Hi everyone,
I attach a few photos of these beautiful drivers: here serving the midrange in some recently acquired CELEF Studio Professional Transducers. I have found a couple of other threads relating to repair of these drivers (and also in connection to these same CELEF models) here and on AudioKarma where owners have problems with the early-model surrounds shrinking. Thankfully, mine have the later PVC surrounds which still seem to be going strong. However, you will see in the photos that the very outer surround ring is coming away in a few places from the PVC surround. There is not a great deal of driver movement at this outer edge and therefore I assume I can glue them back down? The surround seems to be made of paper/card.
Can anyone recommend an appropriate glue? I assume something such as the glues available here be suitable?
My other question is about the little nodule of PVC in the first image -- I wonder if this has actually unseated the glue? would it be foolish to try and remove this before sticking down the surround? Maybe it would be better to just attempt to cut out a tiny notch in the outer card surround to fit around it? I don't see the same thing on the other driver (there is a little one but it's not impacting the surround). Are these caused by the mold during production of the surround? it will make sticking the surround back seamlessly impossible.
I am also interested to hear from any fellow, knowledgeable CELEF owners. Unlike the other examples of these drivers discussed these do not have Stuart Tyler's 'modifications' -- which seems to amount in other examples to AT LEAST the addition of cork to the spider (?) and a CELEF sticker covering the back of the magnet. Mine have no such cork and no such sticker... the Audax name and model number is clear. I don't know if they dropped these 'mods' in the later production of these speakers -- although I don't believe that many sets were ever produced. Anyway, would be interested to compare notes on this with any eager parties 😉
Anyway, thanks in advance for any input anyone might have!
I have only had time to listen to these speakers briefly, but they sound absolutely stunning...and that was a quick test of each alone....who knows what the stereo pair might achieve!
Nick
I attach a few photos of these beautiful drivers: here serving the midrange in some recently acquired CELEF Studio Professional Transducers. I have found a couple of other threads relating to repair of these drivers (and also in connection to these same CELEF models) here and on AudioKarma where owners have problems with the early-model surrounds shrinking. Thankfully, mine have the later PVC surrounds which still seem to be going strong. However, you will see in the photos that the very outer surround ring is coming away in a few places from the PVC surround. There is not a great deal of driver movement at this outer edge and therefore I assume I can glue them back down? The surround seems to be made of paper/card.
Can anyone recommend an appropriate glue? I assume something such as the glues available here be suitable?
My other question is about the little nodule of PVC in the first image -- I wonder if this has actually unseated the glue? would it be foolish to try and remove this before sticking down the surround? Maybe it would be better to just attempt to cut out a tiny notch in the outer card surround to fit around it? I don't see the same thing on the other driver (there is a little one but it's not impacting the surround). Are these caused by the mold during production of the surround? it will make sticking the surround back seamlessly impossible.
I am also interested to hear from any fellow, knowledgeable CELEF owners. Unlike the other examples of these drivers discussed these do not have Stuart Tyler's 'modifications' -- which seems to amount in other examples to AT LEAST the addition of cork to the spider (?) and a CELEF sticker covering the back of the magnet. Mine have no such cork and no such sticker... the Audax name and model number is clear. I don't know if they dropped these 'mods' in the later production of these speakers -- although I don't believe that many sets were ever produced. Anyway, would be interested to compare notes on this with any eager parties 😉
Anyway, thanks in advance for any input anyone might have!
I have only had time to listen to these speakers briefly, but they sound absolutely stunning...and that was a quick test of each alone....who knows what the stereo pair might achieve!
Nick
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Hi Nick,
these chassis are relatively rare, so there might not so much experience out there. I have speakers with relatively similar ones. The speakers have been built by a small dutch speaker manufacture in the 1990s. I assume mine are Audax, too. 6.5". They also have the cardboard rings over the surrounds. They also have come loose.
I lent them to my kids and some friends to party a couple of times... had not other speakers to use for this at those times. They kept sounding clean even played very loud, but obviously suffered.
I bought some white glue (like the one you use with wood) on recommendation but have not dared to start the repair. I would just glue the surrounds back.
Speakers sound very nice. They are bass reflex and have two extra woofers, each one behind each Audax mid woofer in the cabinet. Plus what seems to be a large tweeter and a super tweeter. Or a small mid and a tweeter? Did not trace out the schematics of the crossover yet.
these chassis are relatively rare, so there might not so much experience out there. I have speakers with relatively similar ones. The speakers have been built by a small dutch speaker manufacture in the 1990s. I assume mine are Audax, too. 6.5". They also have the cardboard rings over the surrounds. They also have come loose.
I lent them to my kids and some friends to party a couple of times... had not other speakers to use for this at those times. They kept sounding clean even played very loud, but obviously suffered.
I bought some white glue (like the one you use with wood) on recommendation but have not dared to start the repair. I would just glue the surrounds back.
