Are diffusers best for audio? 

Bless him, he has a passion for his job should be a teacher.

I find a good analogy is to think of a lamp aimed towards a wall. A flat untreated wall acoustically, is the equivalent of having a mirror on the wall, where at some position you will see a clear reflection of the lamp. An absorptive wall with an acoustic panel is the equivalent of a black velvet surface, where the light from the lamp is absorbed and you see nothing. A diffuser is the equivalent of a flat white wall where the energy is all reflected back towards you, but you don’t se an image of the lamp.

You don't need to line the walls with diffusers, you just need to position them at the reflection points. A great way to do this is with a portable mirror: if you position yourself at your primary listening point and then have someone move the mirror against the wall until the speaker is visible in the mirror, you've found the Reflection Point and that's where your bookcase or hanging tapestry or diffusion panel or absorption panel needs to go.

I can tell that your room is treated well, because your voice sounds very natural. Your voice sounds like it is coming from my room.

Love your videos, Paul! That said, I think you glossed over an important point regarding Radial Phase Grating (RPG) diffusors (yes it's spelled with an "o") by describing them as simply "fancy shmantzy". They're very specifically designed using genuine acoustic science, employing extremely complex quadratic residue equations, and every aspect from the depth and order of the channels to the width and spacing of the fins is optimized for maximum positive effect. RPG, the company, holds patents on this technology, and DIY lookalike diffusors, or bookshelves, are simply not the same thing.

i like how a company youtube channel is educative instead of just promoting their product

Paul you are right,... Any Diffusetion is probably better than none, people talking about specific frequinces is individual to each person's room and system.. Basically less echo is probably going to make the sound more discernable /understanderble... Keep em coming Paul. Regards Antony Warrington England..

Various books also have varying densities. Hard back, paper back, ring bound manuals, etc. I'm thinking of a bookshelf unit that has a rockwool cavity back covered in fabric (just an inch or two deep).

Between 0:18 - 0:20 an input either in your wireless mic receiver or in your camera is overloaded.

I will give Paul one thing . . . he is patient and diffuses aggressiveness with humor. I don't know if I would be so magnanimous in continuing to answer questions that are confrontational -- not to say that such questions may not be warranted . . . it just seems that both Paul and the RU-vid audience should constrain their interaction to the subject at hand rather than many of the tangents that come up along the way. Speaking of diffusers . . . furniture, drapes, area rugs, al manner of angles in the room from accessories work for me.

This man’s like the bob ross of audio

Having been through some education on room treatment I do not understand the statement that one type of object is the end all best for room treatment. Diffusers, absorbers, bass traps, etc. all good, but not any one of them is "the best thing for room treatment". There is no magic bullet, one size fits all solution. One can't just stick diffusers in a room and call it done. It all depends on the room's need as to what is to be used to treat it. Some rooms need diffusers and some may not need diffusers, but rather something else instead. Just like one can over-treat a room, using the wrong items in the wrong way will bring unwanted results. The best thing to do is experiment with what is on hand first and find the trouble spots. Then get with an acoustical engineer and go over things. Sometimes some money can be saved by what is already in a room before going out and buying room treatment. Room treatment works and doesn't have to be super expensive if done correctly. More often than not you may only need a couple of pieces or maybe 3 or 4 at worst. People who want to sell you 12 piece kits or tell you that you need a ton of treatment don't know what they are talking about.

Bookshelf + thrift store books = a fantastic diffuser. It also provides a conversation starter, as well as, something for the bored "tag along" to engage with to keep themselves occupied rather than fiddling with your gear.

Thank you very much about your valuable teaching.

Great to see that you also mention books... I was on another site and the person talked about that idea as being not practical... and funny enough you have people like Reid Shippen who has 4 or 6 walls covered in books!

Books, cloth upholstered sofas are good sound diffusers and absorbers. I rely on them all the time.

Every day I learn something from you, sound is so fascinating , thanks.

It's definitely harder to overly treat a room to the point of sounding dead. If your dealing with hard floors and natural reverb problems go with thick rugs or carpet. Build a diffuser that's of appropriate size for your room. The bigger the better. Buy some absorber sound panels. They really aren't that expensive. Just do a little at a time when you can. The small changes you make over time will add up and the room will improve. Most of the time it's hard to tell with just one or two upgrades. Treat your room and improve gear when you can. It's kinda like building a race car. All those little upgrades that didn't yield an obvious difference on their own will add up as a better overall package. It's a journey take your time and learn as much as you can. Try to have some fun along the way.

