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Thread: Eld's DIY subwoofer |
    
Silver Member Username: Eld
Texas
Post Number: 193
Registered: Dec-05
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| Posted on Friday, May 25, 2007 - 10:17 am: |
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Hi guys,
It's been a while, but after having a new addition to the family and other life priorities, I finally got my subwoofer project done and integrated with my Audiences. I thought you guys might enjoy seeing the end result. The DIY path can be both rewarding and fun. The driver is an Eclipse SW8200, the amp is an eDesign LT 550, and the box internal volume is around 4.5 C.F. Qts is around 0.7
Nuck and Art nice upgrades.
Jan, take it easy on a novice DIYer.  |
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Silver Member Username: Stefanom
Vienna,
VA
United States
Post Number: 607
Registered: Apr-06
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| Posted on Friday, May 25, 2007 - 10:22 am: |
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Looks pretty sweet to me. Dare I ask how much the glass top rattles? |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 10466
Registered: May-04
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| Posted on Friday, May 25, 2007 - 10:34 am: |
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That's a pretty big box. Why so big? I assume it's a sealed enclosure with that sort of internal volume. Why sealed? Or, am I misreading this and it's a TL type? Doesn't look like quarter wave pipe. I'm not a big fan of ported enclosures other than TL's, but I find a sub with truly deep bass extension can be made to sound good using a vented enclosure, with minimal traces of ported enclosure sound and much smaller internal volume. So what choices did you make and why? Where did you get the plans or did you work them out yourself?
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Silver Member Username: Eld
Texas
Post Number: 194
Registered: Dec-05
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| Posted on Friday, May 25, 2007 - 10:49 am: |
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Hi, Stephen
Thanks for the compliment. There are no rattles that I can tell. I braced the box both at midspan and corners and it's pretty much solid. |
Gold Member Username: Arande2
Just a matte...
Missouri
Post Number: 2458
Registered: Dec-06
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| Posted on Friday, May 25, 2007 - 11:04 am: |
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I know I'd like the sound of it. Of course, it wouldn't be loud enough for me. Great job though.
By what I can see, I would infer that it sounds great and goes really deep. My guess would be it reaches 110-120dB when pushed? Just a guess. |
Silver Member Username: Eld
Texas
Post Number: 195
Registered: Dec-05
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| Posted on Friday, May 25, 2007 - 11:47 am: |
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Hi, Jan
Hope everything is going well with you.
The box is indeed a sealed enclosure, since SQ with deep extension is my main goal. Ported sub was my last choice. TL is definitely a step up. Box size was chosen based on driver published T/S parameters and WAF. In addition, it's a LMS motor from TcSound with a huge magnet, unlike XBL^2; a large internal volume is a plus in keeping the internal temperature more stable. I also mounted the amp high in the box for better cooling but at a small cost of stability. I did all the modeling and plans using Autocad and WinISD. The Mms/Bl ratio is a little higher than some of the other drivers I was looking at, but I liked the low Fs and LMS technology of this driver.
Overall, I’m pretty happy with the result. It plays clean, deep and loud.
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Gold Member Username: Nuck
Post Number: 7391
Registered: Dec-04
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| Posted on Friday, May 25, 2007 - 12:04 pm: |
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Elderion, nice work! The cabinetry looks teriffic and I admire the artwork on the grille, too!
You might consider spikes to save the carpet? That think looks HEAVY!
Thanks for sharing. |
Silver Member Username: Dmitchell
Ottawa,
Ontario
Canada
Post Number: 104
Registered: Feb-07
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| Posted on Friday, May 25, 2007 - 02:25 pm: |
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Very nice! You must have some above average wood-working skills? |
Silver Member Username: Eld
Texas
Post Number: 196
Registered: Dec-05
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| Posted on Friday, May 25, 2007 - 03:16 pm: |
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Thanks Andre
I haven't really pushed my system to the limit. No idea how loud it can go, but it's definitely loud enough for me. WinISD shows that your numbers are close.
Thanks Nuck
It was really a lot of fun cutting and staining the box. I though about matching the Audience's look, but my better half liked the end-table space saving idea. The sub is heavy. I'm guessing it's about 70 lbs. Initially, I planned for spikes, but the legs were order to match the rest of room's furniture. |
Gold Member Username: Arande2
Just a matte...
Missouri
Post Number: 2459
Registered: Dec-06
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| Posted on Friday, May 25, 2007 - 07:42 pm: |
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I used WinISD. I cheated =P lol |
Gold Member Username: Wingmanalive
A pic is worth
1000 posts!!
