AudioCircle
Industry Circles => GR Research => Topic started by: Danny Richie on 7 May 2004, 08:09 pm
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Yea I am finally having a sub-woofer made.
Actually it can be used for more than just a sub-woofer. It plays smoothly to 500Hz.
I had several objectives for this design.
As a sub-woofer I wanted low end extension with a -3db close to 20Hz.
I also wanted to do it with a relatively small box.
The main focus was to be on sound quality not quantity.
It also needed to have a nice smooth response up to about 500Hz so that it can be used in three way designs.
To get the low end extension the box has to either be ported or used with a passive radiator. Since the ports will be huge to tune a small box to a low Fs the solution was a matching PR. So they were designed together to be used together.
(http://www.gr-research.com/images/wpr1.jpg)
(http://www.gr-research.com/images/wpr2.jpg)
(http://www.gr-research.com/images/wpr3.jpg)
Since sound quality was high on the list a treated paper cone material was chosen as well as a dust cap made from the same material.
They both use the same cast aluminum frame.
A large 1.5" rolled surround was used to minimize any cone flex as the limit of the X-max is approached. This will reduced distortion that occurs from cone flexing.
I am not a big believer in playing woofers to levels that force really high X-max's. Long exertions equals high distortion.
If you want to move a lot of air and you want it to sound good then I recommend using more woofers.
Here are the specs and the tuning of the box according to Bass Box software. Adding a little bit of mass to the PR in the test box I was able to confirm the tuning with an impedance sweep.
The final product (PR) will have a bolt running through it that will allow for mass to be added as per washers and screws.
Laudspeaker Parameters
-General Information-
Company: GR Research
Model: 12 inch
Note/SN:
-Mechanical Parameters –
Fs = 20.5 hertz
Qms = 4.85
Vas = 3.56 cu.ft or 101 liters
Cms = 0.057 in/Ib
Mms = 5.964 oz or 169.1 grams
Rms = 9.843 Ibs/sec
Xmax = 16 mm
Sd = 72.5 sq.in
Dia = 9.6 in
-Electrical Parameters-
Qes = 0.440
Re = 6.7 ohms
Le = 5.16 mH
Z = 8.0 ohms
BL = 18.5 N/A
Pe = 200 watts
– Combination Parameters –
Qts = 0.40
qo = 0.201%
Sens = 87.03 dB (2.83 V)
--Multiple Drivers-
Number= 1
Single
Wiring: single
Single Driver Passive Radiator Box Parameters
Vb = 2.400 cu.ft
Vap = 6.000 cu.ft
Fp = 12.5 hertz
F3 = 20.8 hertz
Fill = normal
Oh yea! I need to think of a name and or model number for these things. Any good ideas.
There is currently a small run of 200 woofers and 200 PR's being built, just to see how they go first.
I also plan on using these in two three-way kits in our A/V series. Looks like lots of fun ahead....
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The "Delta" it will "change" how you feel about subs!
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How about: GRowLLLLLLL :evil:
Is this a powered sub?
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Danny,
Have you thought of doing a line array of the subs? Active, PR, Active, PR, Active PR? That would be wicked cool to have a stack next to and/or slightly behind the Alphas :D. I'm sure you could get the extension you're looking for with minimal distortion and a bad ass look.
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Danny: keeping with the latin.
How about:
inferne : meaning on the lower side, below.
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i tink "gr-research rumble" has a nice ring to it... of course, there's always "danny's inferno", if ya wanna keep it on the latin side! :wink:
doug s.
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klh that sounds really kick ass. I'll sell you everything you need to build a set. :mrgreen:
inferne? How is it pronouned?
Brad, didn't you come up with the name for the Diluceo?
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You already have the Alphas!
Now the Omega completes it.
Jeff
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I vote for the "Omega"...