Great video, and a helpful follow-up to this could be where to place diffusers in a room aside from the normal first reflection point.

Please don't suggest that bookcases are anywhere near as effective as a real diffuser. A book case will do some odd scattering but nothing compared to real diffusion. Those diffusers are very carefully calculated out. If you cover a single slat, the entire thing will stop working because it all works as a system with phase grating. It's not simply making the sound bounce off of a certain point.

Are used your bookshelf method in my work studio out of necessity for all the electronics books binders folders equipment in boxes of supplies from the front of the room to the back of the room it’s not pretty for some but it works excellent. before the shelves no music ever sound natural or good.

That was a great tip!! Thank you very much!!

Would you recommend absorption behind speakers and diffusers elsewhere?

I agree that diffusion, when properly implemented, can significantly improve the experience. However, diffusers in this video are too narrow and will not diffuse low frequencies which will create an unbalanced result. Frankly, I do not know how can someone be serious about acoustic treatment without addressing issues around low frequency. BTW, the seats in the video are too close to the wall for diffusion. Also, while properly design bass traps do absorb reflected energy, they will actually raise the volume at the frequencies subject to a null (e.g. dip in volume due due to cancellation from reflected wave).

I can send you a truckload of books for your new studio/listening room! Moving soon from a house I have lived in for 35 years. Too many books to move to my next house.

Terrific teaching and explanation sir!

How high should diffusers and absorption be located? I see a lot of listening rooms with them mounted high or mid wall., with the lower 2 or 3 feet of wall untreated. Shouldn’t they be located lower towards the seating position and at ear level?

Dead rooms remind me of being up in the alpine conditions of Colorado. Very little air to transport sound. Almost vacuous.

Can you do a video on all the treatment in that room

Paul why are you so awesome?

I'm not sure I think, a thin coaching of absorption material like natural wool fleece 3-mm thick that allows sound waves to pass through and bounce back is a more natural approach giving you that sense of Hall having the fleece at different distances to the wall with overlapping gaps and on the Ceiling in a wave using stick-on hooks and fishing line a little nail or dowel through the material going right behind the speakers in a natural Curve to the wall and about 2 to 3 feet in front of your speakers on the Ceiling. as I say this would be done in sections so there's a gap between the layers not just one piece so the sound can go in and bounce out giving it delay and even some gaps in between the layers 6" near the speakers working away getting bigger 8 feet away 12" hard surface they should be in sight of the tweeter only if a small range mid driver4" that can be partly included in the gap, make sure the tweeter is totally in the gap. in the front area of the speaker extending a couple of feet in front and 2- 3 feet behind nothing needs to be in place until the Sitting position what would be between 7 to 9' extending a couple of feet in front and a couple feet behind. In staggered layers strips. If you had wooden blocks you can drill holes split the Block put them in a straight line so wooden dowel can be rested for two provisions in the block so there's an overlap 3" gap between the two dowel positions and inch and a half from the wall should be fine. There's nothing permanent only the blocks what could be be stuck on with good quality tape pads or liquid nails

*Me when I first seen a quadratic diffuser* 4:38

Moving into a house with a large finished basement, so for the first time I have an opportunity to have a dedicated listening room. Right now the basement has a drop ceiling with old office style ceiling tiles. Any suggestions for what type of ceiling tile to buy? I am afraid of buying something that sounds very dead, and there is already carpet in the room. I think I need something to liven it up?

I'm surprised all the baffles/slats are all the same angles, rather than say angled to force waves in. Do you place absorbing material at the backs of each of those "chambers" between the slats?

If you want to hear how the music is recorded then you should have dampenig in the front of the room to take care of first reflections, then behind that line diffusers and other treatment can be placed. Very strange that you don't think dampening is on of the most important thing, because the room is reflective the opposite is damping to get the room to disappear. Only typical cable-audiophiles would want their front end of the room to be reflective/livefull because that's the only thing they have heard.

I think it's counterintuitive to audiophiles to want a compromise between an anechoic and echoic room. We want the optimum, which is a middle ground compromise. Hard to process.

Can you put diffusers on the high part of the back wall if you mic is at the front of the room? OR do they have to go on the mid part of the back wall?

Dennis at AcousticFields has a great RU-vid channel all about room acoustics

Not the fact that the room is dead in a chamber. The difference is..the room is so insolated that you hear no sound from outside of the room also..because its so insulated you soon hear very low level sounds.

