Author Topic: GIK Acoustics D1 Diffuser  (Read 8864 times)

Offline bpape

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GIK Acoustics D1 Diffuser
« on: July 25, 2007, 10:42:01 AM »
GIK Acoustics is proud to introduce our newest product – the D1 diffuser. The D1 is a new design which combines the best of a standard QRD along with a unique curved profile to extend the useful frequency range far beyond a standard diffuser of this type and size.




The D1 is made from strong, lightweight ABS and is paintable to match your
room’s color scheme.

*Fully tested
*Out performing diffusion costing 4 times as much
*Paintable
*Super cool looking
*Easy to mount
*Available in White or Black

D1 product info

Learn more about how diffusion works


For more information or to discuss how diffusion may fit into your room
design, contact us at: glenn.k@gikacoustics.com


Bryan
« Last Edit: August 09, 2007, 11:46:15 AM by bpape »
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miklorsmith

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Re: GIK Acoustics D1 Diffuser
« Reply #1 on: July 25, 2007, 02:22:52 PM »
Cool!  In what situations would you recommend diffusion versus absorbtion?

Offline richidoo

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Re: GIK Acoustics D1 Diffuser
« Reply #2 on: July 25, 2007, 03:41:29 PM »
Congrats on the new product Bryan!! It looks awesome!

Mike, I am not an expert, but I did read Peter D'Amato's new book. OUCH! That hurt (pocketbook and brain cells.) but it is very interesting, (if you find acoustic theory interesting) :D

Diffusion would be the best choice to stop reflections in a small room used for critical listening because it reduces distortion without removing any energy from the room as do absorbers. Removing energy makes the room sound dead if overdone, which his often necessary to control reflections solely with absorbtion. But diffusion has limitations in application and cost. A diffusor that works as well as a 4" thick FG absorber at 100Hz would be huge and very expensive. So absorbtion is more efficient in size and cost than diffusion at stopping reflections at frequencies below 800-1000Hz. Cheaper diffusion products won't do a good job below 1Khz, but a homemade quadratic residue diffusor made of wood in a manageable size can work well down to 800Hz or a little lower. Below that, absorbers are the best choice for stopping reflections. That's why the real experts say you need some of both when you want to really fine tune the room and are working with space and budget considerations. Without either, you could do a lot more diffusion at lower frequencies and maybe gain a little bit nicer sound. Some recording and mastering studios do this.

IMO, adding as much diffusion as possible is the best course, AFTER you already have enough absorbtion to handle reflections in the sub 1kHz freqs, and most of that absorbtion would go in the corners. The diffusion will break up the reflections on the remaining flat wall surfaces and restore the liveliness, but better than normal refelctions, it is diffuse reflections! Lively with no interference with your direct sound from the speakers - at least none that the brain would notice.

The rear wall, then front wall, then ceiling, then side walls are probably the best order of effectiveness for adding diffusion. Notice that these surfaces have gradually increasing angle of incidence from the source. If the side walls have a more normal incidence than the ceiling (farther away) they could come before wall, but their distance would reduce the value of diffusion also. The more normal the incidence (sound hits straight on, 90 degrees) the better for typical diffusion products. Absorbtion efficiency is less sensitive to angle of incidence than typical diffusion products.

Please correct me if any of this is not quite right, Bryan! Thanks
Rich

miklorsmith

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Re: GIK Acoustics D1 Diffuser
« Reply #3 on: July 25, 2007, 05:11:43 PM »
WOW, thanks Rich!

Offline Woodsyi

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Re: GIK Acoustics D1 Diffuser
« Reply #4 on: July 26, 2007, 05:13:51 AM »
Very nice Rich.  I am still using absorption behind the speakers on front wall on account of believing in the merits of LEDE concept but I agree with using both. 

Questions Bryan.  Which is better -- using a bunch of them together on a wall to form a big panel or spacing them apart for broader coverage?  Can diffraction orientation be rotated or should it be maintained throughout if multiple units are used?  What prime number QRD is it?
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Offline Carlman

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Re: GIK Acoustics D1 Diffuser
« Reply #5 on: July 26, 2007, 05:24:56 AM »
Looks cool but are they really 6' deep?  Might want to fix that typo on your site.

That's a very interesting design... I might be very interested when we get into the new house.... However, I don't know how much I'd need.  How do you determine that?  (for a given area, say a 12' wide back wall)

-C
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Offline bpape

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Re: GIK Acoustics D1 Diffuser
« Reply #6 on: July 26, 2007, 05:27:24 AM »
Hi Guys.

I'll agree with Rich on some points and expand a bit if I may.  I 100% agree that a mix of absorbtion and diffusion is in order in almost all rooms.  Too much absorbtion can in fact make things dead and lifeless. 

What we need to understand is that there is more at play here rather than just frequency response, impulse response, and killing early reflections.  Every room for a specific application has a target decay time.  Absorbtion will help you reach that.  This is particularly critical in the bottom end of the spectrum.  Once the target is reached (and with the absorbtion in the proper places) then diffusion becomes the finishing touch.

On the front wall with a normal speaker, I much prefer absorbtion.  With a dipole, it's a slightly different story but that's for another discussion.  The reasoning on the front wall is to eliminate smearing of the soundstage coupled with providing SBIR control.  While diffusion makes the soundstage 'bigger', IMO it also causes it to lose focus.  George (Zybar) tried my recommendation of moving his diffusion from the front to the rear and I think left it that way finding a more 'right sized' and focused image)

Rear wall of the room is a tricky thing.  IF you're sitting far enough away, diffusion can work very well.  That said, sometimes you'll have a huge frequency related null off the back wall down in the bass where only absorbtion can do the job.  In that case, it's a trade off.  Sometimes absorbtion in the center and diffusion on either side works - each room is different.

As for side wall reflections, that's a matter of taste.  I personally want something that will deal with the entire vocal range for the reflections.  That means absorbtion as even our diffusor only goes down in the 500Hz range (pure physics - they'd be just silly huge to go to 200Hz).  Now, on the back half of the side wall is a different story.  That's somewhere the is normally overlooked and untreated but can add a ton of life and spaciousness to the sound.

These are basically a derivation on a 7 prime.  They're designed to work best in groups with a bit of spacing between them to take advantage of the wall as another 'well' and also to allow the additional reflection and scattering off the sides of the units as they're exposed.

You can orient them as you wish depending on situation.  We're actually going to be doing some testing of a diamond arrangement with each one rotated 90 degrees to the previous and iwth about 4-6" between them.  Not sure when that will be done for official purposes.  What I can tell you is that we had a few customers who preordered and all of them have given us nothing but  :clap: so far.  One person did the diamond thing on his rear wall and on the ceiling and absolutely loves the results. 

Now if Glenn will just send me a few to play with....

Bryan

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Offline bpape

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Re: GIK Acoustics D1 Diffuser
« Reply #7 on: July 26, 2007, 05:31:08 AM »
Carl,

Thanks for the catch - you proofread till you're blue in the face and you'll still miss something!  :duh

As for how much you need, it really depends on the room, the usage, and the number of seats.  In a 12' wide 2 channel room, I'd either do the diamond I described above or use 6 panels set up as 3 columns, 2 in each column with them a few inches apart in each dimension.  On the side walls, you can still do the 2 high but you can space the pairs farther apart.

Bryan
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