Dallas II BLH Plan

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Teflon

Re: Dallas II BLH Plan
« Reply #60 on: 25 Oct 2010, 02:59 am »
I can't answer your questions but that's a nice looking speaker you built there  :thumb:

mp9

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Re: Dallas II BLH Plan
« Reply #61 on: 25 Oct 2010, 05:42 am »
What i remember of the Huston: www.diyaudio.com/forums/full-range/110611-fe206e-question-2.html#post1347985

Actually this was the last i remember Ron Clark (REC1), talking about in post#311 the attached file: www.diyaudio.com/forums/full-range/132363-fostex-fe103e-32.html
and post #267: www.diyaudio.com/forums/full-range/132363-fostex-fe103e-27.html

Been a long time since I came across one of his post, I hope he's OK and fly-fishing in the 'dacks or somewhere in the Hudson river valley or another of his favorite spots.

mightym

Re: Dallas II BLH Plan
« Reply #62 on: 25 Oct 2010, 11:48 am »
Squalor, nice looking build!  What driver is that?  I doesn't look like the '206...
To answer your questions, they are made of engineered wood product called "Advantech" it's used for subfloors, and is made similarly to OSB, where flakes of wood are coated with some kind of heat cured resin, and then formed into sheets under tremendous pressure and heat.  It has virtually no voids ( well it has some really tiny ones ).  I took almost 2 complete 4x8 sheets to build my 2 horns.  they will be getting an added bit of ply on the sides/top to put a bright finish on when I'm done, and paint on all other surfaces, along with a grille on the front for WAF.  The foam filling the upper voids is plain old PU expanding foam from a can, like what you would use to stop drafts around plumbing and wiring.  I used a combination of Gorilla glue, and Elmers Carpenters glue in assembly.  I like gorilla glue, it holds well, and gap fills to make up for my poor joinery.  The wires are 2 runs of 22 ga. Teflon insulated solid copper twisted into a bundle that fits in a 1/4" hole, sealed with silicone.  I ran 2 runs so that if I wanted to/needed to I could do 2 things. 1 add a super tweeter if I felt it needed it at a later date, or 2 experiment with the wiring combination and some series resistance to control the bass.  They are not installed yet, but the horns will be getting spikes to rest on.  As to the music, see my last post from yesterday regarding listening impressions. 

These are still a work in progress, I work slowly, and I hope deliberately, so that I have to go back and re-do stuff less....

mp9, thanks for the links.  I've spent hours, and hours looking at threads Ron was active in for information on these Dallas II's, since he is no longer active.  I also spent a lot of time in the archives of the Fullranger forum.  Ron posted a considerable amount of information about this design there.

John

Ps:  I went back and reread the mentioned prior post, and I failed to mention anything about the bass other than that some would be happy without a sub...I didn't mean to belittle the bass on these, quite the contrary, my audio buddy who was over with the OB's and I discussed the bass extensively, my impression is that the whole speaker is pretty well balanced, the bass is very quick, not flabby, and things like an upright acoustic bass sound like they should, while cymbals sound like cymbals too and not hisses.  I do plan to experiment with some series resistance as recomended by Ron at some point.  We talked about the bass timing, I know that some people's hearing is so attuned that they claim they can hear the 9 microsecond delay of the backwave as it is amplified and phase shifted by the back horn, but I cannot.  The bass these make rolls off somewhere in the low 50's according to Ron ( I can't measure it yet...) And I believe him.  The only thing I would like bass enhancement on would be use as the mains in a home theater, or heavy pipe organ music.  For music only, and especially the music I listen to regularly, these are quite satisfying as they are.  The folks who have built these, that I have had contact with, all seem to be satisfied that these were an excellent choice, and do not seem to be in a big hurry to replace them.  I can now understand why.  They're good!

squalor

Re: Dallas II BLH Plan
« Reply #63 on: 25 Oct 2010, 09:25 pm »
Thanx MM, I also took a long time to build mine. I had my wood cut to a flat pack like you did, using a saw board. Then a hurricane came to Gulf Shores and I had to use the big pieces to board up my windows.
I used three 5'x5' sheets of 1/2" Russian Baltic Birch. I also had to re-draw and do the math for the thinner wood. I doubled the thickness on the baffle and long internal piece by gluing two sheets together with Gorilla glue. Bad move, the glue expanded and left voids. I had to re-do them. If I had a do over, I would have used 3/4" 7-ply cabinet grade plywood from Home Depot. It's actually 23/32" or something like that so the .700" measure on the plans would work. Ron designed them so each cabinet could be done with one 4x8 sheet. I would have used only yellow carpenters glue. I did use NO fasteners. I drew the plan right on the 17.7x48 side and used a square to glue the 11.04 pieces 90* upright to the side. If I had a do-over, I would have the 11.04 and 17.7 pieces cut to width with a panel saw.
I used Cat5 network cable for wire and had the terminals at the back by the top of the braces. Others have the terminals on the side of the cabinet straight out from the compression chamber. Not as pretty but probably a better way. I did not line the outer curves with felt. I should have. I do not have any spikes or feet, it sits right on the carpet. The drivers are Fostex 206E with no modification. They look darker behind the metal grills. If I had a do-over I would have made a grill with grill cloth as I'm sure the metal colors the sound. I made the part above the baffle angled and Ron said this was a bad idea, that area was calculated into the design.
When constructing, when I had glue squeeze out I wiped it into the join. Bad idea. The area with the smear would not sand out and not accept stain. I should have let the drops dry and then remove them with a scraper or knife. I should have paid attention and aligned the grain of the wood on all visible 11.04 pieces.
The top is hinged at the back and flips up to reveal a hidden compartment. The speakers have served me well but in the back of my mind, I know they could have been better. I hope anyone planning to build these can learn from my mistakes, as they learn from your successes.
Joe

mightym

Re: Dallas II BLH Plan
« Reply #64 on: 22 Nov 2010, 03:15 am »
I've been busy/lazy lately.  Busy at the new job all week, Wore out lazy on the weekends.  I did get out and work some this weekend.   I'm looking forward to the Thanksgiving break to get some more done.  I've pulled the drivers, and begun the process I use to finish the OSB, which consists of the application of the sekrit sauce, to as they say in the boat building world " Fair " the surfaces.  Some of them will be getting a custom mixed paint, and the top/sides will get a layer of thin ply with some nice veneer.  I'll be constructing a full length frame for some grille cloth to satisfy the WAF requirements.  No pictures yet, I keep forgetting to take the phone out to the shop 'cause it searches for a signal 'till it runs it's battery down and starts to annoy me with it's insistent little screeches to indicate that it's out of juice.  Hopefully I'll get the pics updated this week when I get back to work in the shop.

John

squalor

Re: Dallas II BLH Plan
« Reply #65 on: 24 Nov 2011, 12:12 pm »
Any updates John ? Are you powering these with the KT88SET ? My amp died in a storm so I'm back in the game looking for a upgrade/replacement.

planet10

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Re: Dallas II BLH Plan
« Reply #66 on: 25 Nov 2011, 07:16 am »
Been a long time since I came across one of his post, I hope he's OK and fly-fishing in the 'dacks or somewhere in the Hudson river valley or another of his favorite spots.

Scottmoose has had email contact in the last couple months.

dave

planet10

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Re: Dallas II BLH Plan
« Reply #67 on: 25 Nov 2011, 07:19 am »
I would have used 3/4" 7-ply cabinet grade plywood from Home Depot. It's actually 23/32" or something like that

18mm. Metric sheets confabulated into imperial.

dave

mightym

Re: Dallas II BLH Plan
« Reply #68 on: 26 Nov 2011, 11:42 pm »
Squalor,

I have to ashamedly admit I've yet to finish the cab's for my Dallas II's.  I was afraid that this would be the result when I went back to over the road trucking last year, instead of the local work I'd been doing.  I had no choice at the time, gotta feed the family, pay the bills, etc.  To answer the other question, I have/use an 8W KT-88 SET for my system.  I love it.

I'm glad to hear that SM has had contact with RC, Dave.  I was afraid he had moved on.

I'm going to try to take some time off around Christmas, and get out into the shop to finish several languishing projects.

I'll try to update then.

John

I managed to restore an old Dell my sister destroyed, and now have a computer to take on the road.  It's nice to be able to catch up a little more often.  Mickey "D"s free wifi is a great source for the web for the traveller, but bad for my waistline....

squalor

Re: Dallas II BLH Plan
« Reply #69 on: 28 Nov 2011, 01:05 am »
Life is what happens while your busy making plans. Isn't that what John Lennon said ?
McDonalds is my favorite mexican restaurant, that southwest salad they have is tasty with a little ranch mixed in to cool the sw dressing.

Quote
I'm glad to hear that SM has had contact with RC, Dave.  I was afraid he had moved on.
That's great to hear ! Thanx planet10 for updating us. Maybe that ole Texas Bullfrog will catch the bug again and send it to Houston.

After I get my amp situation sorted out I was thinking about turning my attention to speakers again. Houston, though an unfinished design, would be interesting to test. Maybe another Dallas II but with 208 sigma and a ribbon, bi-amped with Pass F1 & Aleph clones (if I hit the lottery). Also, wondering if planet10 might hot-rod my FE206 with his latest magic.

Till then I'll keep my hobby in it's place and concentrate on the important things, trying to do the right thing and loving the people god sends my way.

planet10

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Re: Dallas II BLH Plan
« Reply #70 on: 28 Nov 2011, 02:30 am »
Quote
Also, wondering if planet10 might hot-rod my FE206 with his latest magic.

I'm pretty sure he can do that

dave

Maxdd_nj

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Re: Dallas II BLH Plan
« Reply #71 on: 28 Nov 2011, 03:00 am »
Anyone build or listen to the RCA-Fan backloaded K-horn? It was designed by Bill Woods of AH! and appears to be a quicker build (less cuts?). You got to love the look of that K-horn slot.
http://www.acoustichorn.com/tech/k-horn/

I have a pair of FE206 and my dilemma has been Dallas II or Bill Wood's design.


chrisby

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Re: Dallas II BLH Plan
« Reply #72 on: 28 Nov 2011, 05:59 pm »
Anyone build or listen to the RCA-Fan backloaded K-horn? It was designed by Bill Woods of AH! and appears to be a quicker build (less cuts?). You got to love the look of that K-horn slot.
http://www.acoustichorn.com/tech/k-horn/

I have a pair of FE206 and my dilemma has been Dallas II or Bill Wood's design.



gotta build both I guess  :thumb:


Bill's design does look a bit simpler