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Whatever happened to DCM's Steve Eberbach? - Page 29

post #841 of 1643


The base has a ¼" radius cut made into the top edge that is a ¼" deep x 3/8" tall.



After that, the hole are drilled for the five spike locations (9/16" dia. x 7/8" deep, outer holes) and the four mounting spots (5/8" dia. x 5/8" deep with ¼" dia. hole through, inner holes).




Topside showing the through mounting holes.
post #842 of 1643
Trial fit of top and base.



post #843 of 1643
Thread Starter 
Pretty amazing Jamie. I am interested in seeing how you finish those tops and bottom plates. Are you building these for yourself just to compare to your original Sevens, or did Steve put you up to this.

Keep the photos coming.
post #844 of 1643
Quote:
Originally Posted by Tracy RainH2o View Post

Pretty amazing Jamie. I am interested in seeing how you finish those tops and bottom plates. .

The finish is going to be the same as the TW3 make over. http://www.avsforum.com/avs-vb/showthread.php?p=8657760&highlight=the+tw3+make+over#post8657760

The primer is a two-part PPG (DP90) automotive paint. After sealing, all parts receive two coats of black (PPG), and then three coats of two-part clear (PPG). Wet sand the painted parts with 2000-grit paper then wheel out.

Quote:
Originally Posted by Tracy RainH2o View Post

Are you building these for yourself just to compare to your original Sevens, or did Steve put you up to this.

Keep the photos coming.

This is something that I’ve been wanting to do for years (I’ve been collecting parts for quite a while) and for many reasons. These are remarkable speakers and as Steve has said, that they took the TimeWindow technology as far as they could go. Truly his "signature series", at the time (I still think he’s got at least one or two better design in him). They have been a challenge to build so far, not just with my limited resources, but to find as many of the original parts and keep it as close to the original design as possible. Because they are such a complex design and without the original test equipment (or the knowledge of how to use it), my success is completely dependant on matching what was done at DCM. I don’t have the luxury of straying off for the sake of convenience. What very little I have (small improvements), was done with Steve’s advice. My ultimate goal here is to have four matching TW7’s in a quad formation (4.2) for multi-channel music (I’ll still maintain the center for 5.2 multi-channel and 9.2 for home theater). In particular for Alan Parson's quad mix of DSOTM. The cleaned-up version in the new "immersion set" is extraordinary. It really is all about the music.
post #845 of 1643
The fluted sides were more work than I anticipated, but I’m happy with the results.



They are 2-7/8" wide and were cut from 3/4" MDF stock. Because the backsides have an 18 degree bevel (which is an acute angle when you rip on a table saw) with a 1-1/8" land on the back and 1/4" on the sides, this required cutting the bevel with the piece on end. The only way that I could see to do that was to use double sided foam tape and combined two pieces back-to-back. The photo shows one piece with the two bevels cut.



This photo shows the 1-1/8" land cut on one of the pieces.



Here are the four sides completed with the four 3/8" flutes that are 5/8" on center and a 1/8" deep. They stop a 1-1/8" from the top and 2-1/8" from the bottom. Also shown are the Mod-ezz mounting clips on the back of two of them.
post #846 of 1643
Some misc. photos of the flutes in place.







Showing the mounting points.



Here's a picture of the original and the new.


post #847 of 1643
The next step is to install the wiring harnesses and acoustical stuffing, which normally would have been done before the last front baffle, was put into place



The wiring harnesses are made up of three separate components. The main one is for the two 6-1/2" midrange drivers and the three tweeters. It is 57" long and made up of white, red, blue, brown, green, black, orange, and yellow NTE Electronics 20AWG, 300V, SP/25, STRND Hook-Up Wire.
The second is for the two 9" woofers. It is 43" long and made up of red, brown, black, and yellow NTE Electronics 20AWG, 300V, SP/25, STRND Hook-Up Wire.
There is a single 21" long wire that is black with a yellow strip that goes between the neg. side of the outboard tweeter to the pos. side of the rear tweeter.
All the ends are terminated with either FASTON 42068-1 (Stud/Tab Size:0.11 x 0.02"); or 42710-2 (Stud/Tab Size:0.205 x 0.02"); Crimp Connector Female Disconnect, Wire Size (AWG):22-18; Contact Material:Brass; Contact Plating:Tin, depending of what they're connecting to. Tip-of-the-hat to Jamesblues for identifying these connectors.




Close up of the main harness showing the terminations.



The same for the second harness.
post #848 of 1643
Here are a few photos showing the harnesses installed.





This one is the main harness in the top section that houses the midrange drivers.
The second shot is the rear tweeter location in the same section.



And under in the woofer section.



This one shows both cabinets with the appropriate wires protruding were there drivers would be. Note that the color coding of the wires are mirror image of each other. The penetrations into the midrange section and to the outside for the tweeters are sealed with hot glue like the factory did.


Also note the acoustical stuffing for both the midrange (7-1/4 oz.) and woofer (8 oz.) sections
post #849 of 1643
There is also acoustical stuffing near the port tube and the filling the 8" hole in the first internal brace just above the section that holds the crossover board.





This is the left speaker were both wiring harnesses go pass the port tube on the left side. The acoustical stuffing (7-1/4 oz.) is pushed just pass the port tube on the right side filling the void between the port tube and the outside wall of the cabinet and the rest lays over the top of the tube. I did the reverse for the right speaker.



Here is the acoustical stuffing (7-1/4 oz.) filling the 8" hole in the first internal brace just above the section that holds the crossover board. The opening is completely filled with the bulk of the acoustical stuffing "mushroomed" above the opening.

post #850 of 1643
Jamie,
I really enjoyed your Time Window 7 project, just awesome detail and precision there. Bet they will sound just as good as your assembly appears. Alot of hard work done there. Are you going to address the inner cabinet walls with any kind of damping material such as Soundcoat ??? etc.
Hey Jamie do the top/bottom caps in (Vette Torch Red) otherwise you just might get the originals mixed-up with yours ... ha.

A fantastic job, very envious.

Window3Time
post #851 of 1643
Quote:
Originally Posted by Window3Time View Post

Jamie,
Are you going to address the inner cabinet walls with any kind of damping material such as Soundcoat ??? etc.
Window3Time

No, I'm sticking to as close to the originals as possible.
post #852 of 1643
Next up are the crossovers.

This is really the only place were I'm making a slight upgrade and really only in a few ways. I'm staying with the original style wire wound cement resistors (made by Xicon) although tolerance will go from 10% to 5%. The electrolytic capacitors I'm using are made by ERSE and have a dissipation factor of 3% (except for the 200uF values which were only available with a D.F. of 6%) and tolerance of 5%. The original ones were 5% D.F. and 10% tolerance. The biggest improvement (Steve's recommendation) is upgrading the original film capacitors from Mylar (polyester) with 10% tolerance 100v to polypropylene with 5% tolerance 250v. The new film caps are ECW-FA series Panasonic polypropylene film capacitors for all the values except the 3.0uF's which are the ECW-F series that are being phase out in favor of the ECW-FA series (this series does not have the 3.0uF value which I needed 8 of them for this project).



The circuit boards used are the C91's that are used in most of Steve's later designs like the CX and TF series. These were donors stripped down from several crossovers that I have acquired through the years.



Here are all the inductors needed (I'm still short two of the largest ones) for the new crossovers. These are the most critical part of reproducing any of Steve's design because they were unique and made by DCM. Particularly their powder iron cores. In the little bit of studying (reading and talking with Steve) that I have done, trying to find a suitable replacement, I found that iron cores are different that inferior ferrite cores and that there are many different mixtures for iron cores that have an impact on how the inductor performs. Steve put a lot of work in designing these and I quickly realized that I could not build a substitute, I could only take the original inductors from donor DCM crossovers (there are 3 size based on core dia. and bobbin size) and strip the magnet wire and rewind them with the proper gauge magnet wire to the new values that I needed. I had to rewind all of them.



Here's the start of 2 new boards.


post #853 of 1643


This is one of the new ¼" plywood boards needed for the main board that is constructed with "Point-to-point" wiring next to an original.



Here is one of the sub-assemblies for that same board.
post #854 of 1643


This is one of the completed crossovers (note that only the large inductors have hot glue on them. I will hot glue the rest of the crossover parts after everything is properly tested.



One of the original for comparison (note the additional wiring that goes to the drivers that are not shown with the new crossover above).
post #855 of 1643
Miscellaneous close-ups.











post #856 of 1643
Back to the cabinets.



The baffle area surrounding the midrange and woofer along with the rear-firing tweeter needed to be blacked out.



After that the headliner material was applied. This is a 1/8" foam backed cloth that is attached with 3M Supper 77 multipurpose spray adhesive. Note the slot that is cut out were the Mod-ezz clips are used for the side panels. There is a full "sock" of speaker grill cloth that will be pulled over the entire cabinet later.



