How NOT to set up speakers and room treatment ( Goldensound)

[Deleted member 48726]

What I have learned from this thread is that my cat apparently has a better understanding of the proper use of an acoustic panel than me.

View attachment 290420

Try a new approach; duct tape the mini tiger to one of your side walls and compare.

 

[Deleted member 48726]

Yes, of course. It's far more sophisticated than simple time gating. But both serve to get the room out of the equation.

And in my case I get good results. Maybe some rooms / systems are harder for Dirac to compute succesfully?

 

[fpitas]

And in my case I get good results. Maybe some rooms / systems are harder for Dirac to compute succesfully?

I don't know much about it. I would guess the multiple measurements help mainly at low frequencies. Time gating gets kind of useless below maybe 400Hz in my room.

 

[Curvature]

I'll just post this here: https://www.audiosciencereview.com/.../quest-for-real-bass-traps.37170/post-1309122

 

[hemiutut]

My main issue to reduce the early lateral reflections too much (high DR ratio) is that it mimics near-field. Near-field is to me quite unnatural. While you will hear the details in the recording, you are getting a brighter presentation than you would get in the small-room far-field that includes early reflections. What I know from experiments was that adding damping on the wall behind the speakers caused better dynamics but without the bad that comes with too much damping around the listening area. One effect was also that I needed to increase the volume of the amp to get the same kind of loudness, and notes/beats decayed faster. Due to the volume increase and faster decay, there was more detail heard.

This is another example that not everyone likes the same type of sound,
in my case for most recordings I prefer that extra clarity with a more muffled sound,
and at the same time something brighter and more intimate that the near field gives even when the room is treated,
because it sounds more natural to me.

In my opinion, once you have a good solid base, the nuances according to particular tastes are very diverse.
The interesting thing about this hobby is to experiment by yourself and try to adapt the sound to your personal preferences.
For a simple amateur, the time of confinement we had when the COVID helped me a lot for my tests,
although my wife would not be very happy to listen to so much sweep,
but she would not be very happy to hear so much sweep.
to hear so much sweep and pink noise.

Written with translator

Greetings

 

[hemiutut]

What? Are you saying a speaker has only one set volume/SPL level?
And therefore added reflections will always win at intelligibility, because they help increase SPL?

Of course that makes no sense at all....

SPL must be level matched, reflections vs no reflections, for any kind a valid test comparing reflections' effect on intelligibility/clarity.
Thank goodness for gain controls Lol

In the video posted by tuga you can hear more clarity when the room has panels:

In the Vicoustic VR video you hear more clarity in the sampler when the room is treated:

In the video where a person speaks in a reveberant chamber and later in the anechoic chamber,
you hear more clarity when he speaks in the anechoic chamber:

-And that will also be repeated in most cases, such as:

It is not difficult to appreciate when the voice is clearer and more intelligible.
In this case we are not talking about the taste of each one of us,
but when there is more clarity and intelligibility and I think it is quite obvious.

Do not confuse the greater SPL contribution thanks to the support of the reflections with greater clarity or intelligibility because they are two phenomena.
or intelligibility because they are two different phenomena.
One has to do with higher total energy
and the other has to do with the fact that the energy that reaches us is perceived with greater clarity even if it reaches us more sluggishly.

Written with translator

Greetings

 

[hemiutut]

What I have learned from this thread is that my cat apparently has a better understanding of the proper use of an acoustic panel than me.

View attachment 290420

Good base has with Arendal subwoofer
and the cat can not be more comfortable.

Written with translator

Greetings

 

[sweetsounds]

adding a quote from Dunn/Prothero in AES.

Take this informal study by AUGSPURGER in his AES paper, LOUDSPEAKERS IN CONTROL ROOMS AND LIVING ROOMS


View attachment 290282

As I said, the evidence to support this point of view is far and wide.

I think there is large enough data, that we need to dissect the debate into different phenomenons:
- during the recording process and in mixing, reverb even artificial reverb flatters the sound. "Wet sounds" when not overdone makes voices sound fuller, bigger, yet less pure.
- during replay early reflections 10dB or 15dB lower than the direct sound are inaudible (ie to eliminate them it needs 90% absorption).
Above that the lateral reflection increases ASW l, which some people prefer at the expense of pinpoint imaging and correct timbre.
- Others don't. I don't need more widening and prefer the accuracy. Some papers hinted that the reflection has similar characteristics to a resonance which smears the sound.