Post Number: 6800
Registered: Jun-06
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| Posted on Friday, May 25, 2007 - 09:07 pm: |
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Wow! Man that is really impressive. Nice addition to the room. I'd be getting some heavy duty coasters if I were you. Your drink would slide right off. |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 10470
Registered: May-04
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| Posted on Saturday, May 26, 2007 - 12:27 am: |
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I don't know anything about the amplifier. Where'd you get it and why that unit? If it ever stops raining down here so I can pull my saw out of the garage, I'm building a TL (or, as the man with the numbers prefers, a restricted terminus quarter wave resonator) with the Adire driver Tim used in Emma. I'm looking right now at the B.A.S.H. amplifiers since I need the 24dB LP filter to make the sub work well with the 3/5a's. |
Silver Member Username: Davidpa
Portland,
Oregon
US
Post Number: 469
Registered: Nov-05
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| Posted on Saturday, May 26, 2007 - 01:36 am: |
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Great job. If it sounds anywhere near as good as it looks, your in good shape!
Time well spent. |
Gold Member Username: Nuck
Post Number: 7395
Registered: Dec-04
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| Posted on Saturday, May 26, 2007 - 06:24 am: |
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Jan, what enclosure volume do you end up with for the XBR2 driver? |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 10473
Registered: May-04
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| Posted on Saturday, May 26, 2007 - 10:15 am: |
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Hell, I don't know, Nuck, it's somewhere around 7000 cubic inches. The total enclosure "volume" is not as important as the pipe's cross sectional area, pipe length, driver and port placement and the stuffing density when doing one of these quarter wave pipes. It isn't small however at 80" overall length and roughly 42 square inches of cross sectional area for the pipe. This particular pipe is based on Rick Schultz's "Omega Quarterwave Reflex" tables published in AudioXpress 10/2005. Martin King and G.L. Augspurger also work with similar designs and King has a MathCad program that predicts the results of pipe length and driver/port placements based on a relatively small number of TS parameters. You can find their work through any search engine looking for TL parameters.
The same driver is in place in the Emma and Adire prefers to use the driver in a slightly less than one cubic foot vented enclosure tuned to around 30Hz. That enclosure is in the HT room right now. Tim made the enclosure for Emma slightly smaller than one cubic foot to gaim some other advantages and the driver still performed below that number in my HT room. The XBL^2 technology seems to work well for low frequency drivers. I don't know this LMS technology but I assume it strives for the same benefits.
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Silver Member Username: Eld
Texas
Post Number: 197
Registered: Dec-05
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| Posted on Tuesday, May 29, 2007 - 09:56 am: |
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Jan,
Interesting TL project. That box is pretty big too. The Emma 6" driver is a well proven performer. What kind of stuffing material did you use?
As far as the plate amp for my sub, it's produced by Keiga for Elemental Designs. I'm hoping it is a good product based on the Keiga name and the 5 year warranty provided by Edesigns. It has (2)-4700uF-120V caps, decent for a D-amp. I'm guessing the toroidal transformer is around 600 VA based on its weight and amp rating. Some of its features are speaker line-in, LFE in, and a variable phase adjustor. Drawback is that the heat sinks are inside of the faceplate, so accommodations must be consider for cooling with sealed enclosure. |
Platinum Member Username: Jan_b_vigne
Dallas,
TX
Post Number: 10493
Registered: May-04
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| Posted on Wednesday, May 30, 2007 - 10:31 am: |
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Yes, the quarter wave pipe, like any variation of a TL, is large and that may be it's downfall in this room. The small ported enclosure I have already constructed for the HT room using the same driver does quite decent bass response for my needs. At 1 cubic foot for that enclosure and upper 20Hz response in room unless the QW pipe has significant advantages in sound quality (I do like the sound of TL bass), the saw will be coming back out to reduce the size of the new box to a more comfortable package.
I went with PolyFill for this project. According to Schultz's tables and text the choice of damping material will not affect the sound quality of the final project as much as good construction will benefit the end result (though there will always be someone who claims theirs is superior to mine due to their attention to this or that about which I "just don't get it and/or don't care enough and/or wish to spend as much") since dampening a TL/QW pipe is still somewhat subjective as to quality of bass response. "Stuffing" the QW pipe largely differs from stuffing a conventional TL by using Schultz's tables to predict the amount of stuffing material required and by strict adherence to the length of the pipe which includes damping material. Going to fiberglass rather than PolyFill reduces the pipe length less than four inches and makes for a material that is more difficult to work with. Going to AcoustiStuff, long hair wool - or whatever - significantly increases my cost for what should be a fairly simple and inexpensive project. As designed this subwoofer is meant only to reproduce the better part of the last octave beneath where the Rogers roll off, roughly 40Hz and down. I'm not trying for 15Hz response and there is no midrange that will be passed through the driver so fancy stuffing materials just don't make sense to me for this project.
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