This is probably one of the best if not the best channel about room acoustics ever. Everything you need to know explained in a very simple but effective way. No need to scroll and search in hundreds of forum posts. This is gold! Keep up. Highly appreciated.

100% of spiders approve of air gaps between the panel and the wall.

Soon after I wonder about an aspect of room treatment I get recommended a video where you cover the topic. It's invaluable what you're doing for us newbies of home studio setups. Thanks a million

Just discovered your channel….. This simple formula you described is priceless!. I was always told it can be a good idea to leave a small gap behind hung panels, but I never knew there was a specific formula behind getting the best results. Great stuff !! 😉👍

You have authentic depth of knowledge, and you're quite skilled at conveying complex ideas clearly. This was a real treat to watch, and the best I would ever expect to find for free. Thanks so much for sharing so generously.

I am about to do treatment for my first studio. This information is well explained and very timely. Thank you!

Excellent video. Clear and concise backed by scientific principles. You obviously know exactly what you're talking about. I'm an immediate disciple. Many thanks.

You have a very optimistic view of how these air gaps work. The models in that absorption calculator assume that the air gap is enclosed, and that all of the sound is therefore funneled into a wall and back through the absorber. But that isn't the case when you're talking about air gaps behind a mounted panel, this gap is not enclosed. So a good amount of the sound (especially from the outer 50% of the panel) will not make it back through the absorber, but instead spill out from around the unenclosed air gap. If you wanted this to work like it does in the models, you would need to build that air gap into the panels themselves, so that they're enclosed by a rigid material.

one of the best videos in the topic I've ever seen ... now to actually execute the ideas in my "bedroom" studio :)

Thanks Jesco, for another informative video. I really appreciate you sharing this knowledge.

Jesco, thank you so much, you've opened my eyes on acoustic

keep it coming, best treatment advice on the tube !

Absolutely amazing content as always. Learning so much from these videos. Thanks for sharing. The channel should do really well going forward 👍👌

Very good and logical walk through of acoustics wave speed vs spl.

Amazing, really - thank for the session on what to be thinking about before you start hanging your absorption panels..(I was just in the process of doing this) ...and thank you for the valuable set up procedure on how to hear the sweet spot for your speaker placement, I was able to understand the process and it gave me more of an insight on what I should have been focusing on - Thank you Acoustic Insider!

What can I say but, Excellent information and presentation.

Very well explained and clear with the right balance of theory and practical application - I will be checking out your channel - Thank you !

truly incredible work you are doing here!

Great work and well documented, I am definitely keeping your contact!

Great videos. Most of it actually usable for home listening rooms also. I don't want to build studio but I need to treat my listening room in order to achieve balanced and natural sounding sweet spot.

You articulate very well 👏 fair play, thanks!

Very interesting, so if I understand the conclusion at the end correctly, it would be beneficial to have an air gap (all be it not more than the core size), but if you have the space and resources it would still be better to just have a thicker absorption panel that would take up the same space (panel + gap). I did elevate some of my wall panels with acoustic foam on the sides of some tiles (so it has a gap to the wall inside but doesn't have open spaces on the side). But next treatment I will just get foam sheets to just have a thicker panel to elevate them. Thanks a lot! Great channel!

Always excellent and applicable information, Jesco. :)

Thank you for this channel! you are helping massively

Jesco! this answers my question from your last video. I had built panels last year that were only 4" thick and after taking your courses I learned that they should be 6". Any new panels I built would be 6" but I already invested time and money in the 4" panels, so I ran the absorber calculator and figured out that I could get slightly better response with a 1" gap. It worked perfectly and I noticed a difference. I also used this same approach to calculate the placement of freestanding temporary panels. The only door in my room is in a corner and bass tends to build up there so I placed a 6" broadband absorber during mixing sessions. I used the technique to calculate the optimal placement and air gap to the wall for the temp panel then I placed tape on the floor so I can quickly place it in the same spot. Thanks for the advice !

Amazing content as always. Thx Jesco!

Thank you for another great one Jesco!!!

Great, clear explanation

This is great, good job Jesco!

One more note on open-air gapping. I read a GIK mounting test using a 4" rockwool panel where one panel was tested flat on the wall and the other was tested with a 3" open-air gap. The 3" air gap did get a small boost in absorption coefficient starting from 160 Hz and down, but started to create an absorption coefficient loss starting from 630 Hz and up. So no matter what, you don't get something for nothing. It's a tradeoff. Again in this situation though, it's still better to just use a 6" panel over a 4" panel open-air gapped.

Great video, great channel. Thank you.

Great video, thank you for a fact based explanation!

Perfect video, thank you verty much

Thank You, Much appreciated

Anoyher great video Jesco, thank you 👍🏼 ATB Peter

Super informative video, thanks for that. Does this mean that I can have air gaps for my corner bass traps instead of super chunks, and the absorption may be the same or even better?

I am glad I saw this. I have been thinking of making a diffusor by hanging a variety of panels of dry wall of a variety of sizes at a variety of distances from the ceiling. I know there is nothing new under the sun and somebody somewhere must have thought of the same thing. I wondering if a 1 meter by 2 meter panel of drywall say 3 cm from the ceiling might not end up acting as a bit of a bass trap?

Thanks for your guidance! 🔈

Great explanation! I have a related question... what would be the difference in having an absorption panel close/against the wall as opposed to having them hanging on a stand closer to the listening position, and say 3 feet away from left and right wall?

You are the man! Thanks a bunch

I have a 10cm thick ceiling absorber preventing me from early reflection at listening spot. Does this mean I have to hang this not more than 10cm from the ceiling to avoid the non-effectiveness in the lower mids? Thank you for all this incredible wisdom you share here with us.

Good video, great channel. thanks for the advice.

Great video thx for sharing. In this case I could away with flat panel bass traps instead of triangle 🔺️by leaving space. 8 inches panel and leaving 8 inches or more I'll be able to achieve that. Bast explained thx again.

Very informative and educational! Just signed to your channel! :)

Best video on the internet

Cool video, thanks, greetings from far Chile.

Really interesting video, thanks for the calculator! Would be keen to understand if it is possible to do similar measurements with a flat panel in a corner where the depth is then not just a fixed amount, instead deeper in the middle than the edges.

Thank you, man!

The absorber should be place as close as possible to the 1/4 wavelength position, where the amplitude is greatest and the absorption most effective. Longer wavelengths have 1/4 wavelengths farther from the wall, so the absorber must be moved farther from the wall to be effective, compared with shorter wavelengths. Please correct me if I am wrong.

Great channel, subbed and checking all your other videos :) I have a question though, going to build new panels soon, (200mm depth cotton wool) but i'm never quite sure which density would suit my needs. Any info on that ?

Hi, thanks for your videos, they are great! A shot question I have been pondering on... Is there anything to be gained mounting two thinner panels with a gap between them an then a gap to the wall? Or maybe a the second up against the wall...

Thanks for your awesome content! Very well explained and easy to digest even not having a lot of upfront knowledge. Is this (in a more moderate way) also applicable to living rooms where you listens to music and want to treat the room? I‘m thinking about the wall behind the speakers and basically building a big wooden frame with Pamela’s you find in centralized concert rooms and put absorption material behind sand possibly an airspace. In the living room I‘d not make this deepen than 10cm though as it would otherwise interfere to much with the room and it‘s usage as a living room

i have watched about 20 of your videos since saturday night and feel transformed. i have learned essential things and really appreciate your videos and advice and how well structured all of it is communicated. so, i am planning to get into building absorbers and bass traps (and maybe diffusors later, if i still got the need and motivation). atm i am calculating the air gap behind the panels, but i have an important questions: do i also need an air gap behind the bass traps? and if so, does the gap have to be all around the bass trap or just in the corner? i thought about building a standing plate for a bass trap and started wondering, if it would be neccessary to have it be a few centimeters wider all around.

Great info. Thanks a lot

Well explained

I heard air gap is important between window and acrylic window insert. Also I'm planning to use 2 exterior doors with space in between for our home studio.

With a 4-inch thick slab of acoustic foam and no air gap, the Porous Absorption Calculator says absorption is down to 80% at around 400hz. If you split the foam into alternating 2-inch slabs in a checkboard pattern, you can get different air gap depths between adjacent slabs. With a 4-inch air gap, 80% absorption drops down to 300hz, but there's an unwanted dip at around 1200hz. With a 6-inch air gap, 80% absorption drops to 200hz with a dip at 900hz, but there's a secondary 100% absorption peak at 1200hz. With a checkerboard array of 2-inch slabs and an upper slab air gap of 4-inches, seems like the 900hz and 1200hz dips would be compensated by the absorption peak of the complementary slab. That would give you an octave lower 80% absorption frequency while cutting the foam thickness in half.

Another awesome video..

Using the largest depth with a single layer over a larger area... But doubling and triple layering the centers or targeting first incidents etc could result in best results... I have those IKEA square shelves with the open back.. Covered and stuffed and off the wall a few inches. With stuff in them.. Books.. Guitar pedals. Batteries.. A coffee tub.. Surprisingly good compromise.

Yes, good advice👍

How would that work if the panel is put in a corner? (Meaning the air gap would be triangular). Does the same rules apply in terms of ratio? Keep up the good content!

