AudioCircle
Industry Circles => GR Research => Topic started by: Danny Richie on 19 Apr 2008, 12:24 am
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Here's a good one. This is a 1.5 cubic foot sealed box for a single SW-12-04 Direct Servo sub.
(http://www.gr-research.com/images/solid1.jpg)
This is the inner box. It is built from 3/8" thick MDF on four sides.
(http://www.gr-research.com/images/solid2.jpg)
The braces are 2.875" apart and are made from 3/4" MDF. The woofer mounts in the front (as shown) and the plate amp will mount on the panel on the rear.
(http://www.gr-research.com/images/solid3.jpg)
Next some 3/4" wide and 3/8" thick MDF strips are cut and laid in line with the braces below.
(http://www.gr-research.com/images/solid4.jpg)
When this is set into the outer box it leaves a 3/8" thick space between the walls.
(http://www.gr-research.com/images/solid5.jpg)
Next five sides of the outer box is built around it.
(http://www.gr-research.com/images/solid6.jpg)
Additional 3/4" thick pieces cover the front (where the woofer mounts) and the back panel where the amp will mount.
(http://www.gr-research.com/images/solid7.jpg)
Then comes the fun part, pouring in the sand. Shaking it, rocking it, and beating the sides with a rubber mallet insured that the sand was forced in as tight as possible and as much as it could hold.
(http://www.gr-research.com/images/solid8.jpg)
Then the last panel is glued on sealing it up.
(http://www.gr-research.com/images/solid9.jpg)
So far, so good. It is a rock solid box.
Next I cut the amp hole in the back.
I also plan to seal the back of the amp from the inner air space.
More to come...
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I Love It! Great pictures.
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Wow, I hope that is a pallet that the sub is sitting on because you're going to need a fork lift to move it. :thumb:
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Really nice inspired design. Is this a personal project?
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Really nice inspired design. Is this a personal project?
I guess so. I mean, I have all of these really bad to the bone Direct Servo subs in stock and the amps are now in stock as well. So I figured I better get a few of them built out so that I have them to demo.
When I am through with it I will also make the plans for it and the non-sand filled version available for those that would like to build this type of box.
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:lol: You had me going there with that 1st picture Danny with those thick center ribplates being surrounded by such thin side walls. It didn't make a lick of sense to me but I should have known there would be much more to it. :oops: I like that design a lot,,, makes me wish I needed another sub. :drool:
And thanks for sharing your design with pictures,,, very nicely done indeed! :thumb:
Cheers,
Robin
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:dance:
Nice work Danny
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Wow, I hope that is a pallet that the sub is sitting on because you're going to need a fork lift to move it. :thumb:
A perfect compliment to the 350 lbm big blue amp! :lol:
Nice work, Danny!
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Amps :thumb:
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You got in Marbles.
The weight isn't too bad. The total amount of sand was a little over 10 pounds. I even sifted out the small rocks. :D
It took some extra time to build it this way, but it was pretty easy.
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Excellent enclosure Danny :thumb:
I did something very similar with a custom pair of large stand mount speakers I built for a customer about 9 years ago. Last I heard he still had them and still lovin 'em.
It does look a bit time consuming but well worth it in the end. For a subwoofer, I can't imagine a better way to go.
I have 4 50 pound bags of sand laying around. Now I know what at least one bag will be used for :wink:
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danny,
could you possibly give the dimensions and cutouts?
thanks,
drmike
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Nice approach, guess folks better invest in a hand dolly to cart those about the house!
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could you possibly give the dimensions and cutouts?
I am going to draw the whole thing out.
Nice approach, guess folks better invest in a hand dolly to cart those about the house!
I weighed it today. The empty enclosure weight was 66 pounds.
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Has anyone completed one of these subs yet? Post some pic's and let us know how these bad boys sound. I'm still plugging away on Rob's 4 boxes.
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Christof,
Sorry this won't be totally satisfying but here goes, sorry no pics. I have a Rythmik DS12-04 sub and last month switched the stock aluminum cone driver for a GR 12-04 paper cone driver. Made a smaller 1.5cf cab. No sand damping but 4 of 6 walls are 1.5" mdf/BB (incld. woofer and amp baffles), BB bracing. Am using original Rythmik amp, not new ones for GR drivers.
