I have a pair of Bextrene cone laminated 8 inch bass driver taken from a pair of B&W DM2.
This is a replacement driver stamped May 1993 and not the original DW200/2 bass driver designed by B&W the 70's. Limited play in the cone can be observed as the coil tube hits the back plate. On my Sansui 881 it hits the back magnet at around half the volume making horrible noises.
I would be interested if it would be worth the effort to refurbish these by doing the following upgrades:
1. Replace the rubber surround with a rubber surround that has a wider bubble / bulge so that it allows for more flexibility and potentially bass. Original driver DW200/4 has wider bubble / bulge by 5mm as a consequence it does deliver more bass than this one.
2. Remove the back plate and add a metal ring between the magnet and the back plate that would leave more space for the core tube to move at the back. I'm only thinking of refurbishing these as I want to get more power out of the DM2's and these have a 700g heavier magnet than the DW200/2 original driver made by B&W in the 70's.
Has anyone attempted to do such extensive refurb. Would I risk damaging the magnet by trying to remove the back plate?
https://youtu.be/MIXDwRNceNo
This is a replacement driver stamped May 1993 and not the original DW200/2 bass driver designed by B&W the 70's. Limited play in the cone can be observed as the coil tube hits the back plate. On my Sansui 881 it hits the back magnet at around half the volume making horrible noises.
I would be interested if it would be worth the effort to refurbish these by doing the following upgrades:
1. Replace the rubber surround with a rubber surround that has a wider bubble / bulge so that it allows for more flexibility and potentially bass. Original driver DW200/4 has wider bubble / bulge by 5mm as a consequence it does deliver more bass than this one.
2. Remove the back plate and add a metal ring between the magnet and the back plate that would leave more space for the core tube to move at the back. I'm only thinking of refurbishing these as I want to get more power out of the DM2's and these have a 700g heavier magnet than the DW200/2 original driver made by B&W in the 70's.
Has anyone attempted to do such extensive refurb. Would I risk damaging the magnet by trying to remove the back plate?
https://youtu.be/MIXDwRNceNo
what does "proper" mean?
As I've already mentioned they have been taken out of a pair of vintage B&W DM2 speakers. Don't know whether that qualifies as "proper".
As I've already mentioned they have been taken out of a pair of vintage B&W DM2 speakers. Don't know whether that qualifies as "proper".
I want to know what enclosure are they in, now.
You show them in free space, over a piece of cardboard.
Which matches your symptoms.
Enclosures limit speaker excursion. You need to put the speaker in a box that's designed for the speaker you are using.
Some speakers don't like at all being in free air and you risk damaging them that way.
Do you have any way of measuring TSP parameters?
Some speakers don't like at all being in free air and you risk damaging them that way.
Do you have any way of measuring TSP parameters?
don't know what "TSP parameters" mean and I only have a multimeter as a "tool".
The speakers behave in the same way regardless whether they are in the DM2 cabinet or in free air.
Also I've seen other speakers in my life but never one that comes to an abrupt end making that knocking sound when pushed in. When I say "On my Sansui 881 it hits the back magnet at around half the volume making horrible noises." I mean that I play it in the speaker enclosure and not in free moving air.
Here it is:
The speakers behave in the same way regardless whether they are in the DM2 cabinet or in free air.
Also I've seen other speakers in my life but never one that comes to an abrupt end making that knocking sound when pushed in. When I say "On my Sansui 881 it hits the back magnet at around half the volume making horrible noises." I mean that I play it in the speaker enclosure and not in free moving air.
Here it is: