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Post by vmbray on Mar 1, 2021 15:30:10 GMT -5
I think most here are trying to be consistent. I have a railing that needs replacing anyway behind the seats so I just stuck blue tape on top with marks at the center line, and then spaced across at 20” spacing per Dirac 40-60cm between measurement points. I use a tape measure to position the mic forward from the railing, at about the same distances give of take an inch. I make sure the bass eq/boost is off in minidsp and I disable the near field subs. I’ve done the subs both ways, last time I curtained it off so it wouldn’t touch the subs but this time I let it do the main subs but not the near field. I didn’t measure the two back bottom spots because my seat headrest blocks line of sight from the surround on the opposite side. I added the umik2 to have more headroom and for general rew use, and it does allow measurements at a little higher level.
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Post by leonski on Mar 1, 2021 18:52:52 GMT -5
I think most here are trying to be consistent. I have a railing that needs replacing anyway behind the seats so I just stuck blue tape on top with marks at the center line, and then spaced across at 20” spacing per Dirac 40-60cm between measurement points. I use a tape measure to position the mic forward from the railing, at about the same distances give of take an inch. I make sure the bass eq/boost is off in minidsp and I disable the near field subs. I’ve done the subs both ways, last time I curtained it off so it wouldn’t touch the subs but this time I let it do the main subs but not the near field. I didn’t measure the two back bottom spots because my seat headrest blocks line of sight from the surround on the opposite side. I added the umik2 to have more headroom and for general rew use, and it does allow measurements at a little higher level. I would be curious as to what you'd get with 3x or 4x repeats as identical as you could make them. You have the error built into the system and mic along with YOUR inherent inability ot put the mic EXACTLY where it was and pointing EXACTLY the same. |
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Post by vmbray on Mar 1, 2021 19:31:25 GMT -5
I can envision doing what Ethan describes and hanging a plumb bob in one spot to align the mic accurately and doing a one point cal and repeat but not multiple points multiple times.
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Post by leonski on Mar 1, 2021 19:56:46 GMT -5
I can envision doing what Ethan describes and hanging a plumb bob in one spot to align the mic accurately and doing a one point cal and repeat but not multiple points multiple times. Sure. ONE point with the mic unmoved between efforts would help decide how REPEATABLE your (measurement) system is. Better still would be AFTER that try to removed and resetup the microphone for each measurment. Each of those trials tells you something different. Than it gets much more complicated. Ultimately, you need to use 3 different operators doing the same operation to complete the process.... |
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Post by markc on Mar 2, 2021 2:52:32 GMT -5
I can envision doing what Ethan describes and hanging a plumb bob in one spot to align the mic accurately and doing a one point cal and repeat but not multiple points multiple times. If you leave the plumb bob in place and at the correct height after generating Dirac filters, you can then align your head so that the plumb bob touches the same spot on top of your head, and ensure repeatability anytime you need to do critical listening. If it is just casual listening then feel free to allow the plumb bob to be up to 5mm displaced. Top tip: Get a small India ink dot tattooed at the correct place on your scalp so that someone else can easily verify that you are sat where you need to be sat. |
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Post by KeithL on Mar 2, 2021 10:09:37 GMT -5
Really...... just pick yourself up one of those dentist chairs with the head rest...... (but make sure you pick one that locks into position)
And, for the DIYers, you can mount a LASER pointer on the front wall, up and to the front center at about a 45 degree angle... Then you can use a mirror to verify where the spot hits your forehead.
Or you could use a variation of the old garage parking trick...
Hang a tennis ball on a string directly over your listening position - and sit so that it just touches the top of your head...
I can envision doing what Ethan describes and hanging a plumb bob in one spot to align the mic accurately and doing a one point cal and repeat but not multiple points multiple times. If you leave the plumb bob in place and at the correct height after generating Dirac filters, you can then align your head so that the plumb bob touches the same spot on top of your head, and ensure repeatability anytime you need to do critical listening. If it is just casual listening then feel free to allow the plumb bob to be up to 5mm displaced. Top tip: Get a small India ink dot tattooed at the correct place on your scalp so that someone else can easily verify that you are sat where you need to be sat. |
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Post by vmbray on Mar 2, 2021 10:14:40 GMT -5
I have a bright harsh effect after running Dirac and am trying to decide if it’s a total waste of time or not. I’ve read enough comments where smart people concluded it sounds worse and forget it. I’m trying to make up my own mind and I’m not talking about a subtle effect you can argue about. My kid was watching with me and he was like man that’s harsh at -18 so I turned to the other preset and we instantly turned up the volume, it was overall louder and more impact, house is shaking, not harsh. So yeah I’m interested in the scientific aspect but I haven’t said anything that should lead anyone to conclude I’ve got my head strapped in to avoid some null or something so let’s just be cool in here.
