Got myself some "new" speakers, for almost nothing 
I think thay are oldies but goodies, with a enclosure made of concretefiber, and equiped with a ScanSpeak 3/4 inch tweeter, a Vifa M21WO ... woofer and a passive radiator also Vifa M21 ....
They are from back in the late 70'es and was considered as very good speakers of the time.
There is sound in both, but they need at least new surrond for all woofers.
They also need a new coat of paint and new fabric for the grill.
The filter looks really good, with 4 big Rifa foil caps and ok looking coils. Only a single 10uF alu cap will need changing ... might change the terminals as well, but don't really have to.
Now first things first, restoration of the woofers:
Have looked at both Alles over (zelfbouw) Hifi - Audio and Alles om uw luidsprekers te repareren, foamranden, rubber randen, diafragma's enzovoorts. Does anyone have experience with these companies?
Speaker Repair Shop seems to be almost half price .... so tempted to order ned surrounds there.
Next question is rubber of foam?
Originally made with foam, so that will of course work. Rubber will last somewhat longer, but might add a bit of moving mass, and change compliance a bit .... not sure what effect it will have on Rms.
Any experience here?
The membranes looks ok, but I'm considering whether I should give them a thin layer of new coating. If so what coat should I use?
Have some polyester which will give a pretty hard layer. This might change the breakup a bit, and might have to be corrected in the filter.
This will also add a bit og mass.
On the orher hand, the added mass will also give a lover fs, and might give a few Hz at the low end. It will also lower the sensivity a little, which is not a problem as they seem really sensitive as speakers go today ... and today enough amplifier power is not a problem as it was in the 70'es.
Could also add an extra magnet to the active woofers.
Any thoughts??
Looking forward to getting these beauties up to date again
Kind regards Baldin
I think thay are oldies but goodies, with a enclosure made of concretefiber, and equiped with a ScanSpeak 3/4 inch tweeter, a Vifa M21WO ... woofer and a passive radiator also Vifa M21 ....
They are from back in the late 70'es and was considered as very good speakers of the time.
There is sound in both, but they need at least new surrond for all woofers.
They also need a new coat of paint and new fabric for the grill.
The filter looks really good, with 4 big Rifa foil caps and ok looking coils. Only a single 10uF alu cap will need changing ... might change the terminals as well, but don't really have to.
Now first things first, restoration of the woofers:
Have looked at both Alles over (zelfbouw) Hifi - Audio and Alles om uw luidsprekers te repareren, foamranden, rubber randen, diafragma's enzovoorts. Does anyone have experience with these companies?
Speaker Repair Shop seems to be almost half price .... so tempted to order ned surrounds there.
Next question is rubber of foam?
Originally made with foam, so that will of course work. Rubber will last somewhat longer, but might add a bit of moving mass, and change compliance a bit .... not sure what effect it will have on Rms.
Any experience here?
The membranes looks ok, but I'm considering whether I should give them a thin layer of new coating. If so what coat should I use?
Have some polyester which will give a pretty hard layer. This might change the breakup a bit, and might have to be corrected in the filter.
This will also add a bit og mass.
On the orher hand, the added mass will also give a lover fs, and might give a few Hz at the low end. It will also lower the sensivity a little, which is not a problem as they seem really sensitive as speakers go today ... and today enough amplifier power is not a problem as it was in the 70'es.
Could also add an extra magnet to the active woofers.
Any thoughts??
Looking forward to getting these beauties up to date again
Kind regards Baldin