Speakers sound very nice. They are bass reflex and have two extra woofers, each one behind each Audax mid woofer in the cabinet. Plus what seems to be a large tweeter and a super tweeter. Or a small mid and a tweeter? Did not trace out the schematics of the crossover yet.
To me, yours look like Audax HD 20 B drivers. More vintage Audax drivers are here: http://www.audax.com/archives.php
And the 1990 catalogue is here: http://www.retronik.fr/Audiovideo/AUDAX/AUDAX_Realisez_vos_kits_et_vos_ensemble_Notice_90-6.pdf (in French).
Mine might be:
Audax MHD 17 B 25 drivers.
More input from other sides welcome!
Sold a lot of those 8” Audax in the late ‘70s, the Tangents used them (one of my favourites).
I have a pr of Divas with the 6.5, they come with a spare bass driver.
dave
I have a pr of Divas with the 6.5, they come with a spare bass driver.
dave
Those 4” are vintage Coral Holey basket AlNiCos, given 2/side I’d guess 16 ohm ones poached out of the little Monarchs.
And I’d guess a whalfdale tweeter (Galu?)
dave
Thank you, @planet10. "Coral Holey basket AlNiCos", holy cow. It seems I have fished something interesting there. There is only one per side though.
Bought the speakers for cheap 10 years ago and used them for about 2 years. They have kitchen tiles inside for stiffness. Can't carry one alone.
The surrounds in mine seem to be different,. Is this possible? There seem to be different surrounds around for those. They are very stiff and small. I can't imagine how folks are using them in full range designs.
The tweeter is a very generic cheap mass market design I think. Used as a supertweeter I now guess. I am curious to redraw the crossover schematics now and understand the crossover frequencies of the Coral (if it is one). The mid woofers, as I said, are double, and both in isobaric configuration. They can do very good low frequencies (if they are intact, that is 🙂
Bought the speakers for cheap 10 years ago and used them for about 2 years. They have kitchen tiles inside for stiffness. Can't carry one alone.
The surrounds in mine seem to be different,. Is this possible? There seem to be different surrounds around for those. They are very stiff and small. I can't imagine how folks are using them in full range designs.
The tweeter is a very generic cheap mass market design I think. Used as a supertweeter I now guess. I am curious to redraw the crossover schematics now and understand the crossover frequencies of the Coral (if it is one). The mid woofers, as I said, are double, and both in isobaric configuration. They can do very good low frequencies (if they are intact, that is 🙂
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I loved and owned many pair of Tangents! RS4, RS6, and I even had a pair of rosewood RS8s (got them as they were shutting down, one of the last pairs they delivered).
I sad RS2, 4, & 8(cherry). My buddy had 6s
I learned a lot from John Greenbank
And we had an interesting happening one Friday evening. Always a inch of customers chatting & such.
John was over from the UK, RS4s driven by a 4B. Loud!
All of a sudden acrid white smoke started coming out the square vent, and the woofer stopped. Dan & I sprang to action swapping the woofer and 15 min later we were back in action. Besides the woofer we tad lilt the foam damping on fire from a hot resistor
dave
I learned a lot from John Greenbank
And we had an interesting happening one Friday evening. Always a inch of customers chatting & such.
John was over from the UK, RS4s driven by a 4B. Loud!
All of a sudden acrid white smoke started coming out the square vent, and the woofer stopped. Dan & I sprang to action swapping the woofer and 15 min later we were back in action. Besides the woofer we tad lilt the foam damping on fire from a hot resistor
dave
I have glued down loose perimeters before - often on subwoofer passive radiators. Just make sure you're nicely aligned and glue it down. You should be good to go.
Thanks all for your helpful input: I agree it looks like it should be fine just to glue them back down. That said, half the ring sits on top of the edge of the PVC surround where it terminates on the frame; the other half looks to stick down on the frame itself. So I need a glue which will handle the sticking to the PVC. I think the reason they are coming unstuck is that the original glue is not holding on the PVC -- seems ok on the frame. It looks to me like the glue linked in my OP should work fine (it's acrylic based) -- i don't think the white glue approach will work as i believe this won't bond with PVC?
Second question here: do these surrounds have any sonic importance? Or are they purely aesthetic (hiding glued edge of surround)? As far as i can tell they attach on top of the very edge of the surround which is itself flat and glued to the frame so not subject to any movement during driver operation. Thus i can't see how they can have any sonic value unless there's some subtle wave guidance provided by them?
Having looked at the rear of the magnet i can confirm the model number is definitely the HD20 B 25 H. Although i believe there was more than one version of this -- not sure which of the two it is.
Second question here: do these surrounds have any sonic importance? Or are they purely aesthetic (hiding glued edge of surround)? As far as i can tell they attach on top of the very edge of the surround which is itself flat and glued to the frame so not subject to any movement during driver operation. Thus i can't see how they can have any sonic value unless there's some subtle wave guidance provided by them?
Having looked at the rear of the magnet i can confirm the model number is definitely the HD20 B 25 H. Although i believe there was more than one version of this -- not sure which of the two it is.