Share your in-room measurements?

[Deleted member 48726]

I'm not reading that 27 MB file. Especially not served like that. Explain to me why there is something hidden in the frequency response that we can hear but doesn't show up with a mic at listening position.

Explain to me why each individual speakers anechoic, corrected by Dirac, response is relevant when we are positioned at the listening position and hear the sum of to taste corrections done to the signal.

 

[Keith_W]

I'm not reading that 27 MB file. Especially not served like that. Explain to me why there is something hidden in the frequency response that we can hear but doesn't show up with a mic at listening position.

You totally should. I paid $90 for my copy and he's giving it to you for free. It was the best $90 I ever spent on audio.

 

[YSC]

Measuring roughly 10' square with an 8' ceiling, they say I have bad dimensions for getting good room response. Initially, that was definitely the case. It took some perseverance (and lots of room treatment), but I'm incredibly happy with the end result. My system's in room response now matches my target curve incredibly well in both channels from 20Hz-20kHz, and I've done sweeps up to 105 dB with no compression.

The setup is a nearfield desktop system using Revel M105s and four sealed 8" subwoofers that I made using Dayton Ulitmax drivers. Dual Crown amps provide 525w to each Ulitmax, which are running as stereo pairs, making each L/R channel individually full range. The processor is a miniDSP Flex running Dirac Live, with 2 channels going to a Topping PA5 for the Revels, and 2 channels going to a miniDSP 2x4HD to feed the Crowns/subs.

I'm using a 24dB/oct crossover at 80Hz, and then setting delays on each channel according to the measured distances to my ears. I use Tightly Focused Imaging in Dirac Live since the system is used at a desk, and I have my own target I use that I've added to the graphs.

I have to say, I am very impressed at just how tight Dirac was able to correct each channel!

Before Calibration:

View attachment 282168
Dirac Live Calibrated:

View attachment 282169
After how simple the final calibration process ended up being, I feel a bit foolish for how much I was overthinking things. I knew I had to set the XO and delays before running Dirac, and that I should put care into getting them right first. I measured the distances from the drivers to my ears, and set the delays all based on that. I took some initial REW sweeps before calibration, and I didn't like what I saw. Before even trying an initial calibration, I started fine tuning delays until each native response channel looked best to my eyes. Then I ran Dirac and did not get the results I was hoping for. I kept fine tuning and tweaking, moving onto the crossovers, but I was getting disappointing results in Dirac every time. I tried to use MSO to sort it out, and that also went poorly.

I was getting frustrated. By this time, I'd spent days monkeying around. I finally considered that I had never actually attempted to run Dirac with the initial delays that I had calculated based on distance, so why not at least see what Dirac can do with it. Well it turns out that the delays based on actual measurements nailed the best result. Go figure! I could have saved days of monkeying around!

Live and learn! At least I won in the end. It really does sound fantastic, and it's a joy to listen to this rig all day while I work from home.

System diagram is attached.

I think that's also partly because DIRAC is kind of a all in one solution that it was designed to do all corrections for you so if you've applied some of the tweaks prior it can make things worse.. did you try also limiting the correction to below schroeder frequency to see if that sounded even better?

 

[IamJF]

That's excellent. I wonder what dimensions your room has and which acoustic treatment was need to get these results. Most likely I've never been in a room with such a low reverb. Must be an overwhelming experience.

The room is about 3x4m - so pretty small. Helps with bass arrays ;-) The concept behind is a non environment room - all surfaces but the floor and front are absorbing. So it isn't an anechoic chamber but you get very little influences from the room.
I used BCA (broadband compact absorbers) in walls an ceilings to get absorption at low frequencies. And additional absorption where it was neccesary.

Some people really dislike the dead feeling when you enter the room. But most get used to it quickly. Mixes and masterings translate very well cause you simply hear what your source material is doing - even lowest frequencies.
But listening is a little different as in a big room - HiFi people are often used to these reflections and like the widening effect, which is totally missing in this room.

