DCM Time Window rebuild

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
WARNING! Extremely newbie questions to follow!

I am the original owner of a pair of Time Windows, circa 1977, which I would like to get working again. There is no sound coming out of any of the tweeters. Are they likely to be my problem, or is it more likely the crossovers? I have contacted DCM, and they have a suggestion for replacement tweeters (PartsExpress, part number 264-500). Has anyone out there attempted to work on rebuilding these speakers? Or, can anyone recommend a shop in the San Francisco bay area?
Thanks in advance,
Dan Clark
 
I don't know of any shops for that sort of thing, but I've always done my own repairs, being a DIY'er.

If all the tweeters suddenly stopped working, it's probably either a loosened connection somewhere, or a blown crossover component. It's possible they have a fuse (or lightbulb) that's blown. I recall listening to time windows a long time ago, but don't remember much about them, so I can't really help with specific details.

GB
 
Dont take the tops off!!!! The grille cloth comes off to reveal the speakers. The tweeters were old Phillips in most of the time windows and the are really bad. You most likely have blown them and not the crossover. Get the Parts Express parts and put them in and you will be ok.
 
You are probably correct then that the tweeters have blown. Doesn't peerless still sell a version of that philips tweeter? FWIW, I think they may have switched to seas tweeters in later years.

At any rate, those 3/4" vifas that DCM recommended don't sound bad at all.
 
Greg B said:
You are probably correct then that the tweeters have blown. Doesn't peerless still sell a version of that philips tweeter? FWIW, I think they may have switched to seas tweeters in later years.

At any rate, those 3/4" vifas that DCM recommended don't sound bad at all.
I've actually used the Vifa 3/4" domes in a TimeWindow repair and it was much better that the original tweeters.
 
yes take the tops off

You need to remove the tops to then roll down the fabric sock that covr the entire speaker. I had these speakers also and had to replace the tweeters also with 3/4" vifa.
The top wood cap should pop straight off, you mah need a piece of 1x lumber to gently tap around the bootom edge to loosen it up, then roll the sock down.
 
OK, I will order the vifa tweeters. While I'm at it, should I do anything about the woofers, wiring, or anything else? DCM no longer carries the woofers, tho' they know someone who recones them. Good idea, or not? I'm still trying to figure out how all the drivers are actually mounted. Is it possible to post pictures here?

Thanks for putting up with all the newbie questions,
Dan
 
Re: yes take the tops off

johnmark said:
You need to remove the tops to then roll down the fabric sock that covr the entire speaker. I had these speakers also and had to replace the tweeters also with 3/4" vifa.
The top wood cap should pop straight off, you mah need a piece of 1x lumber to gently tap around the bootom edge to loosen it up, then roll the sock down.
The time windows I've run accross did not need the top removed to get the grille cloth off.

The woofers were screwed and 'gooped' in and I had to use a razor blade to cut the sealant to finally get the drivers out.
 
I would get the grill cloth out of the way and then remove the drivers making note of the polarity of the connections to the drivers.
Then you could test each driver by hooking it up directly at LOW volume. This will at least tell you which speakers are blown out.
I would not order any drivers until you at least pull them out and see what you have.
Some of the DCM's had tweeters mounted directly in front of the woofers.
 
OK, I'm going to try to post photos of one of the speakers. The grille cloth is held on by two wooden strips, which are fairly easy to remove. The tops and bottoms are definitely glued on, and there is no bolt on the bottom of this model. So I guess I need to attack the drivers. If I removed the goop around the woofer, I'm likely to find screws, maybe? On the tweeter, I've removed the tape, and 4 screws, but it's not yet removeable. I guess I need to do some more digging around it. If I sound nervous, am I ;-} I've never done anything like this before. Any advice appreciated. And if the photos don't show up, let me know how to do that.
Thanks,
Dan
 
It looks OK. Don't worry. A screwdriver under the outer ring should loosen things up. They are obviously gooped in with some sort of caulk. It will probably take a little prying. If your'e really paranoid, feel free to give contact for some help, as I'm in SF. But this looks pretty simple, it's just that they glued the tweeters in.

GB
 
So, I've managed to remove the tweeters. They are definitely not working, because when I directly connect my speaker cable to them, I get nothing (well, nothing out the tweeters - there is sound from the woofers). Someone mentioned noting the polarity of the tweeters, before I remove them. How do I do this? I can't figure that out.

DCM says to use the Vifa 3/4 tweeter, part # 264-500 at Parts Express. Would I get better sound from one of the more expensive tweeters? Or is that just looking for problems?

What's the best way to mount the tweeters? Should I try to find the black goop that DCM used originally? Is there a problem with using screws?

While I have the speakers somewhat taken apart, should I do anything with the woofers, crossovers, wiring, etc?

Thanks in advance,
Dan
 
You say the woofers are working OK?

I would look over the woofers carefully if they have foam surrounds, cause foam tends to deteriorate over time.
If the foam looks dried out or flaking, then they need additional work.
Sometimes you can coat the foam with a silicone product if they are not too far gone.
If they have rubber surrounds then they should be fine.

Is there any model number or info on your tweeters?
It will be important to try to match the impedance and efficiency of the replacements.


John
 
I'm as far from an expert as you can get, but ...

I don't know what foam woofers look like, but these woofers definitely look like rubber, to me. The tweeters say "Made in Belgium", and have a bunch of number on them. They're at home, so I can't check right now.

DCM recommended replacing them with a specific Parts Express Vifa tweeter. I was just wondering if I'd get beter sound by getting a more expensive tweeter.
 
I would not use the vifa 3/4 ' tweeters as they don't go low enough, my guess the x/over would be too close to the tweeters resonance as the originals were 1 in philips units, I would say look around on ebay they come up every now and again or otherwise go for a 1 in unit from another brand perhaps a soft dome those philips hard dome units were very sibilant and peaky and werent the best even back in their day imho:smash: iow you can do better other than that scrap the speakers and start again build something of your own design as these werent the best even in their day the drivers are very medi ocer I aught to know as a friend had a pair he couldnt wait to get rid of he almost had to pay someone to take them away:smash: btw the rubber surrounds on thode bass mids are pretty thin and do tear if overdriven as I repaired them for my friend before he got rid of them:smash: luckily I managed to source some surrounds from the usa forgot who I got them from if I recall it was a company in chicago specialising in making paper cones as an oem part and they used the surrounds on some of the cones..... cheers hope this helps TC:D
 
The original Time Windows come from around 1977, developed by Steve Eberbach and Bob Waterstripe. I have versions from around 1980, these use Philips tweeters, made in Dendermonde, Belgium. As far as I know the typenumber is AD0140/T. They were made in a 4 Ohm version (AD0140/T4) and an 8 Ohm version (AD0140/T8). I don't know which impedance was used in the original Time Window. The tweeters are both in parallel, so I guess it is the 8 Ohm version. Also the woofers are in parallel.
These tweeters are 1" high power dome tweeters. They are round (94.2mm diam.) with three screw mounting. They look different from the ones on your picture. From the Philips datasheet, they have a sensitivity of 94dB (1W, 1m).

I once blew the woofers of one speaker (DC on the amplifier output) and had to replace them, but at that time, around 1985, I was able to get replacement speakers, via the German distributor. The cones have a rubber sorrounding, no foam (no problem).

These are very nice loudspeakers. Later versions have a more rectangular shape, but are also called Time Windows, only with a higher number. The one you have are the Time Window 1, with the rounded top and bottom and cardboard like rear. You cannot remove the top and bottom, you have to remove the speakers from the front. This takes some effort because of the kit that is used.

Crossover frequency is 2kHz.

Steven
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.