DCM Time Window rebuild

[Ricky77]

Hello Dr.,
I've seen your post on AudioKarma and your speakers look great. I'm about to restore one pair of TimeWindows 1, just the capacitors, so my question to you is: did you feel that replacing the capacitors was an important thing to do? I know that capacitors, specially old ones go bad with time. There is a video in YouTube with Steve Eberbach (https://www.youtube.com/watch?v=kI1RVjwEAGc) and he mentions that replacing the capacitors is a good idea. By the way, I'm looking for detailed information about how to remove the caps to access the crossovers, can you help please? Thanks

 

[eriksquires]

Hey Ricky,

I don't know DCM's specifically but you might want to look at my blog post about doing crossover mods here.

Best,


Erik

 

[Ricky77]

Thanks!

Erik:

I looked into the article and it has good information. What is your experience working with crossovers?

 

[Ricky77]

Hello!
I was reading to this post and I was wondering about your speakers. How has your project, did it worked?

Thx

 

[eriksquires]

Hi Ricky,

I write about a lot of speakers, so not sure which you mean.

The SNR 1's are fabulous to me. Search for Mundorf and ScanSpeak in this forum and you'll read a lot about the measurements especially about that tweeter.

The LM-1's are in development. The drivers and cabinets just arrived.

Once I can put the drivers in a cabinet and measure that's when the real X-Over fun begins. It will probably be a while until I can afford to order the crossover parts after that, but I should have the measurements and simulated results posted before then.

Best,


Erik

 

[eriksquires]

Erik:

I looked into the article and it has good information. What is your experience working with crossovers?

You'll find some real experts here in the DIY forum. I like to say I can get done everything I want to get done, but some like Bill Waslo, the author of XSim and OmniMic are the true geniuses around here.

System7 is not only very well versed in crossover design but in speakers that harken back to the bronze age.

Best,

Erik

 

[Clayx]

TW 35 years and still main system speakers.

I own a pair of DCM TW bought new in 81. I know the end caps glue on. I replaced one tweeter around 1985 and one woofer around 1993, both sourced from DCM. The woofer that went bad this time was the replacement from DCM. It had shielding, after calling and confirming it was the only option, it has let me down after 23 years.

NOS available or a known replacement? Please help, I don't want to throw a bad replacement in and destroy the exact sound. Back of 1993 replacement driver reads

160P0301

5 Ohms NOM 40W

DCM

Thanks.

 

[DrBoar]

Can you take a picture of the nonreplaced driver front and back? The Acccording to a cossover schematic and pictures TWA1A used a Philips AD 80xx. The Philips are plenty here in europe as they were used a lot back in the days.

 

[Clayx]

Thanks for the response.

Well it seems as my memory was incorrect and I had replaced both woofers in this unit. The other one is unmolested and I don't want to dig them out unless I have to. Here is the front of the undamaged unit.

An externally hosted image should be here but it was not working when we last tested it.

 

[JimBooth]

I have Time Window SN 994 and 1049 and QED 3715 and 3716. I plan to use them from front and rear speakers in a 5.1 surround system using a Marantz NR1402. The last time I used the Time Windows was for an outdoor karaoke party. This knocked one of the woofer dust caps off. I don't know for sure if it also damaged the tweeters, but I haven't used them since then which is some number of years ago. I glued the dust cap back on with a little gorilla glue and have been using them as front speakers for now. Voices sound quite muffled. A good example is the Spanish Princess. I've tried using the Audyssey calibration mic to try to bring out the best sound but it doesn't actually help. When I do manual equalization to boost everything above 1 or 2kHz it's better but still not good. After reading a lot here and other places it seems the problem might be old capacitors in the crossover, or damaged tweeters. If I put my ear by the tweeters I tell they are working but I can't tell if they are working as they should. I bought Peerless D19TD05-08 to replace the original Philips tweeters. The Peerless are replacements for the Vifa tweeters that DCM used in later and other models. The QED's have a similar muffled voice problem. I guess the first trouble shooting step should target the capacitors in the crossover. But if I aim to replace the tweeters I suppose I should copy the crossover from other models or later models of the Time Windows that used the Vifa tweeters. I guess one would be the TW1A? Maybe one from a Time Frame? I've found some crossover schematics but I don't really know what the best plan of action is. Ultimately I would put the TW's in front and the QED's in the rear. I have a pair of Polk Atrium 4's for the center channel.

So, if anyone has already gone through this I would sure like to hear your opinions on what to do.