At first it seemed a bit softer sounding but broke in to be nice and clear and dynamic. I didn't keep the alum. driver for comparisons tho (sold it too soon) so can only go by memory.
The GR driver does seem more open and lively. The lighter cone does however have less power handling as I bottomed it playing Battlestar galactica movie, just a light click tho.
I'm into Rythmik/GR subs now, and would ultimately like 3 per side OB drivers, or 2 per side 8 ohm in sealed, but will probly go with another 4 ohm for stereo (room and $ thing).
Rythmik subs are the best I've had, tight and deep. Hope you get yours done soon.
Don
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dimensions and cutouts?
thanks,
drmike
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What is the minimum size for the side with the driver cutout?...how much wood around the driver is needed to support it, and no acoustic problems?
How would 1" MDF work, internally braced, and lined with No-Rez? 85% of the effectiveness of the sand box?...50%?...95%?
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The diameter of the hole needed to counter sink the driver is 12 and 9/16 inches. The through hole is 11"
I used two layers of 3/4" MDF for the front baffle. Counter sinking it removed 5/8" of depth leaving 7/8" thick material beneath it.
A well braced box lined with No Rez would still be very effective. I'll have to build one out to compare it to the sand lined box.
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Hey Danny, could you make one of the enclosure drawings for a sealed enclosure with 2 gr/rythmik 12-08 subs in separate 1.6 cu.ft airspaces?
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Yeah, give me just a little bit of time and I'll have the drawings done.
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ok,sorry for the bad timing
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It wasn't a bad time for you to ask me about it. I need to get some of those drawings done. I plan to do a couple of different ones, and one with the sand filled area option. I just need more hours in the day.
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If i knew corporate america would not screw with it ,and i had a winning tax free lottery ticket, i'd love a 48hr day, :thumb:
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Danny - Have you ever tried sand filling an LS? Would it make much difference?
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Danny - Have you ever tried sand filling an LS? Would it make much difference?
I have not. I am sure it would make some difference but so does just lining it with No Rez. I wonder how much overkill is too much overkill? It is also important on these to keep the baffle width as narrow as possible, so it would have to be done in such a way as to not increase baffle width.
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hi danny, not trying to rush you, just posting this as a reminder that you said the drawings for the design of the subwoofer box ,for the pair of 8 ohm version of the servo sub, with dual 1.6 cubic foot sealed chambers would be available and posted in about a month or so.
oh and to answer your query a dear friend of mine said that overkill is the least you can do :D :thumb:
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I am working on them right now.
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Single woofer box plans are up: http://www.gr-research.com/pdf/singleservo.pdf
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Plans are now up for the Sand Box: http://www.gr-research.com/pdf/sandbox.pdf
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!
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Plans are now up for the Sand Box: http://www.gr-research.com/pdf/sandbox.pdf
Great! Thanks for taking the time to draw them up.
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i thought about it while i was at work ,and i realise i was abit selfish innot trusting danny to post the drawings for the 2 driver version. my apaologies danny . i did notice 1 thing danny, in the original subwoofer topic. you said that these drivers would be able to fit in an 11 inch cutout. but the cutout in the drawings you posted arec over 12 inches.?
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that is the face plate recess size. if you cut a HOLE that size it would fall right through :P
afaik the cutout is exactly 11"
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thanks werticus, that makes a lot more sense. i took a 2nd look and you were right. i need a vacation pretty bad :green:
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HI Danny, any update on the drawings for the 2 subwwofer cabinet?
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I might get a chance to get back on doing drawings later today.
If you can put two and two together you can pretty much get it from this one: http://www.gr-research.com/pdf/singleservo.pdf
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Hi Danny
Is the title of this post true?
so if i want to do OB from 100hz and higher
i will have better bass ( 100hz and lower) than the OB bass with two of yr 16ohm servo drivers in their own OB?
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My thoughts are that if you are going to build box for the best sounding subs available then you need to make it really solid and nonresonant.