- reverbation time goes beyond first reflection. My personal experience confirms that RT60 of 0.2s to 0.45s is ideal and gives the best sonic impression to me. Longer times give me a bathroom feeling, where the music is less clear, especially on fast paced music.


Where I haven't found data is the following:
- vertical reflections ceiling/floor have a completely different frequency signature for most speakers than the direct sound. I don't like carpeted rooms, but a rug between me and the speakers gives a more intimate sonic feeling, not just for listening but also for conversations. I haven't experimented with ceilings

- second/third reflections. I actually don't mind some reflections from the back, if the wall is a couple of meters away. I don't my head to be to close to a wall though. It gives sometimes weird artefacts. In my experience it helps to cover the front wall and have not later refelectuons from the same direction as the speaker. Having said this, it gives an artificial larger depth to the sound stage.

- finally comb filtering. Yes, not directly hearable. But in my experience a lot of it give a metallic sense to music. As I have now more curtains in the room, this metallic impression is gone.
(EDIT: here is a Paper by univ. of Berlin showing thresholds of comb filtering to be around 20dB and 1ms)


In a nutshell, reflections change the sonic impression, but by far not as much as a microphone and the data analysis might suggest. Brains filter out a lot.

My personal preference is some side wall and front wall treatment, otherwise normal furniture and thick curtains.

 

[Curvature]

Inverse square law doesn't actually happen indoors because reflections reinforce the direct sound. This reinforcement doesn't happen outdoors. Therefore at a given distance indoors, all else being equal, SPL will always be higher than outdoors, improving intelligibility.

I don't think you can stretch that to intelligibility unless you are comparing it to PA situations where distance is a major issue, but the rest is true.

If reflections have similar FR to direct sound, bearing in mind that HF tend to be absorbed more by furnishing, that's where the intelligibility will come from.

It's certainly a complex interaction given the interesting dipole/omni speaker effects that rely on perceptual fusion, as do good controlled directivity speakers with their off axis response.

Personally, all the emphasis on reflection elimination is probably to do with too much reliance on basic theory of direct sound dominance, and not enough complex theory about room interactions and perception.

I found that unbalancing reflections with porous absorption created (1) hotspots in the room where because of reflection directivity you can hear very strong reflected sound that disappears if you move to a different position, (2) an unwelcome amount of clarity for midrange ringing and bass problems. The first was disorienting but can be avoided if you sit in the right spot, while the second was constantly aggravating. You could get around that if you treat every surface or design a room from scratch, but for me the best approach is to use LF panel absorption to treat SBIR and leave it at that.

I had a room treated with thick porous and panel absorbers, and it felt intimate. It had good sound, but I didn't particularly miss it after moving. All I'm really striving for these days is to fix the chewed up SBIR range issues.

Actually, since most fabric used on porous absorbers is reflective at 4-5kHz and above, I wonder if there's a good test to be done that shows unpleasant fatigue or other issues. Bare foam of course doesn't have this problem.

 

[TheZebraKilledDarwin]

I do hope you don't mean those millions of discs with lousy brickwalled, dynamically over-compressed sound... I'm sure we can trust the people making those discs.

I do hope you don't mean the disciples of Rupert Neve, the master who used Oohashi's paper to justify his claims he could improve recordings by manipulating them at 100kHz.

I do hope you don't mean the professional mastering engineers still telling us about the absolute superiority of LP sound.

Or the particular genius at EMI who thought the best way to make multichannel discs was to play the stereo versions back in the same hall they were recorded in and re-record them.

It's actually the quality of recordings that is the biggest problem with the music industry, certainly outside of the classical space, not an absolute requirement to listen only in dedicated specially treated rooms.

Toole et al for you, a professional sound for me, and everyone is happy.

 

[xaviescacs]

Here's why there's some advantage to my age compared to you kids- I have books. Not Kindle or eBooks, actual books.

xDDDD

 

[Curvature]

One of the issues with ETC is also the fact that it the spectrum of reflection is hidden in the spikes. Dr. Toole demonstrates this in a set of graphs in his books. The spikes are sensitive to high frequencies and report higher amplitude than reality. This again creates misleading situation where you chase the wrong thing.

