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Whatever happened to DCM's Steve Eberbach?

post #1 of 1643
Thread Starter 
Just wondering. It seems that the current DCM company can not repair the Time Window Seven speakers. They have a few drivers left but they do not do work on the crossovers.

Any ideas on where he went? I may have a crossover issue.
post #2 of 1643
Try contacting someone at the Southeastern Michigan Woofer and Tweeter Marching Society, http://provide.net/~djcarlst/smwtms.htm who may be able to provide some contact information.
post #3 of 1643
Thread Starter 
Thanks, I'll give that a shot.
post #4 of 1643
Tracy, Steve is still in the Ann Arbor area. What problems are you having? I also have a set of the Sevens and I do have a copy of the crossover schematic for them. Steve has been working with me on a center channel to match the level of the TW7s. The new cabinet and drivers are done and I'll have the crossover finished in a couple of weeks when the rest of the parts come in. The four inductors for the time delay circuit was the hardest part to get right. All of their inductors were custom made at DCM. Steve is a great guy to talk to and very helpful. I try to absorb as much as I can. It amazes me on how he came up with the ideas in speaker designs that he did. As much as I've read on how impressed people were on the TimeWindows series (original's,1a's, and the 3's) very few have ever had the chance listened to Steve's signature series, the TimeWindow Seven's. All I can is say is "Steve, thankyou very much." Let me know if I can help.
post #5 of 1643
Thread Starter 
Hey Jamie,

I bought a pair of Three's new and have been amazed with them. I have been searching for a pair of Sevens for three years. Only now have I found a local pair. Most that have been for sale, the sellers will not ship them.

As for my new pair, the left speaker is noticabily softer than the right speaker. I have my system calibrated with a sound meter and the left is +3 over the right speaker. The left is also slightly muffeled compaired to the right. I carefully pealed the cloth down to check the drivers. They are intact and have no visable damage and are working. My only thoughts were that the crossovers need repairing or the drivers might have been changed. I am driving the speakers with a Sunfire amp and I do not have the problem with my Threes.

Any thoughts? Thanks for your assistance. Are you a poster on the Tivo and Deal Database forums too?

post #6 of 1643
Thread Starter 
Originally Posted by Jamie Hauser View Post

Steve has been working with me on a center channel to match the level of the TW7s. The new cabinet and drivers are done and I'll have the crossover finished in a couple of weeks when the rest of the parts come in.

Keep me informed on this project as well. None of the DCM centers or surrounds can keep up with my Threes, much less the Sevens. I currently have a Tannoy S6C as my center. Fairly close sonically but throw it an action flick at near reference, it gets really scary.

Not in a good way.
post #7 of 1643
Tracy, I talk to Steve earlier today about your problem, he had a few suggestion.

1) Make sure that you don't have two rights or lefts (apparently there must have been cases where this has happened).
2) Check to see if the right and left are on the correct sides (on the TW7, the outboard drivers are 6 db lower that the inside drivers. If you room is not symmetrical-one speaker closer to a side wall than the other- the one closer to the side wall will be louder).
3) Listen to make sure all seven drivers are working, including the rear firing tweeter.
4) Remove the crossovers from the speaker and check for damage. Steve said that they had a pair shipped once upside down and dropped. You could break loose one of the lager inductors. To remove the crossover assembles you need to remove the terminal cup first, part of the crossover is attached to it. Once that is out, use a flash light to look inside. you will see a single wood screw holding one end of the main board down. After that the board lifts out. there is just enough slack in the wires to get it all the way out. Check for any loose spade connectors. I know there are three circuit breakers and one "light bulb"- check for continuity.

That should be about it.

The TimeWindow Seven used a custom made tweeter, it was diamond coated. Stereo Direct was selling them new on E-bay, I don't know if they have any left. I picked up some for spares. The 6.5" midrange drivers were custom made also according to Steve. The CX17 and CX27 (Ebay) used them also, if you need replacements. The woofers were off the shelf Vifa. The OEM grill cloth was from Trend Textile.

I hope this helps, and no I not the poster on the Tivo and Deal Database forums.

I'll let you know when I'm finished with the center speaker. I need to come up with a name for it. Maybe "TW7 Center"?

post #8 of 1643
Thread Starter 
Hey Jamie,

Thanks for your thoughts and running my situation by Steve. I do have one left and one right and I do have them on the correct side. The right speaker is the furthest from the side walls but it is 4db louder than the right. All drivers are working. I will pull the crossover tomorrow. I know how to check for continuity so maybe something will turn up there.