If you make it an array, not only will it complete the system, but it will be the last subwoofer anyone will ever need (or want) :!:
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SUBTERRA :evil:
a subwoofer is not subtle, the name should be agressive
just my 2 cents
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GR-umble
GR-owler
GR-oundSwell
Name and effect 8)
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Danny: yes I did, and I sure wish you would have had these subs last year as I already spent my millions on my 2 RELS! How are these going to integrate with the Diluceos? From the description, it sounds like you are going after the Strata III sound vs. volume solution. With 2 subs, the Diluceos sound pretty good, and really eliminated some midbass haze that existed with a single. Good luck on the launch! Oh, and by the way, what do think the price range will be?
Brad
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Ah yes, the price.
Well you know me. I like to buy large volumes to get good prices and then pass that on to my customers.
I am thinking starting those woofers out at $99.50 each and the PR's at $44.50 each.
How's that?
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good deal-
now that i have a dedicated 2ch room i have to replace my vmps large in the ht setup-i do like pr based systems :mrgreen:
the GRanite-rock solid and natural bass from a foundation of excellence
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Why do you have to replace the Larger?
Just curious...
George
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larger is in the 2ch set up-
2pr of these for 300$ and some diy boxes :mrgreen:
if i liked them better for music i could move the large back to ht duty.
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I had them made as 8 ohm woofers too so if one chooses they can run a pair of them with only one plate amp.
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Do you have any plans in the works for DIY enclosures or drawings? I think this would be a fun project to make one of these sub's. What approx box size are we looking at for these drivers?
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Do you have any plans in the works for DIY enclosures or drawings?
Sure.
What approx box size are we looking at for these drivers?
See the first post.
They hit a -3db of 20Hz in only 2.6 cubic feet with this PR.
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how about doin' up a wersion w/two active drivers per box...
doug s.
Do you have any plans in the works for DIY enclosures or drawings?
Sure.
What approx box size are we looking at for these drivers?
See the first post.
They hit a -3db of 20Hz in only 2.6 cubic feet with this PR.
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Should be dirt simple to turn a box plan for one driver and pas. rad. into two driver and two pas. rad.
Should just need to make one of the dimensions twice as and probably add a window brace in the middle -pretty much as if you just glued two single driver boxes together.
Along these same lines for say a tower of 4 of these bad boys.... or two towers to be nice and symetrical. hehe
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i'd be interested in keeping only one passive w/two actives...
doug s.
Should be dirt simple to turn a box plan for one driver and pas. rad. into two driver and two pas. rad.
Should just need to make one of the dimensions twice as and probably add a window brace in the middle -pretty much as if you just glued two single driver boxes together.
Along these same lines for say a tower of 4 of these bad boys.... or two towers to be nice and symetrical. hehe
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Sorry if I missed it, but is there a price announced yet?
I'd like to buy a couple to mate with my DIY line arrays.
Danny, would you recommend against attaching the 150lbs each line arrays on top of the subs?
Would that be a bad way to go about it?
Thanks,
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XW12 - High Excursion SQ Bass Driver
XR12 - High Excursion Passive Radiator
The "BassTopia" High Fidelity Bass System BT12
w00t.
As for two actives with one passive, that's a bad idea. There always needs to be twice as much volume displacement from the passive radiators as there is from the active driver.
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...As for two actives with one passive, that's a bad idea. There always needs to be twice as much volume displacement from the passive radiators as there is from the active driver.
then how come my vmps larger subwoofers sound so phenomenal, w/a 12" & 15" active, & one slot-loaded 15" passive?
doug s.
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"-As for two actives with one passive, that's a bad idea.-"
I agree and really... why the desire not to have two pas. rads.? To save $50 and a bit of router work on the cabinet?
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"-As for two actives with one passive, that's a bad idea.-"
I agree and really... why the desire not to have two pas. rads.? To save $50 and a bit of router work on the cabinet?
i disagree, & i would prefer a potentially smaller cabinet, w/use of two active & one passive driver. it's a size thing - if i were not concerned w/size, i'd yust stick w/the vmps larger subs. which are big enuff as it is, w/only one passive radiator...
ymmv,
doug s.