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ttocs
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Post by ttocs on Mar 2, 2021 10:21:56 GMT -5
I have a bright harsh effect after running Dirac and am trying to decide if it’s a total waste of time or not. I’ve read enough comments where smart people concluded it sounds worse and forget it. I’m trying to make up my own mind and I’m not talking about a subtle effect you can argue about. My kid was watching with me and he was like man that’s harsh at -18 so I turned to the other preset and we instantly turned up the volume, it was overall louder and more impact, house is shaking, not harsh. So yeah I’m interested in the scientific aspect but I haven’t said anything that should lead anyone to conclude I’ve got my head strapped in to avoid some null or something so let’s just be cool in here. I use a laser measurer and the same 3 points to get the mic in the same place every time, within a few millimeters. When I'm testing stuff I just use a single mic position and force Dirac to proceed, it has a nag popup asking am I sure? |
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Post by vmbray on Mar 2, 2021 11:35:29 GMT -5
I use a laser measurer and the same 3 points to get the mic in the same place every time, within a few millimeters. When I'm testing stuff I just use a single mic position and force Dirac to proceed, it has a nag popup asking am I sure? Makes sense for repeatability of measurements and comparison purpose, and to be scientific about it which is how you learn. For doing a calibration with multiple points I’m sure it doesn’t make a huge difference and also when I look at the rew measurements of what Dirac does I wonder why I bother putting a target curve because it’s got a mind of it’s own. Now that is probably due to doing a 17 point cal instead of the lesser number of points now that I think about it, with my room and the sloped ceilings maybe too many points is causing Dirac to try to be everything to everyone and short circuiting internally. Hoping to get some time to play with it with fewer points soon. |
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Post by marcl on Mar 2, 2021 12:53:02 GMT -5
Really...... just pick yourself up one of those dentist chairs with the head rest...... (but make sure you pick one that locks into position)
And, for the DIYers, you can mount a LASER pointer on the front wall, up and to the front center at about a 45 degree angle... Then you can use a mirror to verify where the spot hits your forehead.
Or you could use a variation of the old garage parking trick...
Hang a tennis ball on a string directly over your listening position - and sit so that it just touches the top of your head...
If you leave the plumb bob in place and at the correct height after generating Dirac filters, you can then align your head so that the plumb bob touches the same spot on top of your head, and ensure repeatability anytime you need to do critical listening. If it is just casual listening then feel free to allow the plumb bob to be up to 5mm displaced. Top tip: Get a small India ink dot tattooed at the correct place on your scalp so that someone else can easily verify that you are sat where you need to be sat. Attachments:
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ttocs
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Post by ttocs on Mar 2, 2021 22:39:15 GMT -5
Since FW-2.2 I've done three quick Dirac runs to check some things. The first one crashed during the filter loading into the processor and the app completely shutdown. The second and third times had unusual behavior during and after filter loading, but didn't shutdown spontaneously, but instead the app displayed a message saying that a problem had occurred and the program would shut down. All three times the filters that were loaded were perfectly useable without incident.
Other than the firmware update, the only other change in the chain is updating my MacBook Pro to Big Sur from Mojave. After doing so I uninstalled Dirac 3.0.11 using the Dirac uninstall tool, rebooted the computer, then installed 3.0.13.
I'm not saying this version is running properly, but things seem better. Whether it's the firmware, not likely IMO, or the updated OS, more likely, Dirac 3.0.13 is more useable.
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Post by vmbray on Mar 2, 2021 23:30:55 GMT -5
I’m on windows and Dirac app crashed after filter had transferred. I got the green banner that it succeeded and then Dirac checked out. Filter had transferred and worked.
