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Dirac Live, FIR-filter - Yes, No?

amirm

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#21
@amirm , you're an engineer, I know you are aware that if Dirac Live correction cannot be verified by REW measurement it simpy isn't good.
I have not tried to replicate multiple point measurements of Dirac. And regardless, in acoustics, the ear is king. Measurements can be tricky and highly misleading depending on what is measured and is interpreted. To that point, Dirac sounds good to me.
 

Krunok

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#22
I have not tried to replicate multiple point measurements of Dirac. And regardless, in acoustics, the ear is king. Measurements can be tricky and highly misleading depending on what is measured and is interpreted. To that point, Dirac sounds good to me.
Sure, let the ear be the king, but that is quite a subjective statement coming from an expert in measurement. In order for you to be consistent with that statement I suggest you don't fire up your measuring equipment when evaluating next DAC or amp and let your ear be the king instead of posting measurement figures. For the same reason I also suggest you rename the website to "www.audioearreview.com". ;)
 

amirm

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#23
Sure, let the ear be the king, but that is quite a subjective statement coming from an expert in measurement. In order for you to be consistent with that statement I suggest you don't fire up your measuring equipment when evaluating next DAC or amp and let your ear be the king instead of posting measurement figures. For the same reason I also suggest you rename the website to "www.audioearreview.com". ;)
That is how the science works. Great quote from Dr. Toole's book:

1546727349328.png


May also want to read my article on the same topic: https://www.audiosciencereview.com/...ds/perceptual-effects-of-room-reflections.13/

There is a big difference between sound reproduction in rooms and electronic devices. You will see that reflected in my views.
 

Kal Rubinson

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#24
It can't because it has you measure multiple spots so naturally you can't repeat the same measurements afterward. ...................................................................The only multi-measurement system I know that tells the truth here is Harman ARCOS. It uses multiple microphones in a fixed configuration so it can remeasure with consistency.
This is soluble. All you need to do is to construct a 3D grid-frame with microphone mounts at fixed positions. Then, you can use multiple mics with a switch (greater convenience) or a single mic (lower cost). I've seen John Atkinson use a variant of this when he makes measurements at my house.
 

Krunok

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#25
That is how the science works.
May also want to read my article on the same topic: https://www.audiosciencereview.com/...ds/perceptual-effects-of-room-reflections.13/

There is a big difference between sound reproduction in rooms and electronic devices. You will see that reflected in my views.
Sure, that is how science works according to you - trust your ears when it comes to judging speakers response and promoting Dirac Live, but when it comes to DACs every fraction of 0.000X% of THD counts. I can only congratulate you on your consistency. ;)
 

amirm

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#26
Sure, that is how science works according to you - trust your ears when it comes to judging speakers response and promoting Dirac Live, but when it comes to DACs every fraction of 0.000X% of THD counts. I can only congratulate you on your consistency. ;)
My consistency is to audio science. In acoustics, the science says two ears and a brain work very differently than a single microphone. That how your brain interprets two constantly differing signals from each ear is complex and way beyond what a single measurement can show you. If you want to make up your own version of this science you are welcome but don't ask me to follow. I am standing on shoulders of many giants when I state this. The Internet is full of misconceptions and misuse of measurements for acoustics.

Just recall how the sound of your loved ones don't change when you hear them in different rooms in your house even though acoustics change dramatically.

As to Dirac, I have no motivation to promote it one bit. My company and my own preference is for JBL Synthesis ARCOS system. Dirac is a competitor to that. It is just that the Dirac software works for me and I reported the same. There are other systems which have not and you don't see me recommending them.
 

DonH56

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#27
This is soluble. All you need to do is to construct a 3D grid-frame with microphone mounts at fixed positions. Then, you can use multiple mics with a switch (greater convenience) or a single mic (lower cost). I've seen John Atkinson use a variant of this when he makes measurements at my house.
@Kal Rubinson -- Is that in the Stereophile archives, Kal? I'd like to see what he did and how it worked out.

I have tried it and decided, except when I want to be anal about trying to match measurements, it doesn't really matter for room correction. The final result is an amalgamation of the different measurements so the final curve may (and in general does) not match any one of the previous measurement positions. While I have a handful of boom mics, the most I ever tried was three fixed positions, and I moved the mic from stand to stand (boom mic stands). The measurements matched the measurements shown by Dirac Live pretty closely, but the end result was not terribly close. If I only do one spot, and measure at the same spot, then the results (measured after correction) generally matches the projected (simulated) response but the real measurement has a lot more wiggles in it...