Another great video. I'm wondering how things would be affected by storing things in the air gap. I use my space primarily for mixing but also to record drums a lot and sometimes rehearse too, so space management is important and I have a lot of gear to store (multiple drum kits...). So I have a potentially crazy idea of putting floor to ceiling storage on the back wall (50cm deep) with various drums, stands, mics, cables etc and putting a "wall" of moveable gobos essentially in front of that. Would those panels then need to be 50cm deep themselves to have any effect? Would they even do anything to low end if there is stuff of various shapes and sizes behind them?

Very very useful info, and that site is a great tool. Question though, what density is ideal?

So does this mean you want to have varying air gap depths to cover that dip in the midrange? Adding some blocks of absorber on the back in air gap, to get the best of both the airgap *and* the double depth of absorber but without the cost of having a double depth of absorber over the whole panel? Or perhaps alternating airgap and full depth panels (again to reduce the cost of absorber).

hello my friend i wanted to ask you I have small room, and first I want to sound good for mixing for example and second I'm vocalist after i put a ceiling acoustic panel on the ceiling my room sound has changed to better sound, but i think a diffuser would be better, what do you think? what kind of difusor could i place on the ceiling? thank you!

I just came across this video, what an excellent explanation thank you! I have 1 follow up question, so for example assuming a 2" sound absorbing panel and a 2" air gap, would a 2" thick Rockwool inside of a 4" deep frame, mounted flush to the wall, still be the same as a 2" deep panel, mounted 2" off of the wall?

Great video, thank you. To counteract the dip in mid-range frequency absorption with a large gap, would it be prudent to put an additional layer of absorption on the wall (so effectively double layering the panels, one against the wall, one a few inches off)?

good explanation. Would this be true of super chunk absorbers? Should i fill the entire core with Safe N sound, or maybe just the front, to leave an equal gap of dead air behind them?

Good video and the PDF was an interesting read. My studio is visually a mess but sonically I'm delighted. Gradually I am tidying the room but the question is, how much harm will tidying the room do to the acoustics? I'm seriously considering putting up drapes to simply hide the cluttered shelves! 😀

Love the channel, been binge watching, about to build a studio in my guest house. Hypothetical question, just out of curiosity: How would a multiple panel/gap "sandwich" combination compare to single panel/gap of equal total thickness? Lets say we cut a panel in half by thickness, and use it with half the gap between the wall and first panel, then another equal gap between panel one and two. Would that affect absorbtion in any meaningful way? Taking it further, would a increasing/decreasing or shuffled thickness/gap multilayer sandwich make any perceptible difference? Lets say | is one unit thickness, and space is a unit gap, something like: room||| || | wall

Was debating between the whole back wall with all 3” Safe and Sound and pull grill cloth down over or making panels. I guess your recommendation would be to make panels. It’s a heavy bass room.

Hi Jesco, can you make a video about sit-stand studio desks from an acoustician perspective? Is it even possible to use sit and stand configuration without perceiving room acoustics totally different? If the sit-stand desk can actually work, would you suggest having also sit-stand monitor stands?

Scientific and (a) Terrific.... help.

Hi..... thanks for the video ... when making panels with rockwool . how to make sure you don't have any loos fiber in the air for health problems ?

Using the Porous Absorber Calculator at the acousticmodelling link in the video, the half-wave dip in absorption you point out is much less of a problem when the calculator's Random Incidence option is checked. Does this imply that using pyramidal or triangular-ridged acoustic absorption foam is a better choice than flat-surfaced foam for deep air gaps?

great videl man! I'm wondering what the difference would be between just placing the panel further from the wall vs kind of making the frame of the panel deeper so that you effectively create a closed air pocket. I've heard that, that's how you should actually do it, but I was never able to test and compare both versions. what do you think?

Excellent

Does the same go for when hanging panels overhead as a cloud? Distance fro panel or cloud to ceiling?

I am thinking in using now, silk screening mesh fabric to cover my panels. It's made of nylon, stretches very well, and allows the sound to go inside the rockwool 100% letting it do its job completely well, the way rockwool is supposed to work. It is not expensive if bought by the roll at Walmart. Using the correct opening, won't allow the tiny pieces of rockwool get out of the panel, that are really bad if you breath them. What do you think? .

Hej Jesco, do you have any experience with the AVAA active bass traps, are they any good, the price aside?

I'm building large (4' x 8' x 6") panels to treat a large rehearsal room with 14' ceilings. Any practical mounting tips for wall-mounting larger, heavier panels with a 6" air gap? Really struggling to come up with a good way to do this. Thanks!

Jesco, I have noticed even with a 10 inches of porous material (in my case Rockwool density 30kg/m3 [9000 Pa.s/m2] ) and a 10 inch air gap provided, I am able to see only .5 or .4 absorption coefficient in the graph for low frequency areas. What I am asking is, will this much SAC will help to tame some serious low end and make things better? Will this SAC improves with larger surface area for the panels, especially for low frequency management?

