Small Room Acoustics: Three Acoustics Effects You Will NEVER Get Rid Of - AcousticsInsider.com

[@NathanOakley1980]

No matter how much treatment I did, I could never get rid of the lawnmower noise outside on a Monday when I have the triple glazed window open. I could spend £30,000 on extra isolation and £20,000 on HVAC but I decided to just close that window on a Monday. Other than that, I spent around £5500 (pretty much what you said it would cost) on room treatment and I am *delighted* with the results! The only thing I did that you don’t often recommend was adding 4 tuned bass traps (after the standard treatment as you suggested) 2 x 40hz and 2 x 70hz (GIK Scopus) and they did do a great job of “shooting down” those very specific problem frequencies caused by Axial Modes (ceiling and long wall). Your advice has been by far the best on KZbin and I have basically done everything you advise. A massive thank you to you, I’m at the end of the 2+ year process and I definitely would not be as happy as I am had I not have found your videos. Thanks again.

[@djtommykeys]

I've listened to dozens of "experts" on youtube and you're the first one to mention "comb filtering," a term I am familiar with from instrument speaker design. You are the true expert. Great video!

[@Jean-Pierre.B]

Hello, you can get rid of floor reflection (if needed) by using a subwoofer positioned on the floor assuming the subwoofer can play above that frequency dip caused by floor bounce. As you mentioned the dip frequency depends on the height of the listening position, speaker height and distance (speaker listening position). If your floor bounce is around 130hz, your satellite has to be high-cut so it won't play that frequency, preferably higher. Your subwoofer plays under that frequency, preferably higher. Measuring in situ, adjusting crossover between main and subwoofer etc. needed. It's not room dimensions depending, same applies for bigger rooms. The only difference between small and big rooms (for that particular problem) is listening distance, consequently your x-over frequency will change. Cheers, Jean-Pierre B.

[@mu_on]

Clever technique, probably hard to effectively make it work practically, but thanks !

[@Jean-Pierre.B]

@@mu_onI've veen doing this technique for my clients (when requested) for years with great success. As long as your sub(s) can play these frequencies (above 150hz) and you can adjust the crossover frequency (most subs ave a fixed crossover frequency...) it is very easy to set...and forget. I would suggest you to use REW and play around, it is fun to do :) Finally, 'seeing' that dip, a very narrow one, is great sign, that means other problems are under controlled. Let us know if you use it! Cheers, Jean-Pierre B.//N&NA.

[@johantt2591]

There is one option that deals with all three (except learning where these comb filters are and how they affect your listening): reference on a good pair of headphones. Always a good option in small spaces.

[@billguitarvin]

Thanks so much for making this video! Excellent points to remember. I’ve often wondered, what if one got rid of the desk and used a tablet using WiFi to eliminate the desk bounce?

[@sundamusik]

I think when you've done all you can, it all comes down to how well you know your speakers and the room. Think it will take some time to learn how it all react in the space you're working in. Bless

[@danbriggs3106]

Jesco, you've saved my mental health!...I was non stop moving speakers and listening position all over the place trying to fix them for ...lets say ..a long long time. now I can relax let go and work on what I can improve. thank god lol thanks jesco

[@nottieru]

How about a mesh desk? Or a perforated wood desk.

[@Pummelfay]

I cant find any video on how you actually build those absorber diffusors. That would be amazing

[@PuglioInside]

Hi Jesco! Thanks for the video, I find your channel very useful for people like me, who are getting started with room acoustics. I ask you two questions, maybe they can give you an idea for future videos: do you think that tilting monitors upwards can help acoustics by changing the angle of the reflections? In case the computer screen is between monitors is it playing a role in the reflections pattern?