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Post by JKCashin on Mar 3, 2021 0:44:41 GMT -5
Since FW-2.2 I've done three quick Dirac runs to check some things. The first one crashed during the filter loading into the processor and the app completely shutdown. The second and third times had unusual behavior during and after filter loading, but didn't shutdown spontaneously, but instead the app displayed a message saying that a problem had occurred and the program would shut down. All three times the filters that were loaded were perfectly useable without incident. Other than the firmware update, the only other change in the chain is updating my MacBook Pro to Big Sur from Mojave. After doing so I uninstalled Dirac 3.0.11 using the Dirac uninstall tool, rebooted the computer, then installed 3.0.13. I'm not saying this version is running properly, but things seem better. Whether it's the firmware, not likely IMO, or the updated OS, more likely, Dirac 3.0.13 is more useable. Most people are recommending 3.0.11, saying that 3.0.13 crashes quite a bit (like 50% of the time or maybe even more?) |
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ttocs
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Post by ttocs on Mar 3, 2021 1:12:15 GMT -5
Since FW-2.2 I've done three quick Dirac runs to check some things. The first one crashed during the filter loading into the processor and the app completely shutdown. The second and third times had unusual behavior during and after filter loading, but didn't shutdown spontaneously, but instead the app displayed a message saying that a problem had occurred and the program would shut down. All three times the filters that were loaded were perfectly useable without incident. Other than the firmware update, the only other change in the chain is updating my MacBook Pro to Big Sur from Mojave. After doing so I uninstalled Dirac 3.0.11 using the Dirac uninstall tool, rebooted the computer, then installed 3.0.13. I'm not saying this version is running properly, but things seem better. Whether it's the firmware, not likely IMO, or the updated OS, more likely, Dirac 3.0.13 is more useable. Most people are recommending 3.0.11, saying that 3.0.13 crashes quite a bit (like 50% of the time or maybe even more?) Yes, I'm one who recommends 3.0.11 also. Just pointing out that since updating the OS and firmware the virtually 100% crash rate I experienced is suddenly 33%, albeit with only sample pool of 3 uses, but just the fact that it only crashed the one time out of three is unique in my experience. I've installed that version several times thinking it might have been a less than optimal installation, and on two of the installs it crashed badly every time. |
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Post by tngiloy on Mar 3, 2021 18:26:34 GMT -5
I am planning to re-run Dirac soon.
Is it still advisable to set speaker levels to 0 before running Dirac ? Or doesn't it matter?
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Post by geebo on Mar 3, 2021 18:38:18 GMT -5
I am planning to re-run Dirac soon. Is it still advisable to set speaker levels to 0 before running Dirac ? Or doesn't it matter? As far as running Dirac it won't matter. But when your done the values you have in Levels will add to Dirac's final result. So in the end it does matter. Set them to zero before or after running Dirac but do set them to zero. You can then fine tune the levels with an SPL if desired. |
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Post by marcl on Mar 5, 2021 10:00:10 GMT -5
I first heard of Dirac Live watching this Home Theater Geeks episode in 2015. It was worth a look again after all these years and hundreds of Dirac Live calibrations and a couple thousand hours of listening. Mathias Johansson is one of the founders of Dirac Research and he goes through the theory behind Dirac's unique approach to room correction, particularly for Impulse Response. youtu.be/2zEKoJAKFbM |
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Post by klinemj on Mar 5, 2021 10:11:33 GMT -5
I first heard of Dirac Live watching this Home Theater Geeks episode in 2015. It was worth a look again after all these years and hundreds of Dirac Live calibrations and a couple thousand hours of listening. Mathias Johansson is one of the founders of Dirac Research and he goes through the theory behind Dirac's unique approach to room correction, particularly for Impulse Response. youtu.be/2zEKoJAKFbMI first actually heard of it via Emotiva prior to the XMC-1 launch. I can't recall who it was from Dirac who came, but they gave a demo and a talk about how it worked. I was sold right away based on what I heard. And, as a Chemical Engineer, I loved the math/tech behind it. Mark |
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ttocs
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Post by ttocs on Mar 5, 2021 10:44:42 GMT -5
I first heard of Dirac Live watching this Home Theater Geeks episode in 2015. It was worth a look again after all these years and hundreds of Dirac Live calibrations and a couple thousand hours of listening. Mathias Johansson is one of the founders of Dirac Research and he goes through the theory behind Dirac's unique approach to room correction, particularly for Impulse Response. youtu.be/2zEKoJAKFbMThis was good to review, thanks for the reminder! Saw this a few years ago, but now am able to better understand the discussion. |
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Post by marcl on Mar 5, 2021 11:06:54 GMT -5
I first heard of Dirac Live watching this Home Theater Geeks episode in 2015. It was worth a look again after all these years and hundreds of Dirac Live calibrations and a couple thousand hours of listening. Mathias Johansson is one of the founders of Dirac Research and he goes through the theory behind Dirac's unique approach to room correction, particularly for Impulse Response. youtu.be/2zEKoJAKFbMThis was good to review, thanks for the reminder! Saw this a few years ago, but now am able to better understand the discussion. Same here. I understand now how the short time frame impulse is nearly identical for all positions and can be corrected. Same for the frequency response below the transition frequency. Longer time frame impulse and higher frequency amplitude, they look for similarities between positions to correct and ignore the rest, especially very narrow differences. They show the average as a reference, but it's not the average that they are literally correcting in either amplitude or time domain. This is why it's so important to take more measurements ... too few measurements will likely result in overcorrection which will cause problems a short distance from the MLP. Discussions of Toole's research and recommendations on room correction don't address impulse response correction at all as far as I can recall ... I may be wrong, but I think he has always focused on the limitations of room correction in the frequency/amplitude domain and not the time domain. |
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