that the enclosure shouldn't contain too much sound deadening or the reflex function will fail to work.
Also, peculiarly, the gasket sealing the resin loudspeaker plate to the cabinet only extends a short way down the sides of the enclosure.
After four applications of Danish Oil with the final one applied with an ultra fine abrasive pad, I have a satin finish that shows the veneer matched cabinets well.
The sound of these is utterly different to my more coloured S55 Beovox. The S120s are transparent, accurate and more present for a given volume setting. Bass is certainly not absent. I notice a very slight tendency to shrillness. Recorded piano sound is always a good test, and these pass. The spoken voice is another good test, and I'm not entirely convinced by these - though I have yet to hear any loudspeaker that enables speech to sound like it's not coming out of a box.
Krolroger:The spoken voice is another good test, and I'm not entirely convinced by these - though I have yet to hear any loudspeaker that enables speech to sound like it's not coming out of a box.
Krolroger: After four applications of Danish Oil with the final one applied with an ultra fine abrasive pad, I have a satin finish that shows the veneer matched cabinets well. {}
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They look fantastic. Like new!