DCM Time Window rebuild

[CAPTAIN SOLO]

I was singing karaoke with a NAD 200 watts amp. Both tweeters are now dead. Teh tweeters look intact, but are making no sound. The speakers sound dull and dead.

Are there any protection in the cross over circuit for the tweeters? Or are the tweeters just blown?

What part of the cross over circuit should I replace to have the tweeters working again?

[CAPTAIN SOLO]

Mine was the 1s bought in 1977. I used them for karaoke with a NAD 200W amps. Both tweeters are dead. Speakers sound very dull.

The cross over circuit looks like this pic. I dont see any fuses or light bulbs that were supposedly protect the tweeters.

One of the first posts in this thread said factory suggested replacing the tweeters, not repairing the cross over. So the tweeters must have been blown.

The tweeters are round with 3 mounting screw. I removed the 3 screws, but the tweeters are not coming out. Anybody knows how to remove the tweeters?

Originally Posted by amt

Well I finally started to redo my TWs. I removed the top and bottom caps and cut the top of the speaker open with a sabre saw. If I didnt know the speakers were a commercial product, Id say they were fabricated in someones garage. Standard PVC, sonotube, Liquid Nails (lots of that) and a pretty ugly XO.
The pictures Ive seen of the TW1a and TW3 represent a big improvement in build and execution.

The crossover in particular is of interest since it appears nothing like the TW1a design. I will post it once I figure it out and draw it up.

amt

[amt]

There are no light bulbs or fuses used for protection. If you check post #60 you can see the entire crossover network. Its unlikely that components failed in both crossovers so you have probably blown the tweeters. The crossover is mounted to the top of the speaker. The Oak piece on top is glued and doweled to the actually MDF top plate of the speaker. It, in turn is nailed and glued around the perimeter of the speaker "tube". I removed them for access rather than a woofer since the woofers are glued in and a real pain to remove (so Ive read).

These are great old speakers but repair and restoration is a challenge due to their monolithic construction.

amt

[mrbubbles]

Hello, i am new here. Have been a DCM and audio fan for quite some time and am now doing my 1st DCM rebuild/ restoration on a pair of TW-1's. All my drivers are good. I plan on updating the xovers but am not sure exactly what I will do to it yet. From that I mean that I have read that the driver complement and part #'s are the same for the TW-1 and the TW-1a's but can't find any definitive proof of that to date. The #'s on the bass/ mid drivers from my cabinets are 4846SD printed above the # 575206 and the tweeters #'s are AD 0140 T8 printed above 2422 257 33202 which is printed above DD10 127 111. This last set of 3's is the same on 2 tweeters and on one of the others it is DD10 122 111 and on the last I can only make out the DD10 1?? 111 as it is printed over the indent on the center of the magnet. I assume the tweeters are the same as the 1A's as I have found where the 1A's use the AD0160 or AD0140 which seems to match. The numbers I have found for the 1A bass/ mid drivers is AD80xx as given in a diagram in this thread which doesn't seem to match or even relate to any #'s on my drivers. I guess my point being is if the two models use the same drivers and same cabinet but the 1A uses an updated (possibly better ) crossover why not try to match the crossover to that of the 1A instead of the original 1 if the correct inductors can be found. Either way i plan to build new end-caps with the bottom endcap acting aas a base/ riser and mount the x-over external to the cabinet inside the base for easy access. I will performing other upgrades/ mods to the cabinets as well but am trying to get my complete game plan together so as to order necessary parts. Also for future purposes, does anyone have the detailed specs on this tweeter. Since this type diaphragm is so readily available, in many different materials, etc. it may be worth experimenting with different diaphragms if some can be found with suitable specs. Does anyone have a schematic for the TW1 crossover which includes values for the inductors.

[mrbubbles]

not sure that it matters but i noticed that the clock on the post timer is off. I made my last post at approximately 9 am on 2-22-12.

[Speedskater]

Mr. B if you scroll down to the bottom of this page, you will see a messages: "All times are GMT -x" and "The time now is xx:xx AM/PM". You may have the wrong time zone selected in your User CP. If you don't log-in the time will be from the forum host's time zone.

[mrbubbles]

Originally Posted by Speedskater

Mr. B if you scroll down to the bottom of this page, you will see a messages: "All times are GMT -x" and "The time now is xx:xx AM/PM". You may have the wrong time zone selected in your User CP. If you don't log-in the time will be from the forum host's time zone.

Got it.

[krigby]

I have two pairs of TW 1's and I have been considering replacing the caps in at least one pair. But I can't figure out how to get them apart. is the X-over accessible from behind the woofers? If not, how do I get them apart to get at the X-over?

[CAPTAIN SOLO]

The crossover circuit is on a terminal board which is glued down onto the top, inside the speaker.

The decorative top plate is pin doweled and glued down on the top of the speaker. To remove, knock on the edges with a hammer. You will see the flat top of the speaker glued flat on top of the tube. The only way to remove the top to get at the cross over is to pry it at the edges of the speaker tube with flat head screw driver.

there will be some damages to the edges of the top and side of the speaker tube, but can be repaired with wood glue.

[CAPTAIN SOLO]

The original Time Window speaker was on the market around 1975. Each speaker uses 2 philips tweeters #AD 0162 T8 MYLAR DOME, made in Belgium. It's supposed to take up to 80 Watts peak power. But it can be easily blown if used with high-transient sources like singing karaoke etc..

The tweeters can be replaced with a drop-in tweeter, the Vifa D19TD-05 3/4" Poly Dome Tweeter, bought on line for about $16.88 each from Parts Express web site:

Vifa D19TD-05 3/4" Poly Dome Tweeter 264-500

Procedure to remove and replace the tweeters of DCM Time Window speaker:

1. Remove the foam cover by laying the speaker face down and pry out the 2 long wood strips.

2. Roll the speaker with drivers facing up, remove the tweeter by inserting a flat head screw driver into the edge of the tweeter's black, round plastic face plate and pry it out. The face plate is glued down with wood glue so it comes apart easily.

3. Cut off the end of the wires at the tweeter's terminals. Mark the copper/red wires that should go onto the positive terminal, and the silver/aluminum wires that should go to the negative terminal.

4. Solder the positive wires to the positive terminal and then the negative wires.

5. Lay a bead of caulking around the edge of the tweeter hole.

6. Press the Vifa tweeter all the way down into the round hole so it sits securely into the caulking.
5.