Exactly. ETC is based on a linear calculation.

 

[Matt Bell]

Doesn't it use multiple microphone positions to analyze the room?

Yes, it requires a minimum of 5 mic positions and can compute a maximum of 13.

At least that was the case when I EQed my speakers with Dirac Live earlier this afternoon.

 

[Pudik]

Sounds like a religious experience. Do you keep an altar?

I loooove this discussion

 

[Pudik]

I will chime in.

1. Bass traps don't fix bass modes. As Dr. Toole says in one of his private presentations, "the only thing bass traps do is trap your money!" Wavelengths are way too large for any traditional velocity absorbers to do much good. Often people put a ton of them in there to get results and with it, make their room too dead. In general, few if any people are in a position to use velocity absorbers to make effective changes in their room. Pressure absorbers work better but they are expensive and require skill to design and use (they are very frequency selective).

2. He is optimizing for his eyes, not ears. Two ears and a brain don't work like a single microphone and a graph as Dr. Toole would again say. The notion that reflections are "bad" is folklore as comprehensive peer reviewed has repeatedly shown. Yet, it has become one of the "internet rules" to chase them using measurements. Doing so will lead to a completely dead room when you are done. Ask any high-end acoustician what the #1 problem with DIY acoustic is and they tell you people creating dead rooms because of this mistake.

2A. Use speakers with proper directivity and you will not need to fear reflections. Indeed, this is your #1 tool for good sound in a room.

3. Rooms are never ideal. The calculators for room modes and such for the most part generate incorrect results because your walls are not perfect reflectors. Ditto then for golden ratios, and this and that dimensions not being good. Read Dr. Toole's book for example measurements showing this. For this reason, you can actually fill nulls a bit because cancellation unlike what he claims are way away from ideal (or they would not be down just a few dB).

4. Reflectors need to be broadband. Those skyline diffusers are not. And neither are a lot of what you folks slap on walls. Minimum depth should be 4 inches.

5. DSP is extremely powerful. Get the right speakers, put them more or less where you like, and set your seating position the same. Then measure and apply DSP to pull down peaks. This is the formula which will give you 90% of the results with minimum expense and uglification factor (slapping panels everywhere in the room).

Sadly the folklore has gotten so bad that if you don't have a room full of acoustic panels, folks think something wrong with your room. What is really wrong is that people haven't spend $35 on Dr. Toole's book and a few days of reading and learning about real sound acoustics. Please, please do not follow the Internet consensus on this. They are just wrong.

I have a 16 ^2 foot room. In ur opinion, which bookshelf speakers will have good directivity? This is the 60 x 10^6 question. Thx, P.

 

[hemiutut]

I don't think you can stretch that to intelligibility unless you are comparing it to PA situations where distance is a major issue, but the rest is true.

If reflections have similar FR to direct sound, bearing in mind that HF tend to be absorbed more by furnishing, that's where the intelligibility will come from.

It's certainly a complex interaction given the interesting dipole/omni speaker effects that rely on perceptual fusion, as do good controlled directivity speakers with their off axis response.

Personally, all the emphasis on reflection elimination is probably to do with too much reliance on basic theory of direct sound dominance, and not enough complex theory about room interactions and perception.

I found that unbalancing reflections with porous absorption created (1) hotspots in the room where because of reflection directivity you can hear very strong reflected sound that disappears if you move to a different position, (2) an unwelcome amount of clarity for midrange ringing and bass problems. The first was disorienting but can be avoided if you sit in the right spot, while the second was constantly aggravating. You could get around that if you treat every surface or design a room from scratch, but for me the best approach is to use LF panel absorption to treat SBIR and leave it at that.

I had a room treated with thick porous and panel absorbers, and it felt intimate. It had good sound, but I didn't particularly miss it after moving. All I'm really striving for these days is to fix the chewed up SBIR range issues.

Actually, since most fabric used on porous absorbers is reflective at 4-5kHz and above, I wonder if there's a good test to be done that shows unpleasant fatigue or other issues. Bare foam of course doesn't have this problem.

I understand your point.

