Restoring B&W 2200

[fung]

This is the Crossover.

I have been out of electronics for 10 years (I have been doing IT networks, to put bread on the table) and do not have any current versions of schematic layout or simulator, hence the scruffy drawing.

Does anyone have the time and inclination to do a plot on this schematic? I hope this is not bad forum etiquette, but I am new around here.

I suspected there are something wrong about the position of C1, C2 and C3. Otherwise in this network, the bass unit won't deliver bass and will reveal a deep hollow in midrange.

 

[cliffforrest]

Thanks, Fung.

Later posts in this thread show the corrected schematic and a sensible plot.

 

[cliffforrest]

To conclude this thread:

Several days cycling the driver with about 2cm (max at resonance) excursion sweeping from 10 to 1000 Hz for three (!) days seems to have cured it

As I said in an earlier post, these B&W220Ds have not been used much in the last few years. After this "excercise" there is no scraping sound under any conditions I can detect using tones and test music (alan Parsons' Sound Check)

Thanks for all the help.

 

[cheltok]

i have this speakers in good condition
i note they sound different
i think i have to re cap the crossovers
it have a very strong and deep basses
i will recap and i'll post the results
can somebody tell me what means 10e-6 in the schematics?

maybe 10 uF or something?

cheers

 

[Everhard]

Help fixing crossover

Hi all, new here, looking for little help. I know this thread is quite the dinosaur but hey, thought I'd give it a shot...
I picked up a pair of DM330's for free - one of the tweeters not working. A quick test shows both tweeters actually work the problem is the crossover in one of the speakers. In fact in that speaker some one had previously replaced one resistor and did a brutal job of it... One leg wrapped around the edge of the board and soldered on the under side and the other simply wound around what was left of the leg of the old resistor... Not even soldered!
So I need to replace that resistor and I'm going to replace the same one in the other speaker - it doesn't look very good. Funny spots on it.
Am I right in thinking the resistor my finger is pointing to is a 5 watt 2.2ohm resistor?

Thanks!
E.

 

[ohdsp]

Yes looks like 2.2ohm

As you have them to pieces, and they are old, might be worth replacing those electrolytic capacitors.

 

[KatieandDad]

Earlier in the thread someone volunteered advice that Wilmslow Audio could supply replacements.

Any replacement driver would change the voice of the speaker. If the driver is faulty, I would recommend having it repaired. If it only needs the voice coil re-centring then that would not affect the voice of the speaker.

Similarly, be careful when replacing caps. B&W would have chosen the components with more than raw uF in mind.

 

[Everhard]

Thanks for the quick replies! I was considering replacing the caps as well, but given how easy it is to get to the crossover I think I'll first replace those resistors and then see how things work. If the speakers sound good at that point then I might just leave them alone.
I think the drivers are all okay - at least a quick test they sounded good. But further testing required once I've got those resistors replaced.
I'm in Canada - Ontario, need to see where to source the resistors here. I like to support local when I can! Otherwise I guess it'll be an online order...

E.

 

[ohdsp]

Similarly, be careful when replacing caps. B&W would have chosen the components with more than raw uF in mind.

True, I serviced a pair of B&W DM110 before, they had 9uF (two in parallel) in one channel in 10uF (single cap) in the other - in the same position. I did get lazy and replaced both as 10uF initially. Old caps measured low on capacitance. Speakers sounded good to me though once replaced so left them as both 10uF. Maybe wouldn't measure as well matched as new, but better than being worn out!


On resistors any 2.2R 5W ceramic resistor, or higher wattage, would work. Any decent electronics shop might have some (although they will likely just get them online).