OB subs are a different animal all together and have a clean transparent quality that a boxed sub just doesn't do. The OB servo subs hit hard but don't load the room. It is clean and tight with great extension but doesn't knock anything off the walls. It truly is something special.
If you are already using an open baffle speaker then this is the bottom end you've been waiting for.
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Danny,
How did you "seal the back of the amp from the inner air space"? It seams like it would be good to isolate the inner air with a nice solid dead no-rezed wall, but then maybe that would be overkill.
Typed on my new iPhone
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The amp has a gasket on it that will seal it. I did however, put a small enclosure around mine to further seal it. I will have the flat wall of the amp enclosure covered with No Rez as well.
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Do you line the entire box in No-Rez? If so, how many sheets does it require?
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Do you line the entire box in No-Rez? If so, how many sheets does it require?
I did. You can cover the 4 sides between the braces and just use 1 sheet. If you want to cover any sub enclosure covering the plate amp then you'll need a second sheet.
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Danny-
Wondering if you could comment on the sonic differences between the SandBox and the standard sealed enclosure. The SandBox looks to be a great design, just wondering if you had thoughts after comparison listening.
Also, was wondering if you could extrapolate on the measures you took to seal the amp from the air space. I'm assuming you built a box around the amp, with the wires passing through to woofer. Any info or pics would be greatly appreciated.
Patrick
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are the wood screws that come with the sub driver sufficient to support the driver or would I be better off using T-bolts (I think that is what they are called.
Thanks
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The wood screws will work fine.
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Also, was wondering if you could extrapolate on the measures you took to seal the amp from the air space. I'm assuming you built a box around the amp, with the wires passing through to woofer. Any info or pics would be greatly appreciated.
Yeah, I've been wondering about this myself, and will soon have to make some sort of hole to pass the wires. I've thought of a little door with some gasket with the wires being squished in the gasket, or just drilling a hole, and sealing it with some good caulk (which will be annoying should I need to remove the amp or speaker). Or, just put a little hole and leave it open. The back wall to which the amp is mounted, is sealed too...
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well binding posts would seem appropriate...
-Tony
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well binding posts would seem appropriate...
Seem appropriate, but I'm not going there, I'll likely just use some big stretch caulk to fill a small passthrough hole.
As for the binding posts. I have a love hate relationship with them in general. If I had my way -- and perhaps in a future speaker project I'll do it this way -- I would simply run the internal wires out of the cabinet, and direct solder the speaker wires, that eliminates one solder joints and one compression joint in the signal path. Not to mention the money you save on the binding posts.
Sure, you're stuck with your chosen speaker wires, but you can always re-solder it later on.....hmmmm. maybe I WILL do this on my Neo-2-Xs....
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... or maybe no box and a lot of cone area! :surrender:
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or maybe no box and a lot of cone area!
O.B. is the future! aa
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Any updates on this sub box, did it perform as expected? In your opinion, was it worth the extra effort over a standard braced cabinet?
If so, what kind of sand did you use ("sharp" or "round") and is there any concern that the sand would settle over time and "shake" in the box?
I need to build two boxes and am interested in this design.
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if you still have choice
why not choose for an OB design for most open resonance free bass?
no sand, except on the beach ;)
easy enclosure and so on
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Not interested in OB, plus the drivers I plan to use at first I already have, Rythmik non-servos, which are recommended for a sealed enclosure.
Later will upgrade to the servo sealed models.
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The sand box worked out great and was actually pretty easy to build.
I used play sand from Lowe's and I sifted out the larger pieces and used only the finer sand.
A little rocking around and hitting the sides with a rubber mallet allowed it to be packed in pretty well.
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Thanks, glad to hear it worked out.
Since the 2 cu.ft. sealed box is an easy design, figured I can add a little effort to the box construction.
Here's a question maybe either you or Brian Ding can help with. Instead of going the sand route, if I were to build a single wall cabinet, and line all the internal walls with 2" Owen Corning 703 fiberglass instead of polyfil (excluding any bracing), would the driver "see" a larger enclosure, and if so, what internal area should I start with.
I'm thinking with the above scenario, I could still build a double wall cabinet (without the air space in between the two walls), and end up with an external size similar to a single wall box.