[@christopherhawthorn6647]

I’ve noticed that some mix engineers are doing away with the desk entirely, opting for a small tray just large enough to hold a keyboard and mouse, and use a larger computer monitor further back on the floor or rear wall. In such a case, what’s to stop someone from placing absorptive material on the floor in front of the mix position? Don’t we similarly treat the ceiling when we hanging “cloud” panels? Or furthermore, is there any reason not to change the angle of the reflective surface in front of the mix position (e.g. a large piece of of plywood on the floor, or an angled desktop surface ) so that the sound reflects at an angle that passes below one’s ears at the mix position?

[@jonathanknight8251]

The floor bounce issue very much can be addressed with speaker design. Look at the work of Roy Allison, Acoustic Research or JBL with their 43XX series of monitors. The trick is to use a three way speaker and mount the woofer at floor level. This will move the frequencies above which comb filtering begins to occur above its passband if you cross it over at 300 Hz or so. The floor reflections occur in the passband, but because the woofer is at floor level, the direct and reflected sound arrived in phase (or close enough for practical purposes). This of course would be problematic in a small home stupid in where your monitors are right in front of your desk, but in a larger room with no desk between you and the speakers, it works beautifully.

[@jonathanknight8251]

…home studio…

[@alexandre7634]

My internship mentor in a studio told me that floor reflections are actually a good thing and help us to spatialise elements in our environnement, but I need to look for a scientific research about that or something

[@leandrosilva6414]

Great Video as always! Cheers Jesco!

[@head_out]

Can someone please send me that treatment guide that Jesko talks about at the end? For some reason I'm blocked from accessing Acoustics Insider.

[@prod.ghxstghxst]

Quick question: I’m designing some panels about 5 1/2 inches thick, I had the idea of adding an air gap between two layers of insulation within the panel, so something like 3 inches of Rockwool, 1 inch air gap, 1 inch of Owens corning 703. Does anyone have any idea if this is just useless in that it separates what could be 5 inches of core density? I couldn’t find much on airgaps within panels themselves rather than just between panel and wall, thanks!!

[@cosmic040]

Actually the airgap does make a lot of sense close to the wall: That's where the acoustic velocity is lowest. Meaning porous material wouldn't absorb much here anyway. But an airgap in the middle of the absorber…?! imho that wouldn't help you at all. Quite the opposite: Your wasting part of the precious absorbent depth (trying to catch velocity-peaks @ 1/4 of freq. wavelengths)… with air = a gap with no effect whatsoever (afaik). I'd stick to the proven method: airgap = closest to the wall.

[@prod.ghxstghxst]

@@cosmic040 sweet that’s what I ended up deciding as well so I went with 5 inch wall panels and 7 inch cloud panels

[@MarcusAseth]

interesting video, I've recently received my umik1 and watching this video I realize I might have tried to equalize away the comb filtering you mentioned xD About equalization, can you do a video about how to approach it (I used REW and EQ APO) and what to aim for? :) For example, should one aim for a perfectly flat line? A tilted line with the bass more pronounced? How smooth should this line be? After my attempt at equalization, although the line follows an horizontal axis overall it is very "weavy" with constant up and downs of 3-4db, is that normal or the result of poorly automatically generated filters? :S Hope you'll make a video about this, I'm sure I've messed up overall and many could really learn from that :)

[@ELISHACAEZ]

Can't you put a shaggy carpet on the floor? I kept hearing about that when I first started researching room treatment and people say that it makes a difference (does it?)

[@frederickrodger7249]

Good video, thank you.

[@unclemick-synths]

I eliminated the desk a long time ago. The other two I live with but they don't bother me much.

[@ViktorNova]

Thank you, I needed to hear this lol

[@mohammad14382]

I tried many time to get the guide from the ling but never received any mail

[@tipipulkkinen]

You can actually do something to the desk reflection. I have 66 x 300 x 400 mm rockwool panels on my desk (in the desk reflection point) and the difference is like day and nite! Would not go back listening without them. Take a look at Raytown Productions video: kzbin.info/www/bejne/mGSyaZ2jebuNndU

[@pecacartun]

What about small (tuned to frequency of interest) holes in floor at the spots of predicted reflection's?