In my opinion, tuning the acoustics of our recorded signal playback rooms ends up needing some custom touch,
within reasonable margins, where no generalization of preference is possible.
Something similar happens when we attend a live concert.
We don't all like the sound of the same venues, nor do we all prefer to be at the same distance from the musicians in the same venue.


Written with translator

Greetings

 

[hemiutut]

During the debate we are having, I have been struck by a couple of points that I would like to emphasize.


1.- It seems that a large part of the advocates of lateral reflections are always beneficial,
criticize the advocates of treating them as "snake oil",
as is the case with other products sold by high-end audiophiles.

2.- Most of the defenders of point 1 argue that the aforementioned acoustic treatment is "snake oil".
is "snake oil" because of their interpretation of Toole's work,
even though not all of us interpret his writings in exactly the same way,
but Toole is not given that same possible "snake oil" treatment that we might think
he used to sell the loudspeakers and headphones he designed to fit the
headphones that he designed to fit his doctrines that are published in his studies.

In my opinion it would be partisan not to judge with the same value judgment both points,
whether in one direction or the other.
From a scientific point of view I believe that both points should be treated with the same degree of doubt.
The only thing that can resolve the issue is to test everything for oneself by eliminating bias as much as possible.
More testing for yourself, and after listening see what works for what you are looking for in your room conditions.
Theorizing is all very well to learn, but theory without practice is useless.

Conditioning a home room to sound good doesn't even require hiring a professional acoustician or buying expensive acoustical panels from a high-end store.
or buy expensive acoustic panels from a high-end store.
There is enough information available on the net so that anyone interested in acquiring the basic minimum notions
can do a custom job with excellent results for their own room.
There are forums where these professionals will help you in a disinterested way.
It would be different if it were necessary to obtain very exact acoustic values required by the client who wants to
by the client who wants to set up a recording studio, a concert hall,
or another room with very specific prerequisites.

I comment this, because I am convinced that the acoustic recommendations that many are suggesting
in this thread are largely disinterested, whose intention is not to make money with the sale of their panels.
are largely disinterested, whose intention is not to make money from the sale of their panels,
in the case of the acoustical professionals who are weighing in.

Much less am I saying that Toole or those who advocate treating early reflections
with acoustic panels are selling "snake oil".
All I am asking is that both be treated with the same yardstick so that the debate is fair.

Written with translator

Greetings

 

[tmtomh]

Here's a current shot of my listening room.

A couple of weeks ago, I replaced my B&W 705s with my father's Infinity Kappa 9s. He passed away earlier this year and I am planning on selling all of his source components and amplification gear, but those Kappas are a massive upgrade over my 705s so I had to at least try them in my space. (Edit: didn't want to get too personal, but they were also his pride and joy and so there's a lot of emotional meaning in my using them too.)

I am someone who does not want to be "enveloped" by the sound, and while I'm sure I'm hearing reflected sound whenever I listen to music, I really dislike it when I'm in a listening space and I hear sound that stands out clearly to my brain as reverb created by the room. So I greatly prefer a deader room, and I greatly prefer pinpoint imaging.

That preference guided the creation of my listening space. It's in the basement, with only one smallish window on one side near the back. The walls and ceilings all have 2 layers of 5/8" drywall with green glue between them, the floor has wall-to-wall carpet, and the entry and closet doors are solid-core. I have 6" thick, 2x4-foot absorbers behind the speakers and on the ceiling. (My father had those 9-inch quarter-round "Echo Buster" bass absorber columns, so I added them to the corners and moved the wall absorbers over slightly to accommodate them.) I have a 2" 2x4 absorber between the speakers. I have no idea if it does anything. When I remove it I feel the sound is either unchanged or the phantom center is slightly degraded. At least one of those two perceptions must be sighted bias, but either way it seems pretty clear that it does no harm that I can perceive, so I left it up.

On the back wall I don't have room for corner absorbers, so I took about 15 square feet of a couple of Ikea Billy bookshelves and put homemade absorbers in them:

These are 6" thick rockwool sheets from my local home center, wrapped in a set of jersey-fabric large pillowcases I found cheap on Amazon. Each one is friction-fit into the Billy, and it leaves a 4" air gap behind them, which to my understanding makes them a bit more effective (yes?).

