Help Please! Recommendations for SBL Bass / Mid Rebuilds

Clive, that looks like one of the original Mordaunt-Short mid/bass drivers. Possibly it's a good idea to consider upgrading to the later, much improved, Naim drivers.  I'm not sure whether Naim can still supply them (your Naim dealer should be able to find out), but they do turn up secondhand every now and then.

Yes your clip does show the buzz to full effect

Does sound like you will need a new one (pair)

Are the mounting bolts torqued? I’ve not had buzzing from my Naim speakers but when my Thiels started to buzz thightening the mounting bolts cured it.

Just read the OP properly and looks like you had that covered.

If you haven’t already, you could try swapping the driver between the two cabinets - that would prove whether or not it is the drive unit itself. I don’t know how they are sealed simple gasket or other - and care will need to be taken to re-make the seals, but that won’t affect the check, and would need doing anyway if you do end up having to change the drivers.

Innocent Bystander posted:

If you haven’t already, you could try swapping the driver between the two cabinets - that would prove whether or not it is the drive unit itself. I don’t know how they are sealed simple gasket or other - and care will need to be taken to re-make the seals, but that won’t affect the check, and would need doing anyway if you do end up having to change the drivers.

While I haven't swapped the drivers, I have switched left & right channels - its definitely the driver

Might be worth having a chat with the folks at Wembly Loudspeakers. May be that they can repair to original specification, especially if Naim could provide any necessary details.

Willy.

Clive Gidney posted:

While I haven't swapped the drivers, I have switched left & right channels - its definitely the driver

I was thinking driver specifically as opposed to something in the cabinet? (i don’t know how likely that might be.)

Willy, it's a not a Naim driver, but one from Mordaunt-Short. As I say, it may be best to get some Naim drivers - it'll be a nice upgrade too.

Richard Dane posted:

Willy, it's a not a Naim driver, but one from Mordaunt-Short. As I say, it may be best to get some Naim drivers - it'll be a nice upgrade too.

Maybe a nice upgrade but I've been quoted £775 - ouch! Probably more cost effective to buy a pair with the Mk 2 drivers & sell these for spares

Innocent Bystander posted:

Clive Gidney posted:

While I haven't swapped the drivers, I have switched left & right channels - its definitely the driver

I was thinking driver specifically as opposed to something in the cabinet? (i don’t know how likely that might be.)

It's possible

I had a problem with one of my Kudos C20's, very very occasionally you could hear a weird buzzing noise triggered by LF energy.  Meet Me In London always triggered it.  I contacted Kudos and they advised that it was the cable resonating against the cabinet inside.  They talked me though removing the driver and re-positioning the cable.  Problem solved!

trickydickie posted:

It's possible

I had a problem with one of my Kudos C20's, very very occasionally you could hear a weird buzzing noise triggered by LF energy.  Meet Me In London always triggered it.  I contacted Kudos and they advised that it was the cable resonating against the cabinet inside.  They talked me though removing the driver and re-positioning the cable.  Problem solved!

Interesting.  Someone on another forum suggested that the suspension might have sagged so I've had the driver out & rotated it through 180° - that will have re-positioned the cable. No change

Clive Gidney posted:

Richard Dane posted:

Willy, it's a not a Naim driver, but one from Mordaunt-Short. As I say, it may be best to get some Naim drivers - it'll be a nice upgrade too.

Maybe a nice upgrade but I've been quoted £775 - ouch! Probably more cost effective to buy a pair with the Mk 2 drivers & sell these for spares

Or have a ring around some of the more likely Naim dealers.  They must have done a number of SBL Mk2 driver upgrades over the years, and maybe they have a spare set of the originals stored away going for cheap.

In fact maybe only one needed! (But If me I would suggest double checking it is tpthe unit itself.)

otherwise there are specialist companies around that will rebuid drivers, replacing te voice coil  or whatever may vpbe rubbing. Whether they can do that particular driver is another question- search around under ‘re-coning’, and a bit of a niche area. I had a drive unit done by somewhere in north west London (someone mentioned Wembley?), but that was an Altec Lansing 15 inch pro unit, and was about 35 years ago...!

Innocent Bystander posted:

In fact maybe only one needed! (But If me I would suggest double checking it is tpthe unit itself.)

otherwise there are specialist companies around that will rebuid drivers, replacing te voice coil  or whatever may vpbe rubbing. Whether they can do that particular driver is another question- search around under ‘re-coning’, and a bit of a niche area. I had a drive unit done by somewhere in north west London (someone mentioned Wembley?), but that was an Altec Lansing 15 inch pro unit, and was about 35 years ago...!

The company you are thinking of is Wembley loudspeakers , who are actually in Shepherd’s Bush near Askew Road . I know the company very well as one of my closest friends worked there for 20 odd years . It’s pretty much one guy these days but he really knows his onions . 

Sounds like you picked the best option and I'm glad it's all sorted now 

Great news! I love it when there are independent specialists doing stuff like this..My BMW differential started to whine - £1900 if fitted at BMW but rebuilt by a gearbox specialist for £550 

sjw posted:

Great news! I love it when there are independent specialists doing stuff like this..My BMW differential started to whine - £1900 if fitted at BMW but rebuilt by a gearbox specialist for £550 

My Audi A4 has got a differential problem, Audi want £4300 for a new one, what specialist did you use?

Nick

am gearboxes near Reading. Often he's under a car so can't answer phone but really knows his stuff. Small chaotic workshop but a refreshing change from over polished expensive main agents!