[@martinsouthall]

😂

[@dot.initial]

i really thought about drilling holes into upper half of my desk - it’s easy to do ….. maybe only in the area of the 30° angle ..

[@pecacartun]

@@dot.initial smaller in diameter then a ✏️ just that you can put one on the desk. :) But I talked about drilling holes in the floor - basically - anechoic chamber floor princip, but just in the region of reflection (of interest) zone. Of course that couldn't be done if You are on the upper floor, basically - if you have anyone below you.

[@andrus108]

No. 3 is easily reduced - don't mix in mono! Space the instruments around, heck even bass! :D (check out The Who's Live at Leeds as an example, guitar is panned hard right and bass guitar hard left.) And then it's down to isolating no. 1 or 2. Either you make sure there is no furniture and equipment between the speaker and your ears leaving only floor reflection, or you make the desk so big you only get the desk reflection. >:p

[@AlexLapugean]

Even if you don't mix in mono, there is plenty of mono (mid/sum) information, should actually be much more than the side (difference) information in a good mix. You cannot just pan all instruments to either side, and you still have drums/vocals that should definately be mostly centered. So at the very least, you have the comb filtering for some elements and not for others, which is still signifficant. And yes, you can reduce the rest, the point of this video was that you cannot really get rid of them. Maybe in some fringe cases i guess....

[@dodgingrain3695]

The floor can be treated to at least a limited degree with thick carpet, etc. If that's a good idea is a different subject ;)

[@guidokamper8005]

what about different material on the floor, eg. carpet vs. parquet floor? could it diffuse the waves?

[@joshua43214]

Yes to carpet - it makes a huge difference and it has a high WAF. That said, carpet directly on the floor is like a heavy curtain directly on the wall, it has very limited effect. It is a mild absorber, and a mild diffractor - mostly in the higher frequencies.

[@paulbishop2161]

No, because the wavelengths involved in the floor bounce are so long that the thin carpet won't do anything, it could even emphasise it in fact due to it absorbing high frequencies meaning that low frequency problems become more obvious

[@stupendousmusic4190]

👏🏻EXCELLENT👍🏻

[@cosmic040]

☝️Hey DIY-Nerds & Jesco : Any tips on how to tightly staple front fabric ▶︎ INSIDE ◀︎ an absorber-frame? 🤔 So far I did wrap my absorbers in fabric (tightly stapled on the back). But having the frame/wood visible would be nice, too! 🤗 Thankful for any tips / tricks / guides! Cheers, cosmic from Hamburg

[@EssubW]

Use the same stapling pattern that is used when stretching canvas for painting frames: kzbin.info/www/bejne/rqOxZqCtoNyXbqs If you're using burlap, mist it with water before you staple it and it will tighten a bit when it dries. I clamped my frames to the table edge to hold it still while stretching the canvas.

[@head_out]

I'm assuming you have to build two frames to do this. The fabric is stretched over one frame in the usual way, assuming the first frame will be made of small bars. Then, you have to place and secure the frame with the fabric INTO the big beautiful wooden frame, which will serve as the exterior decor and the support structure when you hang it on the wall (if you need to).

[@Dave-Rough-Diamond-Dunn]

What about the ceiling?

[@jonathanknight8251]

The ceiling cause a similar problem to the floor bounce, but usually shifted down in frequency. As do sidewalls, usually shifted up in frequency.

[@Dave-Rough-Diamond-Dunn]

@@jonathanknight8251 Yes, you're certainly right, I'm just thinking about some sort of treatment on the ceiling.

[@jonathanknight8251]

@@Dave-Rough-Diamond-Dunn That’s what I did, because after designing speakers from the ground up to eliminate the effects of floor bounce, I was left with a big hole at 50 Hz due to the ceiling reflection. The only thing that worked was a brute force approach of a broad band bass trap that has substantial absorption to about 40 Hz. It was a lot of work, but well worth the effort.

[@mohammad14382]

Great 👍🏻

[@robertvondarth1730]

In theory, if one has high ceilings, one could construct a acoustically porous floor