Listening room snake oil?

[FrantzM]

You're just looking for something to back up your beliefs. Sad.

I simply don't know enough to do anything different. These people do know a things or two and have papers to back their point of views. I should look into what you have written concerning sound reproduction in the home. Any links?
that would be more productive.

Peace.

 

[Yorkshire Mouth]

My own experience, and I suspect this is born out by others, is that the more large, flat, hard surfaces you have, the more annoying ‘echo/reverb’ you get. Whether that’s the correct term is really not the point. Call it a lively room. Call it what you want. A large flat hard floor with no covering sounds absolutely awful.

The more surfaces I cover, and I’ve never used professional or homemade acoustic panels, the less lively the room sounds. That’s walks and floor; I’ve never got round to putting anything on my ceiling.

Subsequently, the ‘carpet is useless’ idea is not one born out by my own experiences. But if it’s fine for others, I won’t argue.

I’ve never heard of a floor covering which completely absorbs all frequencies equally.

So you're left with the choice of a very lively room, or one where your floor doesn’t absorb frequencies equally. In exactly the same way that your walls don’t.

Each must choose for themselves.

As a general rule, I always remember the point I’ve heard made by pretty much everyone who works in speaker/room design: you wouldn’t want to listen in an anechoic chamber. Completely ‘dead’ rooms aren’t pleasant.

 

[Yorkshire Mouth]

Thick curtains and carpets can help for very reflective rooms (with flat hard surface walls and floors) to eliminate the reverb that those create. But that is only on the high frequencies, they won't fix bass or lower mid issues, that is just science. I also use a thick (felt) carpet on my old stone floor in my living room, and it does the job on those high frequencies, but i need dsp to fix my mid and bass issues...

But a real treated room is always better, and not a small ammount better. And dsp can fix a lot more than any carpet or curtain can. But it won't fix the reverb effect of the high frequencies. There, thick clothing (be it a curtain or a carpet or both) is a cheap way to get most fixed that works, and if you want it perfect, hire a qualified acoustician and keep a large ammount of money ready to fix it with an extensive rebuild of the inner side of your room. But not everybody can afford that, or has the room/space/family agreement to do that.

A very good point. ‘Echo’ (whatever) and the frequency response of the room are two different things.

A good speaker with no directionality errors should be the solution to the latter.

 

[Zapper]

One new thing I learned about was the importance of the proper floor covering fiber choice, as most listening spaces are carpeted. To my surprise I was told that pure wool is the only viable choice.

I'm quitting my engineering job, buying a farm, and breeding audiophile sheep.

P.S. would mixing in some rabbit wool make the sound more lively?

 

[DVDdoug]

I'm NOT an acoustics expert but just from "normal life experience" an empty room (like a bedroom) sounds better with carpet compared to an empty room with 6 hard-flat surfaces. It's not even comfortable to talk in an empty room with nothing to absorb sound.

 

[krabapple]

Nah. Toole came around and understood that reverberation doesn't exist in a small room.

AES Journal Forum » Reflecting on Reflections

The AES Forum is where our members get to interact with each other in between conferences and section meetings.

secure.aes.org

I'm guessing, once again, that you haven't read Toole's book (whose current edition dates from three years after this article), nor even this article you link to, which ends with him citing...his book.

Why do you keep imagining he doesn't know things he actually knows?

 

[Anton D]

Areal audio store expert could have told you what kind of wool.

 

[Justdafactsmaam]

That's not broadband absorption. Perhaps he was fooled by looking at the RT, a measurement that's invalid in small rooms. A common misunderstanding despite that it was proved otherwise decades ago.

RT is not invalid in small rooms

 

[Justdafactsmaam]

Nah. Toole came around and understood that reverberation doesn't exist in a small room.

AES Journal Forum » Reflecting on Reflections

The AES Forum is where our members get to interact with each other in between conferences and section meetings.

secure.aes.org

That is not what your reference says. Of course reverberation exists in small rooms. It’s easily measured.