I saw the tweeters on EBay. I didn;t know if they were the originals because it states them as being 8ohm. I thought the TW7 drivers were 4ohm but if this is correct I guess the total ohm rating changes when all drivers are connected together.

Do you have any idea who made the tops? The black laminate is starting to separate on mine. I can glue them but I thought you or Steve might have a lead on them. I have been told there were two different versions. Do you know anything about it? Mine look like MDF coated with some type of black laminate.

Thanks for all the info. Please keep in touch especially with updates or photos of the TW7C. I would like to hear more about the drivers, configuration and how you are building the crossovers. Feel free to post or email me directly.

post #9 of 1643
Thread Starter 

I took the crossover out. I do not see a circuit breaker unless it is the blue plastic rectangular component that I do not know what they are. I see two of those. As for the light bulb, the filament is broken inside the tube. What is this used for? Could it be my problem? Looks like it would be a potential heat source. All spade connectors are properly seated. Thanks again for your assistance.

post #10 of 1643
Thread Starter 
OK, I might have answered one of my questions. Is the lamp used to protect the tweeters? If can not safely jumper it, where can I get a replacement?

I may as well get a source for the other circuit breakers as well if you have it. I am now assuming that the previous owner had a lot of fun with these Sevens.
post #11 of 1643
I noticed that Circuit City is selling DCM speakers online at a very affordable price. Is this the same company as the original DCM? Are they good speakers for the $?
post #12 of 1643
I know they went belly up for a period and then the name along with other rights was bought and DCM was resurrected. I'm curious whether Eberbach has any involvement with the present company. I'd appreciate any additonal info.
post #13 of 1643
Thread Starter 
DCM was bought out by Mitek, the makers of MTX speakers. They do not know much about the original DCM's products. I had called to get a schematic for the crossovers. The lady that I spoke with said they didn't receive much info on the original DCM's speakers. As far as the quality, I do not know.
post #14 of 1643
Tracy, the circiut breakers are the blue plastic boxes. They should reset automatically. Parts Express sell them if you need them, just match the rating of 1.75A. There should be three, two are stacked. The light bulb does protect the tweeters. The filament is very fine, is there continuity across it? All of the tweeters are on it. If it's blown, you wont hear anything out of them. The later CX17s used them but with a lower rating, the older ones didn't. I would suppose that you could bypass it, but you would loose the protection. I don't know of a source for replacement. The tops were subbed out. Your best bet would be to strip it, then have a auto body shop epoxy primer it, paint it black, then clear coat it.

Chu Gia, Steve is no longer associated with DCM.
post #15 of 1643
Thread Starter 
Originally Posted by Jamie Hauser View Post

The light bulb does protect the tweeters. The filament is very fine, is there continuity across it? All of the tweeters are on it. If it's blown, you wont hear anything out of them.

The filament is visibly broken. The tweeters still work even with the broken filament. There must be another path for the tweeter circuit. I did temporarily jumper the lamp closed to see if it made a difference. I could hear a noted difference in the sound but I had the volume really low, just in case.

If you and Steve do not know about a replacement I may try something unorthodox. From the best of my testing knowledge, the tweeter circuit is around 12 volts DC going through the lamp. I will get a 12 volt interior car lamp, and create a socketed "bridge" off of the crossover board for the lamp. If I am wrong on this let me know but I think it will work as long as I keep it around 1.5 amps. Any thoughts about that solution.

Also, I am dieing to hear the details of the TW7C. I had actually thought about using one tweeter, one 6" and one 8" driver from DCM to create a center. I was not sure how to go about the crossover. What is your plan? I did buy the last three tweeters from Stereo Direct.
post #16 of 1643
Thread Starter 
Oh, I forgot to ask. What does the potentiometer do?
post #17 of 1643
Tracy, the tweeter circuit runs through the bulb, nothing runs parallel with it. Did you actually check it for continuity? Steve said if it is indeed open, you can bypass it with a .68 to .75 ohm resistor. If you want to replace it, make sure that the bulb has a welded filament otherwise you will add distortion. The best solution may be to buy a used CX17 for parts. The bulb in that is rated at 1.0A instead of 1.4A. You would have the protection, but at a lower level. The 6.5" driver is the same used in the seven. The wire wound pot is to attenuate the tweeter level.

