The BEST rooms - looking for real world measurements

[holdingpants01]

I was wondering if anyone ever saw any room measurements (done with a microphone, you know, basic sweep) of either some good mastering studios, or just the best room you know of. I'm interested in not smoothed too much frequency response and spectrogram of the low end. I'm looking for some references, reality check, goals, what is actually possible in a room proven by measurements. I'm not looking for guidelines or simulations of what room correction "should" do, I would like to see pure data.

 

[holdingpants01]

I've found an article by Bob Katz with some helpful graphs, I just don't know how smoothed it is https://www.stereophile.com/content/katzs-corner-episode-17-perfecting-perfection but still it's interesting to see how it looks without room correction

 

[ob1]

I am sorry, for I know it is not exactly what you were looking for, but I found the following article from Mitchco enlightening. Knowing the ideal could you give you an idea what to strive for.

Real world, yes.
With and without correction, yes.
Reference studio or best room, no.

What is Accurate Sound?

I see this question asked often on audio forums and there are many varying answers depending on one’s viewpoint. Viewpoints range from being able to recreate the performance, to its just entertainment folks, and everything in between. For this article, the context for what is accurate sound is th...

audiophilestyle.com

Moreover, I like the idea behind Michtco's book, since he advocates that one can get very close to a perfect room with dsp. Very high praise to Acourate, it has changed how I envision hifi and I like the idea behind the software IACC measured coefficient, which in my words, is a metric of how closely the channels are matched.

I have read a few criticism of this very idea here, but I am not proficient enough to give any insight. However, anecdotally, I have seen a correlation of high IACC score and perceived quality of reproduction.

PS Katz's graph was taken in Acourate...

 

[holdingpants01]

I am sorry, for I know it is not exactly what you were looking for, but I found the following article from Mitchco enlightening. Knowing the ideal could you give you an idea what to strive for.

Real world, yes.
With and without correction, yes.
Reference studio or best room, no.

What is Accurate Sound?

I see this question asked often on audio forums and there are many varying answers depending on one’s viewpoint. Viewpoints range from being able to recreate the performance, to its just entertainment folks, and everything in between. For this article, the context for what is accurate sound is th...

audiophilestyle.com

Moreover, I like the idea behind Michtco's book, since he advocates that one can get very close to a perfect room with dsp. Very high praise to Acourate, it has changed how I envision hifi and I like the idea behind the software IACC measured coefficient, which in my words, is a metric of how closely the channels are matched.

I have read a few criticism of this very idea here, but I am not proficient enough to give any insight. However, anecdotally, I have seen a correlation of high IACC score and perceived quality of reproduction.

PS Katz's graph was taken in Acourate...

Thank you! Kind of what I'm looking for, though the room and speakers doesn't look that special and most importantly the "after" examples are a simulation, not measurements. I wanted to see how close to flat line the real room response can get in the best case scenario but measured, not predicted or simulated. I also feel the Bob Katz example is simulated, but I don't know this software and it's not clear from the article. Same thing with all the Trinnov examples I've found, no one ever shows how the room measure after the calibration.

 

[MaxwellsEq]

Sound on Sound have an article about Control Room Design which covers many of the approaches used and some measurements from studio control rooms.

It's worth remembering that the monitors are tools to get a job done. Also that most domestic listening environments don't have a massive mixing console in the middle of the room. Also, the main monitors are frequently flush-mounted.

 

[holdingpants01]

Sound on Sound have an article about Control Room Design which covers many of the approaches used and some measurements from studio control rooms.

It's worth remembering that the monitors are tools to get a job done. Also that most domestic listening environments don't have a massive mixing console in the middle of the room. Also, the main monitors are frequently flush-mounted.

Thanks but I'm not sure how's that relevant, I'm looking for real world examples of measurements of exceptional sounding rooms, not some basic guidelines for control rooms without meaningful measurements. All they show on graphs is how removal of first reflections will look like, but I question this approach anyway. BTW I have a control room without mixing console as those are mostly useless, especially for mixing ITB and mastering

 

[MaxwellsEq]

Thanks but I'm not sure how's that relevant, I'm looking for real world examples of measurements of exceptional sounding rooms, not some basic guidelines for control rooms without meaningful measurements. All they show on graphs is how removal of first reflections will look like, but I question this approach anyway. BTW I have a control room without mixing console as those are mostly useless, especially for mixing ITB and mastering

Sorry I disappointed you.