I have tried it for others and when making changes to my room and found the match is pretty variable... My room is pretty dead and the match was pretty good; generally less so on a live(lier) room.

Like @amirm, I tend to agree with Dr. Toole that it is too easy to get wrapped up in acoustical measurements and such without knowing what really matters. It is fairly straightforward to plumb a DAC to an AP analyzer and get accurate, repeatable results. Much harder in a room, and with so many variables also harder to interpret the results. The brain is one heck of a processor...

Sure, that is how science works according to you - trust your ears when it comes to judging speakers response and promoting Dirac Live, but when it comes to DACs every fraction of 0.000X% of THD counts. I can only congratulate you on your consistency. ;)
I suggest you read again what Amir wrote and what he quoted from Dr. Toole. Almost everything you stated is misleading and/or out of context.
 
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Kal Rubinson

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#28
@Kal Rubinson -- Is that in the Stereophile archives, Kal? I'd like to see what he did and how it worked out.
Nope. OTOH, I do agree with your conclusions about the value of re-assessing the results by attempting to recreate the same paradigm.
 

Krunok

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#29
My consistency is to audio science. In acoustics, the science says two ears and a brain work very differently than a single microphone. That how your brain interprets two constantly differing signals from each ear is complex and way beyond what a single measurement can show you. If you want to make up your own version of this science you are welcome but don't ask me to follow. I am standing on shoulders of many giants when I state this. The Internet is full of misconceptions and misuse of measurements for acoustics.

Just recall how the sound of your loved ones don't change when you hear them in different rooms in your house even though acoustics change dramatically.

As to Dirac, I have no motivation to promote it one bit. My company and my own preference is for JBL Synthesis ARCOS system. Dirac is a competitor to that. It is just that the Dirac software works for me and I reported the same. There are other systems which have not and you don't see me recommending them.
Are you saying science doesn't work with speakers? Logic thinking also doesn't work?

How about this? Dirac Live requires you to take 9 measurements over the listening window. It than averages them in order to make a correction filter.
There is a simple way to verify how good job it has done: take the same 9 measurements with REW with Dirac Live correction active, average them and check how close they are to the predicted response. What I find unusual is that you said you did that and the results you got were not close to Dirac Live predisction, yet you're still claiming it sounds good to your ear. Well of course it does, it probably didn't make thing worse, but neither it got them right, otherwise your REW measurement would confirm it.

I did the same procedure with my manual correction method in rePhase and it took me 4 iterations to get things right. 1st of them also sounded better than without the correction but control measurement revealed it is far from perfect, so I made some adjustments. And some more after that. After 4 iterations I got the result I posted here and that is exactly the reason why I think those automated room EQ software solutions are failing - they make only 1 attempt and stop there. They don't even allow you to check what have they done and they don't allow you to adjust further until the job is done as it should be. I'm not saying you have any kind of commercial reason to praise Dirac Live (or any other solution), I simply don't understand how can you promote it as it doesn't make a very good job correcting room response. As you have cheked yourself with REW you are aware of it, yet you are still claiming it did a good job as it sounds good to your ear. Sure it does - but not as good as it should be. And this truth should be told loud and clearly on a scientific forum like this.
 

RayDunzl

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#31
"So, controlling how well Dirac Live made corrections by repaeting the measurement at the same 9 points used initially by Dirac Live is misleading and/or out of context? Oh boy.. :facepalm: :facepalm: "

Taking 9 measurements and applying a simple average may not yield the same result as taking 9 measurements and applying a proprietary algorithm to determine a corrective amplitude/phase filter.

Maybe I haven't stated that succinctly, but you can probably acquire my drift.

*disclaimer - I use single point measure and call it a day
 

DonH56

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#32
^^^ Correct.

And what I felt was out of context were the statements I quoted wherein @Krunok was attacking Amir and nothing else, nothing really to do with the Dirac Live measurements. Specifically and only the lines in this quote:

Sure, that is how science works according to you - trust your ears when it comes to judging speakers response and promoting Dirac Live, but when it comes to DACs every fraction of 0.000X% of THD counts. I can only congratulate you on your consistency. ;)
As I felt in our last interaction, it is better if I stay out of the way, and not interfere nor take sides when our experience differs.
 