If it didn’t exist why would anyone spend millions on an anechoic chamber? Just build a small room…

But most importantly will a "dense thick clipped-pile carpet on 1-inch (25 mm) felt underlay" along with a 'large wall hung Danish Rya rug over an air space" effect the frequency response in a broad matter you think? Because that would be the nature if it's truly effective. Not "even" a 2" absorber is going to be very effective below 500-600 Hz, which we know well. And air space can't be much before you have an outflow of energy where the effect of build up energy is lost.

Perhaps we should listen to actual acousticians and who are experts in the area and look at valid measurements related to a small room. Ron Sauro of NWAA labs would be one to listen to.

NWAA Labs -- Complete High-speed Speaker and Material Testing

Sure. Can you specifically point out where it says a heavy rug over a well padded under carpet is bad but a reflective floor is good?

 

[Dialectic]

If you want to read of room acoustics snake oil, check out so-called "acoustic resonators."

 

[Justdafactsmaam]

If you want to read of room acoustics snake oil, check out so-called "acoustic resonators."

I actually went to the guy’s place to hear these for myself after we had an online “disagreement” to their effectiveness.

His place in Long Beach was a great room/ loft with all brick wall boundaries. And the spaces were quasi open and divided. It had a church like acoustic.

So we are listening to his stereo and he is placing and removing these little cups from their little stands on the walls and looking at me as if I should be hearing these amazing differences.

Finally I stopped him and told him that even if these things made a difference there would be no way to hear it through the disastrous reverb of the space.

He kind of hung his head and acknowledged the space had issues.

And that was that.

 

[Punter]

I think it would be pretty pointless to apply any kind of room treatment without knowing what the room needs. There are some aspects of a room which can stand out to the casual observer, like how live it is, A simple test is to stand in the middle of the room and clap your hands, for some reason we are very sensitive to audio delay/reverb so it's easy to perceive by ear. Beyond that, you'll need to set the room up with the equipment and furnishings you want and then perform some acoustic tests. I always found it amusing that acoustic engineers will pop a balloon in a room to measure it but in an auditorium they will fire a shotgun! I think that the sheer inconvenience of engineered room treatment is what stops the average audio enthusiast from attempting to create an ideal listening environment. Most of us need the rooms in our houses to perform multiple purposes so installing absorbers, traps and so forth just isn't practical.

 

[krabapple]

Writing/saying that a thick carpet/hanging is 'broadband absorber' doesn't mean the person claims it works down to subwoofer frequencies. Something can be commonly referred to as 'broadband' without meaning 'all band'.

 

[krabapple]

If you want to read of room acoustics snake oil, check out so-called "acoustic resonators."

I'm currently arguing on a nonscience forum with a sucker who swears these work wonders in his room:

NB these are non-powered pieces of wood. They cost $1495 (per pair, I think?)*. They are claimed to moderate first reflections, and make tulips grow in your garden**.

But how, you say?

It's proprietary!

Here's a link to Shakti's white paper about them. A masterpiece of bullshittery.

https://www.shakti-innovations.com/wp-content/uploads/2017/01/Hallograph-white-paper.pdf

* currently OUT OF STOCK...there's one born every minute, as they say, must be true

**I made that part up

 

[Dialectic]

I'm currently arguing on a nonscience forum with a sucker who swears these work wonders in his room:


View attachment 354606

NB these are non-powered pieces of wood. They cost $1495 (per pair, I think?). They are claimed to moderate first reflections, and make tulips grow in your garden*.

But how, you say?

It's proprietary!

Here's a link to Shakti's white paper about them. A masterpiece of bullshittery.

https://www.shakti-innovations.com/wp-content/uploads/2017/01/Hallograph-white-paper.pdf

*I made that part up

There was a YouTube audio reviewer (now deceased, sadly) who decorated his listening room with the devices in your picture and with African masks, which, he asserted, "break up the standing waves."