 

[jlo]

I was wondering if anyone ever saw any room measurements (done with a microphone, you know, basic sweep) of either some good mastering studios, or just the best room you know of. I'm interested in not smoothed too much frequency response and spectrogram of the low end. I'm looking for some references, reality check, goals, what is actually possible in a room proven by measurements. I'm not looking for guidelines or simulations of what room correction "should" do, I would like to see pure data.

Hi,
have a look at Igor's room here, mainly used for his professional recording use : measurements are well detailed.

 

[dualazmak]

My latest system setup of DSP-based multichannel multi-SP-driver multi-amplifier fully active stereo audio project would be of your reference including the best tuned Fq response at listening position measured by "cumulative white noise averaging method (ref. here and here)", photos of listening room and all the gears.

 

[ozzy9832001]

Thanks but I'm not sure how's that relevant, I'm looking for real world examples of measurements of exceptional sounding rooms, not some basic guidelines for control rooms without meaningful measurements. All they show on graphs is how removal of first reflections will look like, but I question this approach anyway. BTW I have a control room without mixing console as those are mostly useless, especially for mixing ITB and mastering

Every room, even ones built specific for the purpose of listening critically to music are going to have challenges. There will always be reflections. You say you challenge the removal of first point reflections? Why? What draws you to this conclusion?

The flattest response you can get will be the best for critical listening like mixing. How flat the response goes depends on the room, speakers, room treatments and your position. That's all.

 

[holdingpants01]

Every room, even ones built specific for the purpose of listening critically to music are going to have challenges. There will always be reflections. You say you challenge the removal of first point reflections? Why? What draws you to this conclusion?

The flattest response you can get will be the best for critical listening like mixing. How flat the response goes depends on the room, speakers, room treatments and your position. That's all.

Cool, but can you show me some measurements of flattest response room you ever saw? That's all I'm interested in, in this thread

 

[ernestcarl]

Cool, but can you show me some measurements of flattest response room you ever saw? That's all I'm interested in, in this thread

Are you talking about the "flattest", yet un-equalized speaker room response with the actual data to scrutinize? Because... that's likely not gonna happen.

I could show you mine, but some compensation (e.g. EQ, bass management, and considerable positioning compromises) were absolutely necessary to get it to something "reasonably flattish".

 

[ozzy9832001]

Cool, but can you show me some measurements of flattest response room you ever saw? That's all I'm interested in, in this thread

No, because the room is only part of the equation.

Companies spend millions on developing their professional rooms. The data isn't necessarily available for a number of reasons. Plenty of people on these forums have responses that are +/-2 dB (which is insane).

And in your original post you state you want to know what's possible.

What's possible depends on many factors.

Even anechoic chambers speakers don't have a completely flat response -- there are still natural rises and falls in the frequency response, the key is how far down they go. In a decent room +/- 3dB I'd say is good. +/-2 is great. +/-1 is probably near impossible for most people. Hell in my room I'll take +/- 4dB.

I'm really not sure exactly what your looking for. Most people don't post about their flat response because honestly most people don't care.

If your looking to improve your room then you might want to post your frequency response so it can be evaluated.

 

[dualazmak]

Cool, but can you show me some measurements of flattest response room you ever saw? That's all I'm interested in, in this thread

I still do not understand what would be your intention/motivation. By "some measurements of flattest response room", do you mean professional anechoic measurement chamber room, or some recording/mixing studio room, or our home listening room, or home theater room ???

And you would please be reminded about the two different types of Fq response measurement methods; popular "rapid sine sweep" (with much smoothing) and "cumulative (recorded) white noise averaging" (without typical smoothing but FFT size as smoothing factor). The two methods not always give similar/identical Fq response curves; each of them has pros and cons. My very recent post here and here would be of your reference, I assume.