 

[thewas]

It would show up in an anechoic measurement.

Repeating this doesn't make it true.

Correct, but please remove above illegal link to the book of Toole.

Let me add few more quotes from him:

"The next step is to find prominent spectral peaks below about 500 Hz and attenuate them using a parametric equalizer, another relatively simple task if one has access to DSP in the signal path. Avoid filling narrow dips. They are not as audible as they are visible - humans respond readily to excessive sound at specific frequencies (resonances) but largely ignore narrow dips; an absence or deficiency in sound. The major commercial algorithms differ mainly in how they decide which peaks to attenuate and which dips to fill."
Source: https://www.audiosciencereview.com/...y-without-measurement.7127/page-3#post-162798

"The dip will be most pronounced when listeners are in a dominant direct sound field, as in near-field listening. Reflected sounds help fill in the hole, as Shirley et al. found. It is a non-minimum-phase phenomenon and therefore cannot be "corrected" by normal minimum-phase EQ. Since the dip exists only for the listener in the sweet spot correcting the dip with an EQ bump means that everybody else in the room hears an annoying bump. Probably not a good idea."
Source: https://www.audiosciencereview.com/...t-design-available.19024/page-29#post-1419704

Personally I am experimenting with DRC (Sbragion's DRC, Acourate, Dirac, REW and more) since almost 20 years now and have learned the hard way that corrections of the frequency responses at the listening position that look perfectly smooth/flat usually sound poorly, I was wondering why Genelecs GLM corrections are so minimal and by now I know the answer.

Also this thread can be quite an eye opener, the tester also tested several DRC products and like myself ende in just doing corrections manually in REW:

Comparison of DRCs: Dirac Live for Studio, IK Multimedia ARC System 3 and Sonarworks Reference 4 Studio edition

[MOD EDIT: This is a member contribution] Hi all, Lately I was playing a bit with digital room correction (DRC) SW to see if I can tame the bass in our living room with a pair of Revel M16 (no subs) so I thought it could be useful to share my findings. Some of my in-room measurements are...

www.audiosciencereview.com

 

[BrokenEnglishGuy]

Hi
I didnt notice this thread
This is the measurements from my R7s in a small room 3 x 3 meters.. yes its small
This was using APO EQ + REW

Tons of EQ, different for Left and Right.. after this is the measuements~

Sometimes when i measured the speaker the HF slope change, this is the graph after a bit of listening.. i ended EQ the 120hz~ dip to me sounds better with a ridiculous +9dB xD like the red graph above

I ended with a mix of these measurements, i don't have the final measurements because i had the UMIK-1 only 2 days

And this disaster its the original R7 without EQ

 

[Deleted member 48726]

Look at Dirac before and after. It does what it says it does. That is correct the sound to whatever likings at you listening position. I then should not care one bit of how my corrected left speaker might sound in an anechoic chamber with that correction. That's just plain nonsense.
Then that speaker has been taken out of the symbiose it was in, in room with the other speaker, being listened to at 3 m. distance, corrected.

Dirac Live is the single most valuable investment I've ever made in HiFi. The ability to tailor the sound in combination with whatever phase corrections it does is invaluable to me.
Maybe Toole and others disagree and there are things beyond my hearing that are "wrong".
Oh well..

 

[PowerSerge]

Hi
I didnt notice this thread
This is the measurements from my R7s in a small room 3 x 3 meters.. yes its small
This was using APO EQ + REW

Tons of EQ, different for Left and Right.. after this is the measuements~

Hi
I didnt notice this thread
This is the measurements from my R7s in a small room 3 x 3 meters.. yes its small
This was using APO EQ + REW

Tons of EQ, different for Left and Right.. after this is the measuements~

Sometimes when i measured the speaker the HF slope change, this is the graph after a bit of listening.. i ended EQ the 120hz~ dip to me sounds better with a ridiculous +9dB xD like the red graph above

I ended with a mix of these measurements, i don't have the final measurements because i had the UMIK-1 only 2 days

And this disaster its the original R7 without EQ

Youre using 130db scale for your corrected measurements and 65 db scale for your uncorrected measurement. On top of that your using smoothing on the corrected measurements and no smoothing for the uncorrected measurement so of course it looks far worse before eq.

