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

[Deleted member 48726]

Yes. EQing with all the reflections included is a ticket to sonic disaster

You're kidding.. Right?

Well I digress. I'm quite happy with my "sonic disaster" Dirac profile..

 

[fpitas]

You're kidding.. Right?

Well I digress. I'm quite happy with my "sonic disaster" Dirac profile..

I've had very bad luck trying to EQ based on ungated measurements. Dirac does ungated correction?

 

[Deleted member 48726]

I've had very bad luck trying to EQ based on ungated measurements. Dirac does ungated correction?

Don't know. Does anyone know exactly how Dirac Live does its corrections?

 

[thewas]

Dr.Toole defends that if a box does not measure according to what he considers is a good measurement for him, what you have to do is to buy a better one.

Yes, you can also read it in the first link in my signature.

Dr. Toole himself recommends not to equalize loudspeakers above 500hz,
because he says that the directivity problems are not corrected after that

Yes, but again especially the early directivity (index) of the Edifier isn't too bad as I showed above.

The Edifier R1280T prior to equalization had a score of 4.6, the worst of those tested,
but after EQ they were only 2 tenths below the Neumann KH80.
And it is likely that the on-axis response could have been tuned a bit more with some more subtle EQ tweaks.

Exactly, this is a result of its decent directivity, if the directivity would have been really poor the score difference would remain larger.

 

[fpitas]

Don't know. Does anyone know exactly how Dirac Live does its corrections?

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

 

[Deleted member 48726]

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

Yes.

 

[fpitas]

Yes.

Uhm...

 

[Cote Dazur]

But at the same time, this is almost the opposite of the cable discussion, which I find a bit funny:
Cable discussion:
Person 1: You can see from the measurements that it can't have any difference at all, you have to believe the readings, your subjective feeling is deceiving you.
Person 2: But I do subjectively hear a difference, so I don't believe you and your measurements. There is certainly a lot that you can't measure.

Room acoustics discussion:
Person 2: You can see from the measured values that there are huge improvements when I use absorbers.
Person 1: But the measurements are deceptive, your brain works differently than a microphone, you can't trust the measurements.

Thank you for this clever observation, very true and funny. One might add that at the end of the day, cable is a perfect example of "snake oil", as the measurements are clear and the scientific conclusion is understandable by most.
Small room acoustic reflection as it relates to stereo imaging is a completely different animal. We can easily measure huge difference in reflection using treatment and the scientific conclusions are not obvious to most.
Measuring stereo image is not done yet. All the scientific conclusions about what is best for stereo imaging are based on extrapolations on measuring anything and everything but the stereo image, even measuring transducer looks like a piece a cake compare to what would need to happen to measure stereo imaging.
As mentioned, comparing cables (or DAC, amplifier, etc....) by listening blind, is super easy,
Comparing, by listening blind, the same room and set up with and without various degree of room treatment to alter reflection is close to impossible and at least does not seem to be done, was not shown once in this thread as proof for either point of view.
We have seen measurements showing differences, but the jury is still out on how exactly that correlate to what eventually reaches our brain.
To me, room treatment, is the opposite of snake oil, as usually exemplify by cables, power filters, etc... all of those have zero effect on what reaches our ears and brain.
The room and its optimization has a huge impact (possibly the biggest impact) on what we hear, making it polar opposite to snake oil. With great power comes great responsibility, that the whole field appears to me as the less scientifically proven of all audio aspect, should alert us that the peddlers will be more difficult to detect, but not that it is a subject we should deemed irrelevant, as we can for the usual snake oil component.

 

[Thomas_A]

If we move the speakers, we also will likely change the frequency response. In some cases, and unless the room is heavily treated, the response can change considerable in the lows due to SBIR. So one might end with comparing something else as well.

The highlighted part here is very true. Manfred Schroeder's study on the best concert halls revealed that they had lateral reflections arriving between approximately 20-25 ms after the direct sound in common (shoe box halls). In our small listening spaces, they arrive anywhere between 2 ms and 10 ms in most cases. Psychoacoustically that's very different.