The design on the center channel is based off the CX17. The new cabinet is made from 1" black walnut that was stain black with Indian ink and finished with 7 coats of polyurethane, wet sanded and wheeled. From a few feet back it looks like a piano black finish, when you look close you can see the wood grain. The front and middle baffles are made from 1/4"lead laminated with 1/8" dense vinyl. The rear baffle is 1/2" thick, removable and made from just laminated vinyl. The cabinet has the same look as the CX17 with the chamfered edges but is longer and deeper. the internal volume was increased by 10% (Steve said that the original design for the CX17 was made 10% smaller for better use of stock materials). It still uses the 6.5" diver (the same as the Seven) but the tweeter was upgraded to the ones used in the Sevens. It is diamond coated and the magnet is larger. The crossover uses the same circuit board as the CX17, but two of them like in the Sevens. I saved the low pass inductor, the circuit breaker, the dampening circuit inductor (which had to be rewound), and the bulb. To upgrade to the Seven's level you have to change the values of the cap and inductor in the dampening circuit for the new tweeter, add the delay circuit (which includes four inductors, seven caps and one resistor), add a 5 ohm pot and a 10 ohm resistor in parallel to the one tweeter to compensate for dropping the other two out from the Sevens design. All the resistors are Mills. the caps are all Panasonic polypropylene except for one Axon for the high pass and one Blackgate in the dampening circuit. The inductors used in the Sevens used spools with powder iron cores all custom wound at DCM. The problem was that the four inductors used in the delay circuit need to be spaced properly because they interact. The inductors are not available so I had to cannibalize the inductors from four other CX17 I previously bought for parts, strip them, and rewind to the new values. I used the same layout on the boards then for the new crossover. The cabinet and grill are done. I'm waiting on some parts to finish the crossover. When I'm finished, Steve offered to come over test it against the Sevens and tweak it, if necessary. I'll try and take some pictures tonight and see if I can figure out to post them.
post #18 of 1643
Thread Starter 
The bulb does not have continuity but the tweeters work. Also, I only have two of the blue circuit breakers on mine. Maybe I have a larger problem.

post #19 of 1643
Tracy, were circuit breaker #1 is there should be two 1.75A stacked in parallel. These are strictly for the woofers. #2 takes care of the mids and tweeters. The pot on the the board is not for the tweeters. The one for them is mounted on cup marked 'spectal balance" along with low and mid adjustments. The pot on the board looks like it in the band pass filter, it should be 5ohm 5W. I would have to check with Steve. After the #2 circuit breaker, one side splits to the midrange drivers and the other side goes to a 3.0 uf cap (the high pass filter), the light bulb, the pot on the spectal balance cup, then splits off for the dampening and delay circuits for the tweeters. You shouldn't be getting anything from the tweeters in the bulb is bad. Remove the board and see if maybe someone bypassed it underneath. Also, part of the tweeter circuit is on the board mounted to the back of the terminal cup. What are the positions of the pots on the spectal balance controls? Are they the same on both speakers. I would also pull the crossovers out of the other speaker and compare the wiring in case the previous owner tried to fix things himself. Good Luck

post #20 of 1643
Thread Starter 

I know what you are saying about the stacked circuit breakers. There's just one there. I looked at the other crossover for the right speaker and it too has only two circuit breakers. There are none stacked. The spectral balance knobs are as follows, left to right: full clock-wise, 12:00 position and full clock-wise position. They are both set the same. I have the calibration sheets that came with the speakers and they are set as they were calibrated at DCM.

I did find a schematic and see all the circuit breakers there, but I am one short on both crossovers. Maybe there was a revision for some reason. I did a quick test earlier. I used a jumper wire with alligator clips to close the lamp circuit. It made the highs even more muted and it sounded like the speaker was in a tunnel, slightly echoed with enhanced mids.

I am going to pull the lamp and replace it with a .68 ohm 2 watt resistor that I found locally. If that doesn't work, ask Steve if he would be willing to work on it. For a fee of course.
post #21 of 1643
Thread Starter 
OK, I put the resistor in place of the lamp. It brought the level of that speaker up. I haven't metered it yet but it is closer to the right speaker. It still does not have the "clarity" and "crispness" of the other speaker. I removed one of the tweeters. It had D23 printed on the back and K21TNM printed below that. Can you confirm this is the correct driver? I didn't want to pull the fabric down off the other speaker.