 

[YSC]

Correct, but please remove above illegal link to the book of Toole.

Let me add few more quotes from him:

"The next step is to find prominent spectral peaks below about 500 Hz and attenuate them using a parametric equalizer, another relatively simple task if one has access to DSP in the signal path. Avoid filling narrow dips. They are not as audible as they are visible - humans respond readily to excessive sound at specific frequencies (resonances) but largely ignore narrow dips; an absence or deficiency in sound. The major commercial algorithms differ mainly in how they decide which peaks to attenuate and which dips to fill."
Source: https://www.audiosciencereview.com/...y-without-measurement.7127/page-3#post-162798

"The dip will be most pronounced when listeners are in a dominant direct sound field, as in near-field listening. Reflected sounds help fill in the hole, as Shirley et al. found. It is a non-minimum-phase phenomenon and therefore cannot be "corrected" by normal minimum-phase EQ. Since the dip exists only for the listener in the sweet spot correcting the dip with an EQ bump means that everybody else in the room hears an annoying bump. Probably not a good idea."
Source: https://www.audiosciencereview.com/...t-design-available.19024/page-29#post-1419704

Personally I am experimenting with DRC (Sbragion's DRC, Acourate, Dirac, REW and more) since almost 20 years now and have learned the hard way that corrections of the frequency responses at the listening position that look perfectly smooth/flat usually sound poorly, I was wondering why Genelecs GLM corrections are so minimal and by now I know the answer.

Also this thread can be quite an eye opener, the tester also tested several DRC products and like myself ende in just doing corrections manually in REW:

Comparison of DRCs: Dirac Live for Studio, IK Multimedia ARC System 3 and Sonarworks Reference 4 Studio edition

[MOD EDIT: This is a member contribution] Hi all, Lately I was playing a bit with digital room correction (DRC) SW to see if I can tame the bass in our living room with a pair of Revel M16 (no subs) so I thought it could be useful to share my findings. Some of my in-room measurements are...

www.audiosciencereview.com

actually I think also boosting the peaks could sometimes create artificial clipping out of tones, on the dac side, so it will sound distorted.

 

[napfkuchen]

The room is about 3x4m - so pretty small. Helps with bass arrays ;-) The concept behind is a non environment room - all surfaces but the floor and front are absorbing. ...
I used BCA (broadband compact absorbers) in walls an ceilings to get absorption at low frequencies. And additional absorption where it was neccesary.

My room is 4 x 3,5m, but the speakers had to be placed at the longer wall. With some standard absorbers (5-10 cm deep at first reflection points and rear wall, deeper absorbers in front corners) the RT60 now has a slope from 0,4s at 60 Hz to 0,25s at 10 kHz. But especially below 200 Hz there is still "room" for improvement.

 

[Zensō]

I’ve been using Sonarworks for years with pretty good results, but until today I never checked the pre-EQ output against the post-EQ output using REW. Here’s the before and after. This is in my small, non-treated home office. Genelec 8030C with the listening position at 90cm, psychoacoustic smoothing, flat target.

 

[Deleted member 48726]

You totally should. I paid $90 for my copy and he's giving it to you for free. It was the best $90 I ever spent on audio.

I don't care. I have seen the section from Toole where he writes about room corrections. I don't think Toole is absolutely right in everything and there seems to be an almost religious following here where some people just quote Toole as a definitive answer. That's not right. Also the knowledge that's in this book is available other places. Like here on ASR for example where you can actually have a dialogue.

 

[YSC]

I’ve been using Sonarworks for years with pretty good results, but until today I never checked the pre-EQ output against the post-EQ output using REW. Here’s the before and after. This is in my small, non-treated home office. Genelec 8030C with the listening position at 90cm.

