This is pretty consistent with everything I’ve ben hearing about bass traps so far. In a hopelessly small room, you just cram as many in there as you can possibly fit, and hope it doesn’t create an aesthetic clusterfuck. This is some insane bass trapping, but from everything I can tell, this is about what it takes to get a room this small to start to balance out.
…I really like what this company is doing. They sort of concede that Ethan makes a higher quality trap, but his are ~very~ expensive. I have real traps stuff in my vocal booth and all GIK in the control room.
Dave and I are both using this stuff…anyone else on here go the GIK route?
Hey @AlphaVictor, GIK told me the ‘alpha panels’ (The 244’s with diffusor grids) are mostly cosmetic but helped keep the room from being too dead because some of the frequencies bounce off. But they said the diffusor plate itself is doing absolutely nothing as far as scattering frequencies because this room is far too small for this to possibly make a difference.
On your calculations, how big does a room have to be in order for diffusion to do anything helpful?
after suffering through the annoying “uplifting music” of the video…
those are 23N diffusers yes (work from 678 hz onwards), I have heard about them being used together with absorption but not in the way their alpha panels are using them. The hybrids are still questionable for this very reason:
In theory you cannot mount a diffuser on top of an absorption panel because the internal surface of the well (cavity of the diffuser) has to be pretty reflective. If its replaced with absorptive surface, the behavior could be anomalous. No diffusion would take place.
When they say, they mount the N23 on top of broadband absorption, I am not totally sure what they mean.
It could be done 2 ways:
Case1 : where a completed diffuser is placed on top of an absorption panel (could work in theory because sounds lower than 678 Hz would travel through the finished diffuser and into the absorption panel)
Case 2: the wrong way would be to put a diffuser partially finished (as the bottom cavity of the diffuser replaced by absorption)
Since I took the ones that were covering the fireplace and put them on the ceiling, I was gonna order these in Mahogany to match the fireplace and the mantle then found out they can’t customize the height. They’re an inch and a quarter too big.
So I’ll have to settle for whatever fabric other fabric is the least obnoxiously looking on the brick fireplace and hearth.
they could work or not work based on how they are mounted. They will not work if its case 2.
You can most likely test it by checking inside the slits , if the bottom surface of the slit is an absorbing surface, the diffuser wont work as the bottom of the diffuser has to be very reflective surface
In that case, it is basically an absorber with a cosmetic on top.
If its properly designed it would be case 1where both could technically work.
The N23 comes in 2 designs, N23 just means that the prime number 23 was used to calculate the pattern of the diffuser. It could be circular (above as shown in the Gotham 5") or it could be linear as shown below in the 6A Alpha 6"
the 6" is the depth of the diffuser panel of the alpha and 5" is the depth of the Gotham.
What I am not sure about the 6A is that whats behind the slits (cavities). They say in the video that the diffuser and the absorber are combined… based on the type of combine it is, it could mean 2 entirely different things.
The bottom of the cavity must be a reflective surface for diffusion to work otherwise its cosmetic only
I guess I would have to physically see one to know. I am sure they probably thought about it and they wouldnt just launch a product that claims diffusion. What I am hoping for is that the body is absorptive and the internal cavity is reflective. Then it would both work.
sorry missed this question, The demo video of the alpha panel advertises a hybrid of diffusion and absorption, so not sure why a GIK rep would tell you that it is purely cosmetic. It is possible whoever you talked to was unclear on the specs of the alpha panels (or the one who made the demo video was).
Specs from GIK website state:
“Thin face plate has mathematical sequence of slots for spatial diffusion, but also allows low frequency waves to pass through to the fiberglass panel for low end absorption.”
What is unclear is whether those “slots for spatial diffusion” go deep enough into the fiberglass or if it is really just a thin plate? From the images it doesn’t look like they go deep (not sure) but they (GIK) would not/should not be advertising it as a spatial diffuser, if that is the case. This could be a marketing mixup.
