Beginner improvements for room acoustics; very helpful Darko video on reverb and RT60

Thanks for the link. I find Darko's reviews to be among the best out there. They're informative, witty, use comparisons and he does it all in a layman's style that makes it all relatable.  That, and his production values are up there with the best.

All the best,
Nonoise

Are RT60 times even applicable in domestic settings, smallish rooms?

Thanks for sharing!

Remember QRDDude?

They had some interesting diy diffusor panel designs.

Another site had a calculation to show how much larger the room "sounded " after using diffusor panels.

The deeper the slats the lower the diffused frequency.

Cool stuff!

Apologies that was meant for the "diffusor panels/room treatment questions" thread 

@onhwy61 I think small rooms are not helped by RT60, but Darko's room and many others are not small. I'll look for criteria regarding "small." You're raising a good point, and it would help everyone to know at what point RT60 is not applicable.

I’m pretty sure RT60 would be overkill as my apt living room is on the small side and I do listen in the near field (about 8.5’ from speakers). When I snap my fingers the sound has no trail or spark to it, like in his video comparison. Once, when Tony Minasian came over, he walked around clapping his hands and talking and said my place was fine as is.

I’m lucky in that my old apt has that awful popcorn ceiling treatment that goes some ways to ameliorate reflections up there. Throw in some artwork on the walls that must do something, and I’ve never had that reverb effect to deal with.

The one thing that piqued my interest with Darko’s video was the diffusion aspect. Due to my room layout, the right side is about a yard from a wall of large side windows with those dreadfully dated vinyl, vertical blinds. As a result, the right side of the soundstage always seemed a bit livelier than the rest and at times seemed to be a bit more forward in presentation with some CDs.

I opened the blinds at about a 45° angle, facing the speakers. With the blackout curtains behind the blinds to help absorb and not reflect off the glass pane, I played some music and, lo! the stage was now evenly uniform. How I missed this all these years makes me blush.

Minor though it is, elements of the players have shifted a bit to the right and back and it’s calmer now overall. Goes to show that even something as minor as what I did can have that kind of effect.

All the best,
Nonoise

From an acoustic perspective, any normal sized domestic room is small.  In other words in low frequencies the room is dominated by resonance modes rather than a uniform diffuse sound field.

From an acoustic perspective, any normal sized domestic room is small.

I suggest you watch the video. Darko clearly states that this is not about low frequencies. If folks watch the video, they will see why RT60 is relevant.

In most small domestic rooms it's not that big of a deal. Darko is not someone to go to for acoustic advice or really any advice IMO. If you're doing HT in a dedicated room it's a good idea because it can help get better sound field over more seats.  I've done some measurements using REW for interest only.

REW

RT60 is a measure of how long sound takes to decay by 60 dB in a space that has a diffuse soundfield, meaning a room large enough that reflections from the source reach the mic from all directions at the same level. Domestic rooms are usually too small to have anything approaching a diffuse field at low frequencies as their behaviour in that region is dominated by modal resonances. As a result RT60 is typically not meaningful in such rooms below a few hundred Hz. Use the RT60 Decay, waterfall, spectrogram and Decay plots to examine the decay of low frequencies in domestically-sized rooms.

@djones51  I'm interested to hear you say that about Darko. Your posts have always struck me as exceptionally well-informed, and I get a good impression from Darko, too. Can you tell me why you think he is generally untrustworthy or at least someone folks need not pay attention to? Thank you.

I don't think he's untrustworthy just in it for money which is fine but I take these  YouTube  guys that have a vested monetary interest with a grain of salt. the video you posted has some good advice and some lousy advice. For example when he says you can't get exceptional sound in a normal living space without room treatment from ANY speaker that's nonsense. Cardioid speakers can work very well in untreated rooms.  Wall to wall carpet with thick pad is good floor treatment. Speaker directivity and listening distance is equally important. Is a dedicated listening space optimized better? Well yes but very few people can have that. 

That’s quite the swipe you take at Darko, calling him out as being in it just for the money and denigrating his character, but then, you’ve done it here as well. At least you’re consistent.

As for floor treatment, he covered that, saying that from what he’s read, experienced firsthand, and from the experts he spoke to, floor treatment doesn’t do as much as thought. He also addressed speaker distance. Did you just get a case of the heebie-jeebies watching his video and miss some of it?

All the best,
Nonoise

Yes, he glossed over distance and yes, he gives me the heebie jeebies. 

A lot of talk about the listening room... (already some herd feeling - imitation of the idea... trend... everyone is talking about it with a serious look)...
I'll tell you this: guys, if "carpet and furniture" is not enough in your case, then this is bad news ... There are VERY few who can really professionally take the correct measurements (skills and special equipment are needed) in the listening area, and after change the room and (or) adjust the music with the help of equalizers.

@djones51 Thanks for expanding on your comments. 

My experience with both absorption and diffusion massively changed the sound of my room. I'm presently in a space with a 6.5 foot ceiling, and putting absorption on the ceiling was a game changer in terms of dealing with very harsh highs. I do have an unusually low ceiling, but I think it's true that unless one has ceilings over 9 or 10 feet (with the average, mid-field listening distance), ceiling bounce is a thing that really induces first-reflection problems. If that's right, then Darko's final piece of advice -- to at least do something about one's ceiling -- seems uncontestable.

I know that all of this advice is dependent on the many specific factors involved. For my own part, I measured with REW's impulse graphs among others, and even used the "string method" to narrow down where the first and distal reflections were coming from. Then, I treated those areas. The result is a much wider, deeper, and articulate soundstage. People who come over to listen are usually amazed at what they hear, given the visual cues of the space.

Ceiling is the one thing you can’t do in a living room.

If possible always ceiling first.

It’s obvious. It’s usually the shortest boundary (floor to ceiling) and can be the most offensive …

When building studios it’s the very first thing addressed …oven when vaulted 

it’s called “lifting the ceiling” 

There is no " one size fits all". My biggest problem with peddlers like Darko is convincing people he has the answers when he simply repeats the same old tropes. Absorb, diffuse or reflect first point? Depends. Ceiling or floor bounce good or bad? Depends. All rooms are different, all listeners are different, types of speakers matter, listening distance matters, hearing ability matters, preference matters, most of all the recording matters. Read Floyd Toole, here's an article better yet read his book. 

Ceiling is the one thing you can’t do in a living room.

Doesn't your living room have a ceiling? ;-)

@djones51 

Since when does preference matter with you measurement types?

Since when does preference matter with you measurement types?

Preference is  always important ,  unsupported claims not,  just admit it's preference not a miraculous suspension of physics.

"measurement types"

-- going in my Audiophile Glossary in the "abusive epithets" subcategory.

@hilde45 It seems like we both suffer from having low ceilings.  Mine are about 7' but in some sections are 6.5' because of soffits.  Walls and ceiling are sheetrock.  What have you used to tame ceiling reflections? 

My overall room is 14' x 24' and I've built my own bass trap panels for the front corners and absorption panels for the side wall reflection points, but still haven't addressed the ceiling and at a loss as to how and where.  Waiting on carpet install and just using area rugs right now on a concrete floor to tame the floor reflections.

Hoping your learnings can help me here.  Thanks.

@nymarty I have 703 OC panels affixed on the ceilings, pointing diagonally toward my chair in exactly the area where the ceiling first reflection occurs.