One of the cut outs for a terminal cup.




And another for the rear tweeter.
post #857 of 1643
Installing the drivers are next. The TimeWindow Seven have a total of 7 drivers (possibly where the name came from, but it also has 7 sides for that matter). Two 9" woofers, two 6-1/2" midrange, and three tweeters.





The woofers are Vifa's M22WR-09-06 top-of- the-line (at the time) 9" drivers. Used in several other high-end home speakers, including the $12K Manger Zerobox and Apogee Centarus.





The midranges are DCM's D16 6-1/2" drivers that were used in the KX series. This is basically the same driver used in the CX and TF Series Two but with the plastic snap ring instead of a gasket on the outer rim of the basket and a magnet shielding cup over the main and bucking magnet. It was the last incarnation of that driver design. The dimpled cones used in all of them were made by a Japanese company for DCM. Don't let the stamped steel basket fool you, this is a remarkable driver Steve design and is good enough for his signature series TW7.






The two front firing tweeters are DCM D23 that are similar in appearance to the tweeters used in the CX and TimeFrame Series Two but are diamond coated and use a much larger magnet. These were unique to the Sevens and not used on any other design that I know of. The rear-firing tweeter was a DCM D22, which is the same as the D23 except for the lack of the diamond coating. Steve said that this was strictly for cost saving. I will be using the D23 for the rear tweeter.
post #858 of 1643
Here are a couple of side by side comparison shots of all three driver types.



post #859 of 1643
Here are a few random shots of the drivers being installed.







post #860 of 1643
The crossovers, terminal cups and "Spectral Balance" controls are installed next.



The "Spectral Balance" controls are mounted on a modified terminal cup. This photo show the back side of a terminal cup that uses binding post as oppose to the ones with the spring loaded clips. The cup in front has the hole for the negative binding post filled (I melted/welded the same material into it from another terminal cup with a soldering iron) and sanded it out. The existing hole for the positive binding post is in the correct position for one of the variable resistor and just needed to be drilled out along with the holes needed for the other two variable resistors.



Here is the opposite side showing the variable resistors temporally installed (I used the nuts provided with them to hold them in place, the original ones are hot glued in place without the retaining nuts) and the fluted aluminum knobs. Those knobs were very difficult to track down and match to the originals. After about three years of on-and-of looking through online catalogs I was just about ready to settle for something remotely close just to do the job. I decide to Google "fluted aluminum knobs" but using the "images" option instead, and one of the first images was link to http://www.driveinmemories.com/index...products_id=26 for a perfect match and good price. It's funny how sometimes something that small of a find can give so much satisfaction.

The decal for the "Spectral Balance" control will be added later.
post #861 of 1643


Here are the crossover components wired to the drivers.



The main board installed. It just slips into to tabs in the front of the cabinet and has a single screw that holds down the other end near the opening.



And finally with the terminal cup installed.
post #862 of 1643
Beautiful Jamie!
post #863 of 1643
Good job and thanks for sharing - I have owned some DCM's
in the past - good luck and enjoy.
post #864 of 1643
Jamie I can"t take it anymore, your earlier project on the 3s and now this 7 total build has inspired me to get to work on my 3s. What I"m after is re-doing the caps ..... Yep in Torch Red, recapping the XOs and adding better binding posts. Back on page three of your 3 project you replaced the four electrolytic caps, plus the Mylar high pass caps with Solen polypropylene.
Jamie can you please give me the Electrolytic cap brand used and their values ??? Also the 2 Mylar high-pass values ???.
I would like to order the XO parts first, allowing me enough time to redo the top/bottom caps in paint.

Sincerely, Window3Time > Redford Twp.
post #865 of 1643
Quote:
Originally Posted by Window3Time View Post

Jamie I can"t take it anymore, your earlier project on the 3s and now this 7 total build has inspired me to get to work on my 3s. What I"m after is re-doing the caps ..... Yep in Torch Red, recapping the XOs and adding better binding posts. Back on page three of your 3 project you replaced the four electrolytic caps, plus the Mylar high pass caps with Solen polypropylene.
Jamie can you please give me the Electrolytic cap brand used and their values ??? Also the 2 Mylar high-pass values ???.
I would like to order the XO parts first, allowing me enough time to redo the top/bottom caps in paint.

Sincerely, Window3Time > Redford Twp.