If it really is a thin plate that just sits on top, then, there would be no diffusion going on but certain high frequencies could bounce off (reflect)…
In theory the Hybrid panels could indeed do “true spatial diffusion” and absorption together if they were designed like Case 1 (absorptive fiberglass cut into deep cavities with a reflective lining, see fig.)
We will need someone to physically see the depth of the Alpha panel slots and inspect the lining inside the slots.
I think this design analysis would make more sense (not made to scale, showing top cross section):
Only Case 1 is an ideal diffuser absorber hybrid, Case 2 is NOT.
If the Alpha panels are case 2 then the faceplate is pretty much cosmetic and serves little purpose. Reflections off a flat plate isn’t really ‘ideal’ scattering either, so It could potentially cause problems. Since, the alpha panel in that case would be technically just absorbing lows and reflecting frequencies in the range of 16khz+ directly back to the source (since the reflecting surface is not angled), it could create comb filtering if placed directly behind the speakers.
As for minimum room size and diffusion:
For diffusion to be effective, the listening position needs to be far enough away for diffusion to mature. The maturing distance depends on the wavelength of the lowest frequency diffused.
If in a true diffuser, let’s say the lowest frequency diffused is 565 hz (6 inch deep),
A matured diffusion for this frequency would form at multiples of 150% of wavelength, so the absolute minimum distance from ‘diffuser to listening position’ would need to be between 3 ft to 5ft. So you can see you don’t really need too much space for effective diffusion. Most spaces are larger than 5ft so that shouldn’t be a concern for most well made diffusers.
If it’s design case 1, what is the fiberglass going to be absorbing? If it’s only a few inches thick and mounted to a flat wall, it’s not really going to be absorbing low frequencies. And if it’s diffusing high frequencies, what purpose is the absorption performing?
If it’s design 2, some of the mids/low mids can be absorbed better without absorbing high frequencies as much, giving it a more natural absorption. But in that case, the plate could have been pretty much any shape, right? It could have been just a bunch of uniform circular holes and had the same effect, as long as the hole/surface ratio was the same.
I guess if the membrane on case 1 was super thin, it could be more effective on mids/lows.
the fiberglass would still be the same thickness 6inch. Only this time has thin slits cut out with super thin but reflective inserts slipped in to act as diffusive cavities. Only then it would work. As in the cavities would still diffuse the high frequencies (above 565 Hz to 4k) and the rest of fiberglass body of 6inch thckness would still be able to absorb (80-565 hz).
It wouldnt be the best absorption, but there would still be absorption in the same spectrum since density of the material is not going to change from addition of the reflective slits. It should still be able to absorb the lows below (80-565 Hz) it was supposed to absorb. There will however be some surface area taken out from cutting of the slits , so there would be indeed some absorption in Sabins lost, which can be made up by mounting an extra panel.
but I was able to confirm that the Alpha panels just have a thin faceplate on top of the fiberglass so its all theoritical now. The faceplate in the alpha panel is mostly cosmetic with some reflective elements. I am not too fond of it now. Its basically an absorber, not diffuser. Their marketing is pushing it …
Yes, a bunch of uniform holes would have a similar effect but with a slight difference
their mathematical pattern is creating reflective cross section of different widths, as in it would reflect only certain frequency ranges from certain co-ordinates on the face plate. At certain locations the plate is hypothetically 2 inch thick and in certain places it is 1.5 inch thick and some places 2.5in and some places 1inch etc. etc. They would have different high frequency cut-offs.
What they are hoping to get from that is a different reflection pattern than just the one created from uniform holes with uniform plate cross sections in all coordinates - which would reflect a similar frequency range from all coordinates of the plate.
All that is fine, I am still not thrilled that its a thin flat reflector stuck on top of fiberglass. The reflector is not even curved to even do basic scattering. Its not even a decent “scattering - absorption” hybrid, let alone a “diffuser-absorption” hybrid. Gotta love marketing.