But with all this absorption, after I got the Kappas up and running, I noticed that their soundstage height was much taller than the 705s - which was great! (And expected given that the 705s are small two-way stand-mounts). But the soundstage width was only a little wider than it had been with the 705s - the L and R edges rarely seemed to extend beyond about the vertical midpoint of each speaker.

So after being frustrated with that, and emboldened by @amirm 's and some others' comments in this thread, I got rid of two absorbers: I had a 2", 2x4-foot absorber, like the one between the speakers, mounted vertically at the first reflection point on each side wall. Those were mounted on standoffs, so they hung 2" off the wall, making them slightly less narrow-band than they would be otherwise (yes?).

When I removed them, the soundstage edges instantly moved to the outer edges of each speaker - so a total increase in soundstage width of about 2 feet, which I felt was significant.

The phantom center image remained rock-solid, but I thought I heard a little loss of presence in that phantom center, and maybe perhaps a slight diffusion of other parts of the soundstage. It was hard to tell because I wasn't sure if instruments were slightly less localized, or if it was just that everything seemed bigger because the Kappas throw out so much larger of an image than the 705s did - or if it was just sighted bias.

But the kicker came a day or two later, when I added a MiniDSP SHD to the system, loaded up Dirac Live, took room measurements, and created a couple of presets for the SHD. As soon as I enabled Dirac on the SHD, I put on some familiar music. As the instrumental beginning played, I was struck by how little the overall sound seemed to have changed with the room correction (except for the removal of some boominess in the 60-150Hz region). Then the vocals came in and I was shocked, because the presence of the phantom center leapt out at me. It seemed fully restored to what it had been with the sidewall panels, or maybe even a little better. I know it's not because the room-correction boosts the presence midrange frequencies - to the contrary, it cuts them. (99% sure it's not the room that's boosting the mids - the Kappas have replacement mid drivers and I think they have slightly higher sensitivity than the originals so they're a little too hot and therefore need some attenuating EQ). So I can only speculate that the increased linearity of the room-corrected output is what's responsible for that extra bit of perceived soundstage precision and presence. As always, I could be completely wrong, so I'm happy to be corrected or to hear other ideas.

Now, having seen some of the arguments as this thread has developed, I suppose that maybe technically I should not be leaving those sidewalls empty - instead, I should be replacing my old 2" sidewall absorbers with 6" or thicker sidewall absorbers so as to absorb first reflections without altering the overall frequency response of the system as much as thinner absorbers would (owing to the narrower band of frequencies thinner absorbers affect).

But such thick absorbers in that location would look terrible, would make the room feel cramped when viewed from my listening position - and most of all, would almost certainly re-shrink the perceived soundstage width, which was the problem I was trying to solve in the first place.

So I can only conclude that as a practical matter, sometimes reflections are a problem, sometimes they're not, and sometimes they're beneficial. Don't get me wrong - I think it would be insanity for me to get rid of those ceiling absorbers, and I have no desire to remove the thick absorbers at the front and back of the room.

But when it comes to those side walls, I can only conclude that the relatively short distance those reflections travel, plus the mass of the double drywall on the walls, plus whatever the Kappas' dispersion pattern/directivity must be, simply are not combining to produce major/bad/detrimental reflections.

Happy as always to see what others might think. Thanks!

 

[Axo1989]

In the video where a person speaks in a reveberant chamber and later in the anechoic chamber,
you hear more clarity when he speaks in the anechoic chamber:

This one is a great reference for the extremes of the thread. And made me laugh out loud.

Now we must quiz him about speaker cable wire resistance, to make sure we can trust him.

 

[amirm]

he used to sell the loudspeakers and headphones he designed to fit the
headphones that he designed to fit his doctrines that are published in his studies.

The bulk of research we are talking about was from Dr. Toole's time at Canadian Research Council where he was a researcher. I have quoted some of this with his position there. This is in sharp contrast with a number of companies who sell acoustic products and are very active on forums. To wit, discount was giving to our youtuber for his purchase of GIK acoustic products and mention of the same. If your antenna doesn't pick this up but are ready to make up stuff about Dr. Toole (selling headphones? Are you kidding?), then I say your compass needs alignment.