Old B&W DM220 drivers....

[racedirector]

Howdy all

The DIY bug has bitten now that the kids are grown up, cars are done and I have time....

I have the old drivers out of my old B&W DM220's. They weren't bad speakers but a blown tweeter in one and torn driver cone in another put paid to them as a pair.

I have left 3 of the drivers (BZ200/16) and one tweeter (RZ26) - what I am hoping is that I can build something out of these. Being *very* new to the DIY scene can anyone suggest some tweeters to use and maybe a suitable crossover. I only ask as I have no idea what to look for at this early stage. Of course there is also the option that entails not using the drivers because they are useless - if that is true then they will probably just become something to chuck in the garage.....

Any help with this initial little project would be appreciated.

Cheers
Bruce

[Shaun]

Hi Bruce

Do you think you could repair that cone with some paper/wood glue? It will work if the tear is not too bad; just realign the broken bits and then apply the glue, letting it soak into the paper.

To get the best from these drivers I would mate them to a Dayton RS52 mid and budget tweeter (I was once in the same position you are, except that both tweeters were fine, though the torn cone was repaired in an unsightly way).

See zaphaudio.com for some comparative test results and projects.

Good luck

[kipman725]

Don't B&W sell replacment drivers? I managed to get 25 year old drivers form mission audio. Worth emailing them if you liked the sound.

[racedirector]

Hi Shaun

The tear isn't too bad, it actually looks like I tried to repair it at some point as the tear has tape (!) on the back of the cone. I will very carefully try and remove that and go with the wood glue.

Am I reading you correctly in assuming that I can use a pair of those with a Dayton and a budget tweeter - e.g. Hi-Vi SD1.1A tweeter (only know that one because it is in a project I would like to build one day over at diyaudioprojects.com) or do you mean use one driver with a Dayton & tweeter?

I also had a look over on zaphaudio.com but they were a little above my head. Any further suggestions would be greatly appreciated.

Cheers
Bruce

[racedirector]

Originally Posted by kipman725

Don't B&W sell replacment drivers? I managed to get 25 year old drivers form mission audio. Worth emailing them if you liked the sound.

A little too late for that I'm afraid, I butchered the cabinets a few years ago when I was playing with other drivers. The drivers, tweeter & crossovers is all I have now....

Cheers
Bruce

[racedirector]

Just reviving this thread, I would like to try a simple 2 way with these drivers. If I grab, say, a Jaycar tweeter (ct2009) can anyone suggest a simple project to do as a starter DYI using 1 driver and a tweeter per box. Suggestions on a crossover would also be appreciated.

I would be driving these initially with a 100w amp and them (maybe) later a Gainclone.

Off course, if anyone has any other configuration suggestions, they too would be welcome although it has to be a budget type solution just to "play" with.....

Hoping someone can help.

Cheers
Bruce

[Shaun]

Any generic crossover recommendation would not give you the optimal result, as the crossover has to be custom designed for the specific enclosure and driver combination. See if you can trace a fellow DIYer in your area who has measurement capability. You'll need to firstly determine the Thiele/Small parameters of the woofer, design your enclosure, mount the drivers and then do the acoustic measurements before getting down to the crossover design.

[racedirector]

Thanks Shaun

I think it is becoming pretty clear that I should just sell all these drivers to someone who needs B&W spares. I neither have the resources or know how to accomplish DIY of this level.

Anyone that needs a driver for the aged B&W speakers, please contact me - I have 3 BZ200 woofers available.

Cheers
Bruce

[Shaun]

My intention was not to discourage you. There are many successful designs that were done "by ear" and rule of thumb: you can still try this approach. For instance, someone who has used the Jaycar tweet could identify a minimum crossover frequency for the driver, and you could work from there...

[thomsva]

A simple solution would be to buy a plate amp (for example Hypex DS1.2) and use the bass drivers to build a subwoofer with all four drivers. If you can't or don't want to measure the drivers you can just build the subwoofer roughly the same size as the original DM220 (=double that if you use all four drivers). If you make the enclosure sealed I don't think you can go wrong. The result may not be perfectly optimized but it will be very good value for money.