View attachment 282470

View attachment 282471

nice one, may I ask what's the smoothing of the graph ?

 

[Deleted member 48726]

nice one, may I ask what's the smoothing of the graph ?

Considerable smoothing.

 

[Zensō]

nice one, may I ask what's the smoothing of the graph ?

Psychoacoustic

 

[YSC]

Psychoacoustic

Is it possible to post the 1/12 or 1/24 results for a view? Wanna see how well they can be standalone

 

[anotherhobby]

That's what I'm convinced has happened.
I'm going to demonstrate the problem by applying the EQ filters to anechoic on-axis response of the M105, which will show how the sound quality is being degraded.

Yes, that is what happened, so I appreciate the call out. Dirac did degrade the sound quality of my M105s. After your comment I pulled the correction back to 550 Hz, mainly choosing that point because there is a smooth transition there where the Dirac measurement intersects the native one. It sounded better to me immediately, but some changes I like to let sit for a while, so I've been listening to it this way since then. Today I finally flipped it back to the full range correction and my opinion hasn't changed, so I'll be leaving Dirac cut back.

I found I also don't like full range Audyssey correction on my Focal Aria 936s. I don't know why I didn't think to try the same thing here, other than just trusting Dirac based on so much seemingly great feedback here and other places.

 

[Deleted member 48726]

Yes, that is what happened, so I appreciate the call out. Dirac did degrade the sound quality of my M105s. After your comment I pulled the correction back to 550 Hz, mainly choosing that point because there is a smooth transition there where the Dirac measurement intersects the native one. It sounded better to me immediately, but some changes I like to let sit for a while, so I've been listening to it this way since then. Today I finally flipped it back to the full range correction and my opinion hasn't changed, so I'll be leaving Dirac cut back.

I found I also don't like full range Audyssey correction on my Focal Aria 936s. I don't know why I didn't think to try the same thing here, other than just trusting Dirac based on so much seemingly great feedback here and other places.

Do you have any data on how Dirac Live "degrades" the sound?

My bet is that you just don't like your speakers corrected but like the colouration they have and the colouration the room adds.

 

[YSC]

Do you have any data on how Dirac Live "degrades" the sound?

My bet is that you just don't like your speakers corrected but like the colouration they have and the colouration the room adds.

somehow I feel that correction below the schoreder frequency is the correct approach, TBH my setup due to partner issue have one speaker having stuffs piled up right next to it creating quite a very close first reflection point, so the location have some more comb filtering in one channel compared to the other, when uncorrected or EQ below schroeder frequency, ignoring the sound is right or not, the stereo image is dead centered, but when I apply full range EQ, though the single LP mic measured result showed good matching for FR, the stereo image shifted by a few feet to one side, it seemed at least in nearfield, our ears can differentiate the direct sound quite well and so it resulted in the image shift if fully corrected, but for the bass frequencies, correction makes perfect result

 

[thewas]

Source of above: https://www.aes.org/e-lib/browse.cfm?elib=17839

It has all been said for several times, above room transition frequency we mainly perceive the direct sound and thus in that region we mainly "correct" the loudspeaker and not the room. For this correction anechoic measurements are better as typical measurements at the LP can have there small peaks and dips due to local reflections which if correcting can deteriorate the linearity of the direct sound. Below is what Toole says about it:

"As I said, because loudspeaker transducers are minimum-phase devices one can use electrical parametric EQ to attenuate the mechanical resonances in transducers - using anechoic data of course. So, if you add a hump to an otherwise neutral/resonance free speaker you have added a resonance. This is why it is crucial to pay attention to what "room equalizers" are doing. If they "see" a ripple in a measured curve caused by acoustical interference of direct and reflected sound, and try to flatten it, they may be adding a resonance and degrading a good loudspeaker."
Source: https://www.audiosciencereview.com/...ut-room-curve-targets-room-eq-and-more.10950/

Above two links give more good insight into the topic.