And what happen if instead of a diffuser you use absorbing material that have the same shape as this diffuser? Will some of the sound hitting the absorber be reflected without directional cues, doing the exact same thing as a diffuser while reducing the echo in the room?

Good video by Steve today. Shows how's its ok to be free in America.

Good tip thank you

Can we make the floor acoustically diffusing?

I watched another video on here thar showed books don't work. So confused right now :/

jast that you know diffuser also absorb some of the sound ... I love!!! what diffuosers can do to the sound

What else would they be used for?

Who knew there were so many experts

Are diffusers good if you have a small office with reverb and only do podcast recordings? I have seen some top podcasters with diffusers located behind them.

How to keep those diffusers clean? Bugs and spiders will love all those niches! I don´t want to open a bug´s hotel in my living room.

Great Paul! Except I disagree that diffused sound is then ignored by your brain. Actually, the "noise" helps improve resolution. See Stochastic Resonance. en.wikipedia.org/wiki/Stochastic_resonance

What are the soft-looking panels above the diffuser?Are those any good at absorbing unwanted sound?

9 guys were at it again

did he mentioned speaker wires that affect stereo width? Hope no.

How are plants as diffusers?

Did you have a couple before that talk?

LP's are pretty good at doing that.

My question would then be: Why not kill every reflection and simulate the diffused reverberations in post with a good vst plugin?

lmao........"Sound comes back from the diffuser (if any), ears go, I don't know what that is". Hilariously true.

Did you ever pull one of those books down and read it? I love reading almost as much as I enjoy listening to music, but, as with all things, there can be a huge variance in quality. While their are recordings and books that I go to time and time again, some books aren't worth the paper they're printed on and are unreadable. Perhaps you've found their purpose: sound diffusion.

Well I’m sorry I have to disagree with your explanation of reflections. Reflections are good they just need to be controlled reflections. You want a 1 to 1.5 millisecond delay time. Echos need to be addressed and they happen when you have parallel surfaces common to most sound room. But before any acoustical treatment I recommend you perfect speaker placement. You CANNOT position speakers with acoustical treatment in the room at time of tuning. In fact you will find that when speaker position is correct both for the best bass response you will notice you hear less if not no room reflection issues. Then when you have speaker placement perfected you can logically and strategically place the right acoustical treatment. Defusion is best because it does not absorb sound but scatters sound waves that are reflected back to the parallel surface adjacent to that surface. Some slight and light absorption material might help only on the back wall behind the listener. But this material must be light as to not absorb but more to delay the sound waves. The issue with absorption is it’s not linear it creates comb filtering issues which make it worse. Meaning it will absorb at certain frequency’s and reflect at others. So very careful care must be taken when using any absorption material. Use your voice as a tool so it sounds natural and has good articulation. There is much poor and wrong advice on acoustics and Paul gets it right when he says you want a room that sounds natural and has good controlled reflections

Books okay, but records are probably better. :^) _Decent_ books and a proper bookshelf are probably going to be more expensive than proper diffusers, though. Just pay the guys?

Aaaaaahhhhhh! My EARS! THE CLIPPING! For crying out loud, put a compressor on that mic! 🙀

Cheap to build. But expensive to buy, that's why nobody has them, or they dont have enough, or the wrong kind.

Please accept the Ethan Winer debate invitation!

In a live show..you hear the room as well as the front speakers..the room lets you know the size of the room and the audience..IM not agreeing that diffusers are the answer. Matter of fact . ILL BOLDLY STATE ITS WRONG..but theyre stuck..they are forced into telling this fib..and if I tell the answer. Soon theyll be doing it and ill be just as broke and old and concidered.. ignorant..but i assure you..theres a better way than destroying information..

You know getting married is a bad idea when "marital harmony" is disrupted because of the introduction of diffusers.

💪💪💪💪💪🙏

What about the Oval Office? Hmmmmm.

Wow, Paul! Your mic-level is still WAY too hot. Lots of CLIPPING! Give yourself some headroom. We're not in fighting in the Loudness Wars, here!

Echo flutter is a nasty bitch. Diffusers are incredibly necessary . I recommend the prime acoustics London 10 panel kit for whomever needs room treatment. You'll treat your live end and dead end extremely well.

Imagine having a channel about audio and being normalized at -2.7dB in RU-vid. (stats for nerds)