Thanks as always.
post #22 of 1643
Tracy, that's the correct driver. Does it have any hand written marks on it? Also, I would use a non inductive resistor of at least 5W. Percy Audio has a .68 and .75 ohm 5W (MRA-5) or .75 ohm 12W (MRA-12) made by Mills. It should make a difference.
post #23 of 1643
Thread Starter 
It has a R written on it. It was on the right side of the speaker. I guess the left one would have an L on it. What else would make the sound different? When I ran calibration test tones from my processor there was a big difference in the timber of the sound between the left and right speakers. I would assume they should sound the same.

Would the 5watt resistor make a difference in the sound or just the protection to the tweeters? Thanks for being my personal tech support.
post #24 of 1643
All the resistors in the the crossover are rated at 5W so I would use the same. It' not for protection. There is a resistant value for the light bulb, if you take it out of the circuit you need to compensate for it. That's what Steve did by suggesting that range of value. The important factor is the the resistor be "non inductive". It should make a difference in sound. I'm still concerned that you are getting any sound at all from the tweeters with the bulb blown. I would put both speakers side by side and pull the crossovers out so you could compare each wire on how it's connected. I you are good at following the schematic, trace the circuit. It's tough because the TW7 crossover is quite complex with 45 components.

No problem with the help. I've been fortunate that I've had help for good people, including Steve. It's just giving back were I can. Hey, us DCM fans have to support ourselves if the new DCM Co can't.
post #25 of 1643
Thread Starter 
More digging last night. Both crossovers are wired the same. I also looked at the tweeter board and no modifications had been made as far as I can tell.

I found a 12V 10watt lamp online. If my calculations are correct that would make it .833333 amps. Will that work or should I look into a resistor? I did find some .75 ohm 5 watt 1% resistors.

I had an interesting conversation with a local A/V shop owner yesterday. He carries some pretty nice stuff: Lexicon, Sunfire, NAD, Martin Logan, Tannoy, Runco.... He was also a DCM dealer and sold lots of Sevens. He said he had a pair come in with one of the crossovers broken. He called DCM to get a part to repair them himself. The tech he spoke with told him that they would pick the speakers up, repair and them reship them to him. He told the tech he wanted the specific part so he could repair it himself because he had multiple buyers for the speakers. The tech told him that he would be happy to send the part but it most likely would not sound like the other speaker after the repair. Sure enough, he replaced the part and the speaker sounded totally different that the other. He had both speakers sent back to DCM. When they came back they were perfect. The tech said that each pair was hand tuned and that sometimes different parts were needed to match them to their specifications. Two different sets of Sevens could have slightly different crossovers. Sounds strange to me but I am no audio engineer.
post #26 of 1643
Thread Starter 
The only lamp close that I have found is http://www.1000bulbs.com/product.php?product=5982

12 volt 18 watt, which = 1.5 amps. There is not mention about the filament being welded or not. It's a wedge base but it would not be difficult to make it work. I can not find the original lamp any where. Surely they were not custom made.
post #27 of 1643
Tracy, I would just stick with the resistor. Just make sure it's "non inductive".

I passed on the comment from your local A/V shop owner to Steve. This was his reply:

Looks to me like the technician did not have right equipment to match speakers to standard. Something could be broken and the only way to know what was broken would be to carefully analyze the speakers. I do not know if the new DCM still has the equipment needed. But MTX did take everything, just don't know if they kept it or still know how to use it.


post #28 of 1643
Thread Starter 
What does the non-inductive aspect of the resistor do for the circuit. They seem to be harder to find and Percy Audio has a $25 minimum.
post #29 of 1643
Try this site - http://speaker.rosaryshop.com/index.php/r/components. You'll have $2 for the resistor (Mills Resistor .68 Ohm 5W R-R68-5 ) and $8 S/H. I normal see if there is anything else I would need from a supplier like Percy because the small order is tough.

post #30 of 1643
Thread Starter 
Hey Jamie,

Are you using one of each of the drivers from the Sevens in the TW7C? What are the crossover points? Any photos yet? I'll obsess on your project as mine is on hold.

It seems that I have to play the waiting game on the resistors as the rosaryshop.com will not ship them until March 24th. I may try and call them in the morning to see if they can ship them sooner.

Also, if you have a clear copy of the crossover schematic could you email me a copy? My copy was faxed and it is hard to read all the component values.

Thanks !!!!!!!!!
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