Thanks,

To do both speakers you'll need four 100uF 100v and four 47uF 100v non-polar electrolytic with a dissipation factor of 5% or less. The best I've found are from ERSE; they have D.F. of 10%, 6%, and 3%. They stock the 100uF value w/3% D.F., but not the 47uF. I needed the same values for the TW7 clones and ended up ordering 22uF and 25uF values w/3% D.F. to combined them to make up the 47uF value. Here's the links: http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-100-0-PB, http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-22-0-PB, http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-25-0-PB .
They do stock the 47uF 100v w/6% D.F if you would rather not double up the 22uF and 25uF.
The high pass value is 3.0uf. I doubt that I would have changed them out again, I just had the Solen polypropylene lying around.
post #866 of 1643
Thank You Jamie,
Will take your advice and pass on the high pass Solens. Will go the simplier route with the 47uF w/6% D.F also. I forgot to ask your source for the quality binding posts ??? A good quality 3-way type. Thanks so much for the parts values and the link to erseaudio for my order. Its guys like you who help keep the DCM fire burning, with expert help and guidence. Again, thanks so much.

Sincerely, DW
post #867 of 1643
I was holding out on finishing the other crossover because I was still short two of the large inductors. With Ebay as my only source, I wasn't having any success lately. So not wanting to wait any longer (and desperate men do desperate things J ), I decided to make them. I had extra of the 3/8" powder iron cores (the same used in the midsize inductors) and the right gauge magnet wire (18 awg), all I really needed was the proper sized nylon bobbins. To make these I used 1/16" thick large nylon washers and 3/8" I.D. nylon sleeves (both with O.D.'s that were larger than I needed and the sleeves weren't long enough). I was surprised that nylon could be glued with CA adhesive. After gluing two sleeves together end to end and shortening to the right length, I glued the washers in place and ran a 3/8" bolt through the assembly and chucked it in the drill press to be turned down to the proper I.D.'s for the washers and sleeve. Here are the results.



This photo shows an original on the right and one of the new ones on the left before winding. The last two inductors use a longer iron core. One I had, the other I had to CA two together and shorten.



This photo is both wound to their correct inductance. It's interesting on how you can very the inductance by the core length and on how it is positioned in the bobbin. The one on the left has the same length as the one on the right but is centered in the bobbin where the one on the right has one end flush with one end. If you were to have the correct number of windings but moved the position of the core, you would alter the inductance properties. This is why I adhere so close to Steve's original design.



post #868 of 1643
Wow, Jamie that confused me, but one heck of a job. I stumbled upon this thread because my dad gave me two TIMEFRAME TF 500's. When I started reading the posts in 2009, I had no idea this thread was still frequented.
post #869 of 1643
Love dcm speaks.

Have owned tf400s for years, tw1s for months, had some 1as i had to send back due to damage by ups, now have some 3s.

After one day, while i love them, I have to admit, i think maybe the 1as were more to my liking.

Still playing with placement etc., and dont get me wrong, these are fabulous speaks, but I might be on the lookout for some 1as again after thinking i would never want any more speaks.

Dont know if they are too much speak for smallish room, need more power than my 125watt adcom amp, or just the sound of these incarnations.

hopefully i can successfully attach a pic.
LL
post #870 of 1643
I'm very pleased to have stumbled across this thread and discovered that DCM is still alive and well among so many others.

I'd like to begin with some shameless fawning and say to Mr. Hauser that you are a gifted craftsman and I eagerly anticipate the audio review on your new 7's when you get them finished. What a project!

I had the great good fortune to work in a hi-fi shop in the late 70's that was a DCM dealer where I had the opportunity to A/B via a switching console every combination of signal source, pre and power amp and speaker in the shop, all in a tuned listening room environment. After listening to the TW 1's for the first time, I picked my jaw off the floor, bought a pair and have never looked back (they absolutely burned down some very highly regarded and very expensive speakers.) Today, like me, they're getting old but still standing, and I still love 'em.

I recently made a serious score and picked up two pair of mint TW Surroundscapes (along with four BGW monoblock amps) and have a couple of questions for any of you who would care to chime in. First of all, having incorporated one pair of these into my HT (Wow!) I immediately realized I need a better center channel speaker. Having read through this thread I see that the CX 17 is well-thought of for this application. Right now on Ebay there is an orphan CX 17 (kind of rough-looking), as well an orphan CX 07 and a 16C for sale. Any and all thoughts/opinions on these or anything else would be appreciated. Also, have any of you tried on a pair of these as regular stereo speakers? Would I find enough 'improvement' over my TW 1's to warrant the effort to rig them, or should I just keep Pair #2 as spares?

Thanks in advance & it's great to be here.

Don
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