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because every monkey knows -you should stay up in your funken tree
Nice quote. 8)
Actually, I just has the DMB "Live at Folsom Field" in the DVD player and played "Big Eyed Fish" - such a great song.
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i'd be interested in keeping only one passive w/two actives...
Hi Doug,
One PR would not be enough in this case for two woofers.
That would be a little like making the port to small.
Sorry if I missed it, but is there a price announced yet?
I am thinking starting those woofers out at $99.50 each and the PR's at $44.50 each.
Danny, would you recommend against attaching the 150lbs each line arrays on top of the subs?
The best place for your subs is not necessarily the best place for the main speakers or vice versa.
Keep them separate and leave yourself some versatility.
As for two actives with one passive, that's a bad idea. There always needs to be twice as much volume displacement from the passive radiators as there is from the active driver.
Yep, something like that.
The X-max on the PR is pretty huge and only limited by the suspension which uses an inch and a half rolled surround.
then how come my vmps larger subwoofers sound so phenomenal, w/a 12" & 15" active, & one slot-loaded 15" passive?
A 12" and a 15" in the same box and/or air space? really?
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From this picture:
(http://www.vmpseurope.com/pics/sublarg.jpg)
it looks like the 15" active and 15" PR could be separated from the airspace of the 12". Someone will have to ask Big B, or someone who has put this together in kit form.
p
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nothing between the 12 and 15-
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I am thinking starting those woofers out at $99.50 each and the PR's at $44.50 each.
NIIIIICE! :D
I was ready to plunk some cash down for a pair of Dayton IB 15"s but the GR woooofers sound mighty good!
I already imported the parameters in ISD and this is what I got for sealed:
Volume = 1.857ft^3, Frc=37.4Hz, Qtc=0.758. Nice Q with low volume but the tuned frequecny is quite high.
2.6ft^3 is pretty nice for 20Hz tuning with the passive radiator.
Danny,
Do you have a 15" version in design btw? I wouldsn't mind using a couple of those in isobarik format for a 15ft^3 birch coffee table I have in mind doing? That would be sweet! :D
Thanks for the advice!
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Danny,
Do you have a 15" version in design btw? I wouldsn't mind using a couple of those in isobarik format for a 15ft^3 birch coffee table I have in mind doing? That would be sweet!
Nope, I am only going to do a 12 incher for now.
15ft^3? You could just about put six of my 12's in there with PR's.
Now that would move some air.
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:o :mrgreen: :o
Six of them eh...?
Tempting but rather pricey I'm afraid for 6 subwoofers and 6 PR's... :?
I'm leaning towards "small" 2.6ft^3 GR 12" woofers/PR's for each of my Line Arrays for stereo woofin' and a couple of 15" IB's in isobarik sealed in the 15ft^3 coffee table for sub out HT duties! :D 8)
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Tempting but rather pricey I'm afraid for 6 subwoofers and 6 PR's..
$900 for drivers and PRs isn't so bad - when you look at what you're getting to move the air ... in addition to an eviction notice. ;)
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Six of them eh...?
Well if you have that much air space to work with...
Tempting but rather pricey I'm afraid for 6 subwoofers and 6 PR's...
Well maybe compared to only one pair of 15's.
So space is a consideration for the front subs but the coffee table has to be big enough for a couple of dinner plates, drinks, and a stack of remote controls, plus hold them up to the right height, eh.... :wink:
So for the coffee table space is not as big of a concern as price. Hmmm, I have no good answer.
Hey, how about 2 of my 12's with PR's. You won't spend to much, and you still have room for a cooler full of beer in the coffee table too? :mrgreen:
Okay, I better get back on figuring out the name and model numbers. Any more ideas to consider?
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Someone can set up a pair of subs to 'look' like they're stereo, but the waves are so HUGE and totally non-directional that they aren't stereo.
I've got dual subs and have tried them in dual corners and together and find putting them together gives a tighter sound and will make the output the loudest making the dist. and amp needs the lowest.