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If I weren't going the sand lined route then above and beyond a thicker wall I would use a lot of bracing. It is better to break up any flat panel areas so that it minimizes any chance of a resonance.
Any damping material used to slow down the air flow in a box will make the woofer act as if it is in a larger box.
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Any damping material used to slow down the air flow in a box will make the woofer act as if it is in a larger box.
Yes that's what I was thinking. So I could build a box with an internal area of say 1.75 cu. ft., add the fiberglass, and the driver "sees" an internal of 2 cu.ft. Which would then equal a smaller outside box dimension. Of course I would still do the proper bracing on the inside.
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FWIW...I can't say that I know all the ins and outs of all the subwoofers available these days. but, I do know that most conveniently available subs have thin walls, and sound like [insert favorite rude word here], as demonstrated by the way the sound in the store (or in some [again...]'s cars).
I also know that the subs I might want to buy have slightly more solid walls, are overpriced, and are not in my budget.
BUT, I know that my sandbox is beyond what I had imagined, so, I'm a happy camper.
My only error is that I didn't get a long enough sub wire (soon to be corrected).
Another thing... If you put 50+ pounds of sand into your sub...
verily thine subwoofer will much weight now have.
it's a minor detail
(oh, yeah, you can hear all the minor details too)
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How about a variation of the sand box idea, a sort of in-between the sand and non-sand versions.
One of my "diy project to be" is building one of Bob Brines TL single driver speakers (LT-2000). He sells the plans, which I have purchased. In it, and on his web site, he states that he uses Hardi-Backer board to line the inner enclosure, before attaching the damping insulation.
Obviously one would have to adjust the internal volume measurements to account for the extra lining.
Good idea?
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Good idea?
I can't see that it would hurt.
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How about a variation of the sand box idea, a sort of in-between the sand and non-sand versions.
One of my "diy project to be" is building one of Bob Brines TL single driver speakers (LT-2000). He sells the plans, which I have purchased. In it, and on his web site, he states that he uses Hardi-Backer board to line the inner enclosure, before attaching the damping insulation.
Obviously one would have to adjust the internal volume measurements to account for the extra lining.
Good idea?
I'd built ft1600mkii using the plans bought from bob brines. The resulting cabinet was extremely inert. I'm sure that if you build the servo sub using this technique will work out just great!
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How about a variation of the sand box idea, a sort of in-between the sand and non-sand versions.
One of my "diy project to be" is building one of Bob Brines TL single driver speakers (LT-2000). He sells the plans, which I have purchased. In it, and on his web site, he states that he uses Hardi-Backer board to line the inner enclosure, before attaching the damping insulation.
Obviously one would have to adjust the internal volume measurements to account for the extra lining.
Good idea?
I'd built ft1600mkii using the plans bought from bob brines. The resulting cabinet was extremely inert. I'm sure that if you build the servo sub using this technique will work out just great!
Good news. How did you cut the Hardi board stuff? I imagine it was a mess to do so. Been there/done that.
I just picked up a Husky wet saw from Home Depot for a 800 sq. ft. paver job I'm trying to get done (with no help from the weather :) ) I could probably cut rough pieces with a circular saw w/masonry blade, then use the wet saw for final precision cuts.
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I didn't go with precision cuts for i don't have the tools needed. I used a knife to make marking on the hardibacker, and then used a hammer to break it. Worked okay :)
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Just cut the Hardibacker with a circular saw. Use a clamped board for a guide. Since, I presume, you won't be making numerous cuts, the saw bearings won't be damaged by the dust.
-Roy
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Well reading this and speaking to Danny convinced me to do this exact sub.
Its going into a smallish audio only room so it appears we should be good to go very soon.
Jack
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I did not do the outer layer on mine, but otherwise the construction is similar. I'm about 250lbs and was able to jump up and down on it with no flex.
(http://i25.photobucket.com/albums/c92/iron_forge/sub_1.jpg)
This is the GR-Research SW-12 subwoofer with the PR. I had to cut a small notch for the plate amp to fit in all the way.