As briefly shared in my post #9 above, let me show you Fq response of my system and room air sound in my listening room acoustics measured at my listening position (for the details of the latest system setup, please refer here); all measurements were done by using "cumulative (recorded) white noise averaging (ref. here and here)".

and,

Please note that the fine up-and-down structure of the room sound total Fq-response curve (yellow Fq curve) is not statistical fluctuations, but they exactly represent/reflect room acoustics (reflections, resonances, mutual compensations, etc.) thanks to the "cumulative (recorded) white noise averaging" method. My listening room is not symmetrical in L-R, Up-Down, not symmetrical in furniture alignments, and of course not anechoic (please refer here).

The fine structure of the yellow line (total Fq response) is highly reproducible in multiple/repeated measurements (see below attached color-3D sound spectrum chart) , and I do not like, therefore, applying too much smoothing (especially psychoacoustic smoothing) to it which completely hide/ignore the fine room acoustic representations especially in midrange - high Fq zones (ca. 500 Hz - 20 kHz).
Just for your reference, the typical 3D-color spectrum (by Adobe Audition 3.0.1) of the cumulated (recorded) white noise; the horizontal stripe-microstructure of each recording bar corresponds to the details of the room acoustics.

Consequently, the way of presentation of Fq response curve(s) should greatly and inevitably vary depending on "what we would like to know/show" from/by the curves.

 

[Curvature]

I think the best I have seen is by @sarumbear.

Pro studios don't post many measurements. Which is a shame for a lot of reasons.

 

[ernestcarl]

I think the best I have seen is by @sarumbear.

Pro studios don't post many measurements. Which is a shame for a lot of reasons.

They sometimes do, but not always the final “finished” stage or the scaling and smoothing is difficult to compare with others — say, a Dirac or Sonarworks graph.

I found a bunch of REW measurements (maybe more than two dozen — probably mostly home studios) from gearspace, but the quality is very much all over the place.

 

[holdingpants01]

I'm just looking for as flat/good rooms as possible with proper measurements, I'm just curious how flat the in room response can get, for reference

 

[ernestcarl]

I'm just looking for as flat/good rooms as possible with proper measurements, I'm just curious how flat the in room response can get, for reference

For a start, you can view jim1961's "exceptional" measured listening room data over at the gearspace forums here:

Gearspace.com - View Single Post - My Listening Room

Post 12239385 -Forum for professional and amateur recording engineers to share techniques and advice.

gearspace.com

Yeah, it's rather old (2016 the latest) -- but still one of the "better" seen and thoroughly documented -- with REW (data file for download) results in gearspace/"gearslutz" of a meticulously purpose-built listening room with many pages worth of discussion.

I have to say that I also upmix stereo sources to surround often, but minus the very elaborate acoustic panelling as seen in jim's room.

The amount of "combing" seen below is something that I haven't noticed in my own surround "upmixed" measurements. However, the MCH mixing algorithm, placement of speakers, and magnitude attenuation levels are not the same. In fact, there's hardly any difference in the magnitude response when the surrounds are completely muted in mine.

Some more detailed graphs of his left channel only:

 

[dualazmak]

I'm just looking for as flat/good rooms as possible with proper measurements, I'm just curious how flat the in room response can get, for reference

You would please understand that, other than the very fine/small up-down structures of my total room Fq response, I can very easily (even on-the-fly while listening to music) make the total Fq response almost completely flat over 20 Hz - 22 kHz by using gain/volume controller of the four amplifiers driving directly dedicatedly the woofers, midrange-squawkers, tweeters and super-tweeters, (while keeping the subwoofer gain constant), in my so-far-well-acoustically-treated listening room.

I just do not like (out of my preference), however, such an almost flat Fq response total sound in my audio system (and room); my best tuned room Fq curve shown in my above post #14 was "so tuned" to be best fit for my best personal preference and my music preference with slightly downward tendency over 40 Hz to 4 kHz, and slightly upward tendency over 7 kHz to 20 kHz (which is variably compensating age-dependent hearing decline in the high Fq sound).

 

[dualazmak]

Thank you so much, @ernestcarl,

It is really impressive (and a kind of my surprise) that "the total tendency" of his (jim1961's) best tuned Fq response and REW-Wavelet (in his best tuned room?) look quite similar to the total tendency of my system (in my somewhat tuned room; ref. here) shown below.

Best tuned (including 0.1 msec precision time alignment) latest total Fq response as of August 3 2023 (ref. here);

and REW-Wavelet of my system in my room (rather old data in April 2020 though; ref. here);