Can you make a 6in panel with 2inch panel and 4in panel tied together in a frame? Or am I better off finding the 6in panel?

Also fellow Mitmensch mit male-pattern baldness wollt ich nur mal sagen: sieht rasiert richtig gut aus ;)

Just discovering this channel and it's great, thank you! Wondering about corner traps with this concept. Corner traps from the center of the panel to where the walls meet usually have a fairly large distance. Does this concept apply to corner traps as well?

When you switch that calculator to "random incidence", that effect totally disappears and then it's just deeper = better. Now I'm wondering if I should back-fill my absorbers for more even absorption. EDIT: For treating modal frequencies, 0 degrees incidence works since those standing waves hit the wall dead on in a rectangular room. So it's better to use the material to cover more area if making it thicker doesn't increase bass absorption.

Hi, do you sell the plots how to make the absorbers/basstraps, basstraps/diffusers you use? thanks

Brilliant

hi , thanks alot for your help , i checked the site and i have a question , what if we use 2 layers of 4 inch panels each one with 4 inch air gap ? does it work ?

Thanks

Hello, Thanks for all those informative Videos, My Room is small. 13'L X 12'W X 8'H so working with the 38% rules my Listening sweet spot is about 5' from the front wall. I`m looking to install two 6'' D X 24''W X48''H Pad behind my monitor. But it`s getting hard to keep a equal triangle with enough stereo width in that 5' space . So Should I keep my Pad Flush to the wall to keep maximum distance between my monitor and the pad or add some space and get the Monitor closer to the Pad. Thanks

Great video, thank you! To-the-point, and explained the 1-to-1 ratio of thickness to air gap very clearly. I am currently about to build acoustic panels with 3.5” thick mineral wool insulation, so I’ll be planning on building stands for those panels so that they sit 3.5” away from the wall. I know it’s not 6 inches thick (which would be most ideal), but I also don’t have a lot of room for 6 inch thick panels in my home theater testing room that I’m building for my own channel. Not the most ideal, but better than no panels at all. 😁🤘 Thanks again! You have a new subscriber!

Is this gap also more effective with bass traps in the corners? I've seen another video where they turn the triangle Basstraps in the other direction -> with the 90 degree angle not to the corner but to the middle of the room. In the end it looked like a square because you haven't seen the gap behind it.

Some acoustic panels come with a solid backing material such as plywood. In this case I assume that an air gap does nothing, since the wood back acts like a wall. Correct?

I am making my own panels and can make any size and shape and thickness I want. I have covered all tri corners and bi corners, and near reflections and some rear wall. I still need to control main room modes, about 90 Hz and 120 hz, in my rectangular room. From your video I realize I need thicker bass traps with a gap, behind them. So is it better for me to make some thicker traps and leave some wall exposed to let highs and mids pass a little? Or should I continue and cover all walls completely? Should I put a thin ply layer, maybe 7mm, with holes, on the front of some traps to reflect highs and mids but still trap bass?

I’m curious, o guess we’re assuming the gap is against Sheetrock?Would the measurements change if the wall was treated? For example: if I had a room that was treated with 2 inch, then added 6 inch with 6 inch gap in various spots as needed better somehow? Rather than just having a gap with sheet rock.

He's right! However for me personally, I wouldn't recommend anything below 4" as your main reflection points(right behind speakers, wall right behind listening position should be at least 4" IMO with at least a 2" spacer, I also feel that with the 2" spacer there is less of a mid dip.). And for my personal preference I find that the low mid dip is still there a bit with a 1to1 ratio. It's very small but for critical work, I have found it can play a bit of havoc if you can't compensate for that in your workflow. Of course that could just be my particular ears I guess, cause most people think the 1.5db dip is not noticeable! But these guys are much more knowledgeable than me. I'm not the pro here, just expressing my personal experiences!!! Oh and for bass, always go big! Like 12"! Or for bass traps do 6" core material(RockWool is best for bass) with a 6"air gap housed in a 12" frame, open back is best as well IMO for bass traps! Especially in corners!

Could you please explain why do you suggest caring about base traps while for the same money you can cover 2x (or 3x) of wall space with thinner foam for the same money? The low band of human ear directionality (phase-sensitive) is centered around 500Hz, and covering down to 300Hz (with an air gap, on -3dB) may appear to be more beneficial than going into huge room-eating expense with base traps (which you can eq electronically for a rather wide sweet spot).

Question for you…I see you have slat diffuser/absorbers, how do you determine the size and positioning of the slats?

Thank you so much for providing this knowledge. I've been moving back and forth for months now, trying to reduce low-frequencies in my mixing spot. With your tutorials i start to finally figure it all out. Thank you, thank you, thank you. Sub-ed!