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The amp has a gasket on it that will seal it. I did however, put a small enclosure around mine to further seal it. I will have the flat wall of the amp enclosure covered with No Rez as well.
Do you happen to have a picture of this?
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Do you happen to have a picture of this?
I do not.
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I do not.
Would it work to inset the amp slightly into only the outer layer of MDF and the use some rope caulk as a seal?
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I'm going to build two subs, one of Danny's servo subs and another . I plan to line inside of boxes with a 3/8"-1/2" layer of a sound deadening material, used to deaden car body panels (called eDead made by Elemental design) mixed with lead shot with No-Rez over that, Here is pics of test samples I did. Sides will be 1 1/4" MDF the back will be 1 1/4" and 3/4" MDF and the front baffle will be 1 1/4" MDf sandwiched between 2 -3/4" MDF pieces with some kind of deadening layers, maybe eDead and vinyl floor tile on both sides and edges of the 1 1/4" MDF. my question is will it be a problem applying the No-Rez over this layer as it is not that smooth. Here is pics of test samples I did.
(http://)
(http://)
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Would it work to inset the amp slightly into only the outer layer of MDF and the use some rope caulk as a seal?
It has a good gasket on it already and seals fine.
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Danny,
I was planning on building the Rythmik Audio DS1200 CI subs. Recently I found this thread. In what ways would your Servo Sub kit 2 with the sandbox cabinet be superior? Looks to me to be a better sub and a better value. Thanks.
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Danny,
I was planning on building the Rythmik Audio DS1200 CI subs. Recently I found this thread. In what ways would your Servo Sub kit 2 with the sandbox cabinet be superior? Looks to me to be a better sub and a better value. Thanks.
Those woofers put quite a bit of force on the cabinet walls. The more solid and less resonant you can make them then the better they will sound.
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I'm going to build two subs, one of Danny's servo subs and another . I plan to line inside of boxes with a 3/8"-1/2" layer of a sound deadening material, used to deaden car body panels (called eDead made by Elemental design) mixed with lead shot with No-Rez over that, Here is pics of test samples I did. Sides will be 1 1/4" MDF the back will be 1 1/4" and 3/4" MDF and the front baffle will be 1 1/4" MDf sandwiched between 2 -3/4" MDF pieces with some kind of deadening layers, maybe eDead and vinyl floor tile on both sides and edges of the 1 1/4" MDF. my question is will it be a problem applying the No-Rez over this layer as it is not that smooth. Here is pics of test samples I did.
(http://)
Mike no need for such construction it is overkill. Just use Danny's plans with no-rez and be a happy camper.
charles
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Charles, I actually didn't do that exact design and didn't use it with one of Danny's subs. The box I built for my seal GR sub used the sand box design but with lead shot instead of sand, one very dead box.
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Did any of these make it out into the wild?
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Did any of these make it out into the wild?
I've had a lot of customers build the sand box.
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I have one. Beast to move but I like it.
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Did any of these make it out into the wild?
I have one in the basement. I named it which is unusual for me. Herniabuster. Has nice ring to it, eh?
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For HT use, would it be best to:
A: Use 2 x single sealed subs
B: Put both subs in the same enclosure (still sealed)
In scenario A, could I use the sw12-08 or sw12-16 and only use 1 plate amp to power both?
Looking forward to hearing your input.
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Best for home theater would be a sealed box sub in each corner of the room.
And two is always better than one.
The SW-12-08FR and SW-12-16FR are for open baffle applications.
For HT use, would it be best to:
A: Use 2 x single sealed subs
B: Put both subs in the same enclosure (still sealed)
In scenario A, could I use the sw12-08 or sw12-16 and only use 1 plate amp to power both?
Looking forward to hearing your input.
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I built these with sandboxes top and bottom. Real back breakers but very inert.
(https://www.audiocircle.com/image.php?id=201817)
(https://www.audiocircle.com/image.php?id=201814)
(https://www.audiocircle.com/image.php?id=201815)
(https://www.audiocircle.com/image.php?id=201816)
(https://www.audiocircle.com/image.php?id=201818)
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My Rythmik F15HP that I am building are going to be braced in several directions and I am going to use No-rez on the enclosures. I went with the 2-15", since 2-12" servos would not be enough to pressurize my space. My use is for HT. They are already going to be a beast to move, and extra sand weight would have made them even worse.