Late arriving reflections should either be partially reflective or preferable diffused. They shouldn't be absorbed.

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.

 

[gnarly]

It's actually not the HF roll off that's the issue here but the loss of mid band frequency hearing. An audiogram will tell you how much you have lost. On iOS a free app called mimi hearing test is comprehensive enough.

Yep. I may have some mid band loss too...who knows, and must admit don't really care.

I'm confident age related hearing changes are pretty inconsequential when it comes to the clarity increase I hear with outdoor listening..
Like i said, the clarity improvement is not subtle...and I've heard it over several decades now.

I really look forward to the beginning of each spring/summer when I set up gear outdoors.
It's always a recurring ear opener.

This last winter I worked on perfecting my three channel LCR setup for enhanced stereo. It uses 3 identical speaker stacks, so the center channel is the same as L&R and allows LCR matrixing for playing with imaging and spaciousness, etc.
I was thinking I finally had indoor sound converging on the clarity i hear outdoors.
Until....I set up one of the stacks outdoors a month or two ago......
....and once again, the clarity improvement of outdoors (aka reduced reflections) was plain as day

Well, there's always a little letdown realizing how much indoor suffers ....but I look at like this....
The clarity I hear outdoors, becomes the goal to strive for indoors...
And that I wouldn't even know what to fully strive for, if I hadn't heard it outdoors...

 

[MattHooper]

managed? - you put springs and rocks under your speakers - what did that manage?...

LOL.

Points for the honest screen name

 

[gnarly]

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.

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

 

[tmtomh]

Uhm...

Because I am willing to look dumb if it helps me learn, I’ll go ahead and ask: like @Holdt , I’ve used Dirac and it seems to work well, including at higher frequencies.

So is the idea here that by requiring the user to take multiple measurements from different locations (9-17, but most typically 13), Dirac collects data enabling it to EQ the higher frequencies based on quasi-anechoic measurements, or at least based on some info about reflections based on the differential readings obtained from the various measurement locations?

 

[fpitas]

Because I am willing to look dumb if it helps me learn, I’ll go ahead and ask: like @Holdt , I’ve used Dirac and it seems to work well, including at higher frequencies.

So is the idea here that by requiring the user to take multiple measurements from different locations (9-17, but most typically 13), Dirac collects data enabling it to EQ the higher frequencies based on quasi-anechoic measurements, or at least based on some info about reflections based on the differential readings obtained from the various measurement locations?

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

 

[TheZebraKilledDarwin]

I agree that it is very difficult to evaluate room acoustics products before buying and make a rational decision about what is useful and helpful. There are often measured values, but ultimately it comes down to who you trust. Because the products are so big and bulky, because you have to mount them first, etc., you can't easily compare different products, there are almost no helpful reviews, etc. And even if there are measured values, you still don't know how well the changes do to your subjective feeling. Here in the thread was pointed out that these products can have harmful consequences as well.

But at the same time, this is almost the opposite of the cable discussion, which I find a bit funny:
Cable discussion:
Person 1: You can see from the measurements that it can't have any difference at all, you have to believe the readings, your subjective feeling is deceiving you.
Person 2: But I do subjectively hear a difference, so I don't believe you and your measurements. There is certainly a lot that you can't measure.

Room acoustics discussion:
Person 2: You can see from the measured values that there are huge improvements when I use absorbers.
Person 1: But the measurements are deceptive, your brain works differently than a microphone, you can't trust the measurements.

I just noticed this when you said that room acoustics are "the new snake oil". In both cases there are perceived differences between subjectice and objective measures, so it can be hard to find commen ground when it comes to evaluating these products. But at the same time, the situation is very different.