Also like Danny also pretty much said sub bass and everything above it are like two diff. animals.
Optimal pos. for a pair of speakers is typically not optimal for a sub.
Corner loading isn't always the best, but it's usually the best IMO.
Just some thoughts in general about thinks to think about before someone decides how many direvers needed and where they'll go. Placement can be worth more to output and musicallity than adding drivers.
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Ok, how about "GRaceful" for a name?
Since you don't necessarily love huge Xmaxes and stuff like that.
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"-Since you don't necessarily love huge Xmaxes and stuff like that.-"
Wow, I didn't realize 16mm XMax was small to you. 12's with a lot more cost a LOT more from what I've seen, and are the most extreme long throw designs out there I thought.
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Since you don't necessarily love huge Xmaxes and stuff like that.
Don't get me wrong. I have nothing against long X-max's.
That is kind of like having an amp with a lot of head room.
I just believe that if your focus is on sound quality you don't drive woofers to their limits.
If you need to move more air than half the capabilities of a woofer then use two, or even better, four.
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As loathe as I am to question an obviously very experienced speaker designer like Brian Cheney, wouldn't the drivers with their very different electromechanical parameters make any bass loading design a very poor one at best? Everyone knows you don't take two different types of drivers and load them to a box, because they will have different resonant frequencies that need to be controlled by the port. One driver will have an uncontrolled resonance, or one driver will have its way with the other, or various other problems. This doesn't agree with standard T/S theory.
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Rory,
Have you listened to Brian's subs?
If you had, you wouldn't be asking the question.
I have two Larger subs and think they are very, very good.
George
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Rory,
Since you're asking Brian C. a question you should be asking it on his forum and not here.
Good luck getting a straight answer too.
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I don't think he is asking a direct question to Brian.
I believe he is questioning his design, and his questions are quite educated.
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I don't own the VMPS larger sub, but I heard one extensively a year ago at the Midwest Audiofest. I spent most of the weekend in the Bolder/Teres/8th Nerve room guarding a mini keg of beer :wink:
The larger was one of the best musical subs I've heard. Wayne from Bolder set up the room using an 8th Nerve roompack. He also used an EQ on his QMS sub amp set with some RTA laptop program.
I suspect that the Larger sounds so good because of the very large internal volume as well as the additional mass (mortite) loaded onto the passive radiator. I"m guessing this additional mass might make the passive SEEM much larger than it really is.
Why two different size active drivers can mesh so seemlessly, I haven't a clue....but they sure seemed to me that they did. Again, maybe it is the "tuning" using the mortite on the passive that helps with this.
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GR-CustomAction
GR-Accelerator
GR-SOX
I've been spending too much time with software development. But the terms work.
Al
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Sorry,
I just didn't want to see another designer get pulled into this forum. Obviously Rory wasn't directly asking Brian C. the question since he asked it here, but it seemed like a trigger to a big can of worms.
Just trying to help steer things a bit to keep them cool and in appr. places.
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Hey, I just found this thread! Good ideas, Danny. Best of luck with it and I recommend you experiment with a dipole line array.
Here's my name suggestion: The GR Zeuss "GR Research provides your complete speaker needs from A to Z, Alpha to Zeuss!"
What's the prize? :mrgreen:
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How about Zed?
Beta
Beat-a
How about GR Research Pandora's?
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Here's my name suggestion: The GR Zeuss "GR Research provides your complete speaker needs from A to Z, Alpha to Zeuss!"
What's the prize? :mrgreen:
Hey, I like that Hank! Kinda goes along w/ the whole "masters of the universe" theme :)
Of course Danny could go with the old classic, "Widow-maker". Or, given the fact that this product is designed to make a lot of loud booming sounds, you could call it the "Home-wrecker".
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Thanks, Jon. Following your theme, just be right up front and call it:
The GR Research DECREE :wink:
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Here's a finished pic in a good old Black textured box.