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I built these with sandboxes top and bottom. Real back breakers but very inert.
These look awesome!
You're gonna have to tell us more about these speakers. Got a link or something?
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Thanks Early Bird, these were the last pair of speakers I built before I retired. So I was doubly happy when they were finished.
They were built for a good friend whose domestic situation wasn’t conducive to OB. So he designed this kind of hybrid OB.
As discussed the top and bottom drivers are Danny’s 12” servo woofers in sealed sandboxes. The mid is a 12” Beyma. The AMT is the 500 Hz version of the AMT you have in your cast HA Obsessions so you should be pretty familiar with how those sound. The crossover is a simple series crossover.
Here’s a pic that shows the drivers a little better. The crossovers went in the space above the plate amp.
(https://www.audiocircle.com/image.php?id=201868)
They sound very good but aren’t for everyone because of their size.
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Woodsage, very nice. Interesting design and what looks to be great execution of it. These babies make a STATEMENT!
At first glance, it looks like they might be modular, but as I look closer, I'm thinkin' not. If redesigned some, do you think they could be?
I have to admit I love the idea of big ass, self contained design, but the handling of same is increasingly a concern. None of us getting younger, eh?
If I can pry, (and if not, I understand), what was the business you retired from? Speakers only, all manor of woodworking? I guess I'm curious because as I look at my own "retirement", more shop time is attractive to me. I have an acquaintance though, that sold his woodworking business and has no real desire to pursue it as a hobby. To each his own, I suppose.
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Woodsage. Is. The. MAN! That my friends is how it is done. When your work looks that good next to a Eames Lounge Chair and ottoman you are doing something very very right.
Also kudos to whoever first uttered the words "12" midrange with large AMT in open back configuration".
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Sweet. Would love to hear them.
charles
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As discussed the top and bottom drivers are Danny’s 12” servo woofers in sealed sandboxes. The mid is a 12” Beyma. The AMT is the 500 Hz version of the AMT you have in your cast HA Obsessions so you should be pretty familiar with how those sound. The crossover is a simple series crossover.
OK, they're quite similar in driver configuration to my speakers with two exceptions -- I have the AMT 700 and an 8" Beyma vs. your AMT 500 and 12" Beyma.
I have no validation for this, but I would imagine woofers up top and on the bottom would sound bad ass.
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Thank you for the compliments.
Peter J:
You're right, we're not getting any younger and these are quite heavy. I could barely tip them upright by myself once they were completed. I added sand at the back of the sub boxes as well.
These could have been built modularly but wouldn't have quite had the same seamless look. The bass boxes, front baffle and short baffle returns were all glued up as one unit. The plate amp/crossover box was a separate unit and was slid in and screwed at the top and bottom. It provides most of the rigidity of the structure. I put some angle block reinforcement at the baffle returns to strengthen them up a bit. Here's a couple pics to clarify.
(https://www.audiocircle.com/image.php?id=201881)
(https://www.audiocircle.com/image.php?id=201883)
(https://www.audiocircle.com/image.php?id=201884)
(https://www.audiocircle.com/image.php?id=201882)
I retired after 40 years in the commercial furniture manufacturing business. And I have been building speakers for people since 1985 (I started building furniture in 1978). So I'm like your buddy, no more shop time for me! Sometimes I miss the creativity but not all the other stuff that went with it and I much prefer being retired with 10 toes in the sand.
Norman Taylor:
Thank you, my buddy has good taste in furniture. The speaker design was definitely a form follows function kind of thing; I had to translate what he wanted into something that looked good and worked. But they are basically huge boxes.
Early Bird:
Not sure what Beyma Darrel used but I'm sure they sound somewhat similar. The bass is very good and having the second bass driver up high loads the room nicely. My buddy couldn't get Danny's H-Frames to work in his room.
Mike
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Are there any other pictures or links to build threads or completed sand box enclosures?
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Check out Peter J's build. His work is excellent.
http://www.audiocircle.com/index.php?topic=84765.0