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amirm

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#33
How about this? Dirac Live requires you to take 9 measurements over the listening window. It than averages them in order to make a correction filter.
There is a simple way to verify how good job it has done: take the same 9 measurements with REW with Dirac Live correction active, average them and check how close they are to the predicted response. What I find unusual is that you said you did that and the results you got were not close to Dirac Live predisction, yet you're still claiming it sounds good to your ear. Well of course it does, it probably didn't make thing worse, but neither it got them right, otherwise your REW measurement would confirm it.
My REW measurement was from a single spot, not multiple (ala Dirac). As I explained I can't repeat a multi-point measurement scheme (without a fixture as Kal explained).
 

amirm

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#34
I did the same procedure with my manual correction method in rePhase and it took me 4 iterations to get things right. 1st of them also sounded better than without the correction but control measurement revealed it is far from perfect, so I made some adjustments. And some more after that. After 4 iterations I got the result I posted here and that is exactly the reason why I think those automated room EQ software solutions are failing - they make only 1 attempt and stop there. They don't even allow you to check what have they done and they don't allow you to adjust further until the job is done as it should be. I'm not saying you have any kind of commercial reason to praise Dirac Live (or any other solution), I simply don't understand how can you promote it as it doesn't make a very good job correcting room response. As you have cheked yourself with REW you are aware of it, yet you are still claiming it did a good job as it sounds good to your ear. Sure it does - but not as good as it should be. And this truth should be told loud and clearly on a scientific forum like this.
I didn't promote anything. I explained my experience with Dirac. I actually plan to write a tutorial for how to use REW for manual tuning.

As to your solution, I don't know if you got the best sound or most pretty graph. Or what graph and method you used to evaluate what you were doing. It may all be right, or not. You haven't explained objectively in detail what you are doing.

And no, automatic solutions are not failing. Did you not read the article I wrote on automatic correction of multiple subs and multiple mains? https://www.audiosciencereview.com/...s/computer-optimization-of-room-acoustics.12/

1546841987582.png


Your experience seems to only be with low-end systems....
 

Blumlein 88

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#37
Wondering about the single point vs multi-point room correction measurement situation. Are you giving up a lot by measuring only at the listening position? As usual it depends.

I used REW to measure in six positions. The center LP, one foot right of the LP, and one foot left of the LP. Then moved back one foot and repeated. So 6 measurements on a 3 x 2 foot grid. 12 feet from the speaker is the LP.

First all 6 measures with no smoothing. Which looks rather poor. Even for a given measurement.
unsmoothed 6 points.png

But our ears don't really hear that. They have some smoothing capability. So I applied 1/6th octave smoothing. It looks better. This is about the kind of smoothing in the mids and above for our ears.
one sixth smoothing6 points.png


Then I used an ERB smoothing filter. It looks not terrible now.
ERB smoothed 6 pts.png


That looks better still. Our ears will hear first arrival sound mostly plus do some smoothing themselves. So the last one may be close to our perception. Above 1 khz the ERB smoothed responses fit into a 2 db wide window. Below 500 hz the room modes will have an effect of course. And something of a transition in between.

I don't know what Dirac and other softwares do, but they probably do some sort of averaging or smoothing among other things. It strikes me that any of the ERB smoothed response measurements used to EQ the result isn't going to sound radically different (maybe barely noticeable) to any of the others or even an average of them all. So single point measurements probably work okay for this.
 

Sal1950

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#38
I don't know what Dirac and other softwares do, but they probably do some sort of averaging or smoothing among other things. It strikes me that any of the ERB smoothed response measurements used to EQ the result isn't going to sound radically different (maybe barely noticeable) to any of the others or even an average of them all. So single point measurements probably work okay for this.
Nice bit of work D! Really visualizes what the software sees of 6 different measurements. I guess we can all take away something different but I can see where doing and calculating some type of averaging, maybe giving some extra power to the MLP, could be of some advantage below 1k.
YMMV
 

RayDunzl

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#39

RayDunzl

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#40
Here are my 7 "across the top of the sofa" measures from two years ago, with "flat" DSP.

Traces 1 through 7 are left to right, with trace 4 (orange) the center.

1547285110154.png


Impulse Response, far left, as an example:

1547285228155.png


Center, Vector Average, and Simple Average: (never looked at vector average before)

1547285719923.png
 
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