Repair of Speaker BNS 384

[John55]

Hallo everybody,

I have a problem with my BNS 384 speakers (bought in the 80's)
It are threeway closed box floor standing speakers
Crossover 500/5000Hz
Impedance: 8 ohm
freshrate: 28-22000Hz
+/-3dB: 40-20000Hz
sensitivity: 89dB
Piek power: 130 Watt
Power rating 20-100Watt

One of the bas drivers (woofer) suddenly stopped producing any sound.
There are no defects to see and the driver can easily been moved by hand, it also doesnot make any sound when doing so. The crossover is ok (checked)

I cannot find out what brand it is, perhaps enyone can help me by that.

It is a 263mm (10 inch) bas woofer
pitch 253mm (8X5mm holes)
The marks on the back (of the magnet) of the driver are:
M25WN-41
111530-6 8 (ohm)

Can I still buy a replacement driver for this speaker or what to do else?
Please advise!

 

[reubensm]

take a regular multimeter and check the resistance across the speaker. if you have an open circuit, these are the probabilities:

1) you have a burnt voice coil
2) the voice coil contacts which are soldered to the contact wires of the speaker (attaching the connectors to the cone area) may have given way (near the cone area), check if this can be fixed. I have fixed these on speakers in the past.

if you have a burnt voice coil, these can be re-wound, however I honestly feel the local speaker repaires in India dont have the competance to deal with such issues. they'll end up doing something which will play but the sound coming out will be questionable.

original replacements may be hard to find but if you change one, you'll have to make a corresponding change for the other channel also.

 

[John55]

Thank you for responding.
I think now it is a burnt voice coil and reparing is difficult.
Changing both drivers is the best solution then.
At this moment i don't now what driver is a good option, do you have a suggestion, perhaps Peerless 10" SLS-263 (has a high Qts, is important for closed box i think)

 

[reubensm]

Thank you for responding.
I think now it is a burnt voice coil and reparing is difficult.
Changing both drivers is the best solution then.
At this moment i don't now what driver is a good option, do you have a suggestion, perhaps Peerless 10" SLS-263 (has a high Qts, is important for closed box i think)

In my opinion, the Peerless driver is pretty good. If you are a little more adventerous, you can always pick up pre-used drivers with similar specs from ebay. You can usually choose from a wide range of Altecs, B&Ws, JBLs and more.

 

[Input2]

Check the coil with a VTM or a 9 volt battery and just touch the speaker terminals, you should be able to hear a tick.
It's really unusual that a woofer would quit like that. In all my 40 years I have seen plenty of tweeters do that, but never a woofer.