The PR is on the opposite end from the woofer.
(http://www.gr-research.com/images/blacksub3.jpg)
The box is heavy braced 3/4" MDF with a double layer front baffle for the woofer to mount to. Then lined with Blackhole 5, of coarse!
I am very pleased with the sound. It plays deep, smooth and very musical, but the real surprise was that it hits pretty hard too.
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looks good Danny,
Can not wait till they arrive :mrgreen:
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(http://members.shaw.ca/awooley/pictures/cherry1.5ft.JPG)
(http://members.shaw.ca/awooley/pictures/cherry1.5cft.JPG)
Ok now just waiting for the Driver and PRSS.
Cut for new 360 watt amp with remote.
:mrgreen:
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Oh yeah, another question.
I was considering your suggestion of using 6 of each of the woofers and PRs. Can the PR's be mounted at the bottom of the box?
If not, that would be a showstopper for me...
Thanks,
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Can the PR's be mounted at the bottom of the box?
The suspension of the PR is fairly stiff. I don't think down firing the PR will be a problem.
Just keep it up off the floor a little.
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Ok now just waiting for the Driver and PRSS.
Cut for new 360 watt amp with remote.
:mrgreen:
what'as the third round hole for, if using one active & one passive?
thanks,
doug s.
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Here's a finished pic in a good old Black textured box.
The PR is on the opposite end from the woofer.
The box is heavy braced 3/4" MDF with a double layer front baffle for the woofer to mount to. Then lined with Blackhole 5, of coarse!
I am very pleased with the sound. It plays deep, smooth and very musical, but the real surprise was that it hits pretty hard too.
ok danny, how much $$$ for a complete kit?
thanks,
doug s.
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I'm not sure what subs fit the box Al pictured.
That may be something he made for an 8 and a pair of PR's.
I am going to introduce the 12" woofer and PR for $144.
I may offer an amp for it at some point in the future.
For sure, I'll offer a Black textured box through Al that will not be very expensive.
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The 12" and twin PRS not a single.
I have made this exact cabinet for a customer as well for the XLS12" with twin CSS 10" PRs.
May even get a head to head with Dannys and twin PRS as well.Time frame comes into play.
Al
This twin PR single driver from GR will be for a design I am going after.
Smaller 1-1.5cft cabinet.
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Can the PR's be mounted at the bottom of the box?
The suspension of the PR is fairly stiff. I don't think down firing the PR will be a problem.
Just keep it up off the floor a little.
Thanks Danny, I will.
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The woofers and PR's should be in stock by July the 15th.
Part number for the woofer is SW12A.
Part number for the passive radiator is PR12A.
Too simple huh? :D
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Just wondering when you might have some test results from the new subs. I'm REALLY itching to order 7 a/v-1's for my HT but I'm holding out until I decide which subs to get. I like the small box size and LF extension on these woofers.
By the way, does the motor on these use a shorting ring or any other stabilization for lower distortion?
-Matt
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Why would deciding what sub/s to buy hold you back from ordering the A/V1's?
I don't get it. If anything having the A/V1's would mean you'd be able to test out some subs to see how they work with the A/V's, but really any good to great subs should 'match' these speakers.
Also, if you're building 7 A/V 1's as kits I'd think you'd want to get working on that which would give you some time before they're complete and ready to be matched to any subs. And then guessing Danny will have all the info on his new drivers and cabinet designs by then.
In the end if the GR sub/s don't look like what you exactly want... just get diff. subs for your A/V1's you said you're wanting to buy.
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All the specs and parameters have been posted here.
Optimal sized box with a -3db at 20Hz is only 2.6 cubic feet.
I have been playing one for a while now with our speakers, including A/V-1's and it works great with them. It should. It was designed to.
Several things in the overall design have been incorporated to lower distortion, but a shorting ring is not one of them.
There are pros and cons to increasing the woofers ability to play up higher.
I don't see the need to play these above 300Hz. They do play smoothly to 500Hz and I believe that is high enough.