 

[krabapple]

There was a YouTube audio reviewer (now deceased, sadly) who decorated his listening room with the devices in your picture and with African masks, which, he asserted, "break up the standing waves."

well, death, taxes, and consumer gullibility are the only three constants in this fallen world of ours

 

[OldHvyMec]

Well known by anymore who has experience in the field.

So you think what works in a studio works in a home environment. Do you live in a studio? I don't!
I live in a purpose built room for MY visual and listening pleasure. I posted two pairs of my speaker
in "Most beautiful speakers." Hand crafted and hand built.

What I did for a living is a lot more complex than any music room ever built. I assure YOU of that. BUT
I did fix or build most of the equipment that it takes to build a music room, if that makes you feel better
about using that equipment to make YOUR living. LOL

I made the equipment and you used the equipment, who are you Tom Cruz in "Wheels of Thunder?"
90% of the engineers I worked with SELDOM locked horns with the mechanic, I assure you, that is where
I started, not ended.

No one wants a listening room to sound anything like a studio. Ken Bassett a wonderful musician, technician,
song writer, and mixing artist has a mixing room and playback room. They are not the same or even close.
BTW he built kidney dialysis machines for the first company to introduce, peritoneal dialysis to the world.
Very prestigious credentials considering most of the instruments he plays he built with the exception to his
prize Martins.

I'm alway most impressed by those that DO for a living not measure mine, by a standard that is 75%
personally subjective along with mixing music. Music is 100% subjective or the tune of the day might
be cannon vollies timed correctly and vocals by Yoko Ono. Someone recorded that shit! Yes, No!

My point is simple, don't bad mouth what is working for almost everybody listening to music. No one cares
about 100, 50 or 25% absorption in the real world of listening. How does it sound after it's done is the
question for me. Drapes don't work and carpets don't help, sure they don't. I just saw a pig fly too.

I'll withhold my regards if you don't mind.

 

[Justdafactsmaam]

I'm currently arguing on a nonscience forum with a sucker who swears these work wonders in his room:


View attachment 354606

NB these are non-powered pieces of wood. They cost $1495 (per pair, I think?)*. They are claimed to moderate first reflections, and make tulips grow in your garden**.

But how, you say?

It's proprietary!

Here's a link to Shakti's white paper about them. A masterpiece of bullshittery.

https://www.shakti-innovations.com/wp-content/uploads/2017/01/Hallograph-white-paper.pdf

* currently OUT OF STOCK...there's one born every minute, as they say, must be true

**I made that part up

But you had me at tulips….

 

[Bjorn]

Writing/saying that a thick carpet/hanging is 'broadband absorber' doesn't mean the person claims it works down to subwoofer frequencies. Something can be commonly referred to as 'broadband' without meaning 'all band'.

Broadband in regards to control over reflections is down to the Schroeder frequency.
For a traditional absorbers that requires about a minimum of 15 cm (6") thickness. Some commercial products go lower with less depth.

Carpet, drapes, felt, etc. work primarily in the treble area and loose quickly effectiveness.

Bass absorption requires of course something entirely else.

 

[Justdafactsmaam]

Broadband in regards to control over reflections is down to the Schroeder frequency.
For a traditional absorbers that requires about a minimum of 15 cm (6") thickness. Some commercial products go lower with less depth.

Carpet, drapes, felt, etc. work primarily in the treble area and loose quickly effectiveness.

Bass absorption requires of course something entirely else.

So in a room with absorption on the other 5 room barriers that have full bandwidth absorption down to Schroeder just how much do you think the frequency response at the listener position is being skewed by the floor with a carpet and second rug both with heavy padding?

And how do you think that would compare to the increased RT 60 and the effect of the direct off axis early floor reflections?

I’d bet the reflective floor will be a much bigger problem both for amplitude and frequency response at the listener position not to mention the increase in RT 60