A good practice to avoid snake oil salesman: Learn from the professionals, that are earning a living in the field. They have to use tools and equipment that works.
Well, before someone chimes in and claims, that academics also were earning their money by studying the field : I mean sound engineers PRACTICING empirical knowledge in the complex real world. Acousticians building successful studios. The ones that make the mixes and sell millions of records know, what is important and what not. Ask them, learn from them and avoid the theoretical experts.

 

[NTK]

Oh very cool thank you.

But it looks to me HRTF is what the ear/brain processing is doing..
Looks to me it's about creating an inversion of the ear mics capture, as shown per snip below.
Seems to me that inverse frequency response leveling reflects it what takes to make things sound right, .....no?

View attachment 290298

Dr. Griesinger's method is that, for a highly accurate reproduction with headphones, he records the sound waves at his eardrums, and then reproduces it with headphones such that the reproduced sound waves at his eardrums are as close as possible to the ones he recorded.

Since the headphones are outside the ears, the sound waves they produce will be spectrally altered by the pinnae and ear canals before they reach the eardrums. That's why the headphones need to be EQ'd to remove this spectral modifications so that the reproduced sound waves at the eardrums are the same as those recorded. He did it by putting on his probe mics and wearing the headphones over them, and measured the headphones to eardrums transfer functions. His headphones EQs were the inverse of the headphone to eardrums transfer functions. With these EQs applied, when replaying the recordings made with the probe mics, the sound waves arriving at his eardrums would be as close as possible to the ones he recorded.

I wouldn't consider the spectral modifications from the headphones to the eardrums as "ear/brain processing". The brain is definitely not involved, and the spectral modifications is by a purely passive process due to human anatomy. I'd consider "ear/brain processing" something akin to the precedence effect.

For a demonstration of how strong the precedence effect can be, you can listen to the clip (with loudspeakers) in this post.

A Little Demo of the Franssen Effect (Precedence Effect)

The Franssen effect is an illusion due to the "law of the first wavefront" (aka precedence effect). When both of our ears receive coherent sounds, we lock on to its first few milliseconds (the first wavefront) to determine its direction, and our brains "fix" the sound to this direction. Our...

www.audiosciencereview.com

 

[hemiutut]

If we move the speakers, we also will likely change the frequency response. In some cases, and unless the room is heavily treated, the response can change considerable in the lows due to SBIR. So one might end with comparing something else as well.

The highlighted part here is very true. Manfred Schroeder's study on the best concert halls revealed that they had lateral reflections arriving between approximately 20-25 ms after the direct sound in common (shoe box halls). In our small listening spaces, they arrive anywhere between 2 ms and 10 ms in most cases. Psychoacoustically that's very different.

Late arriving reflections should either be partially reflective or preferable diffused. They shouldn't be absorbed.

Exactly björn,the problem is that if there is a certain reflected energy that arrives so little delayed
and is still so intense with respect to the sound that comes directly to us is when everything is destroyed,
especially in rooms that are not very large and are intended for the reproduction of recorded signals
which already have certain spatial cues integrated so that a 3D space is recreated from two emission sources.


The problem is even greater when the home playback room is small.
In Europe, many rooms or lounges range from 12 to 25 square meters (12 to 25 square meters).
If you leave the side reflections untreated, chaos is guaranteed.
In the smallest of the rooms mentioned above, it is impossible to delay the delayed energy sufficiently
to delay the delayed energy sufficiently to take advantage of the late reflections without causing chaos.
It is true that it is somewhat helpful not to treat all the walls as if they were almost anechoic,
but it is necessary to use absorber in a large part of them supported with another between intersections between walls and wall centers.
And if it remains after it something dead for the particular taste, we can always intercalate some superimposed strips
on the absorber as a deflector in some areas to achieve the balance that everyone wants to obtain.

In larger rooms you can have more play.
So in my opinion generalizing the same strategy as the only valid for all rooms is a big mistake.

Written with translator

Greetings

 

[Galliardist]

The ones that make the mixes and sell millions of records know, what is important and what not.

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.

 

[tmtomh]

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

Thanks!

 

[Svend P]

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.