ZOOMING In REW (and a little Dirac)

[marcl]

Apr 9, 2023 20:45:33 GMT -5 thompson12 said:

I'm just a few miles north of marcl same time zone. I Just have to make time to join in. That was great that you's made it work for Paule. It's nice that you guys record them for the people that can't join in or the people that just prefer to watch and learn.


Mitch

Well then NEXT time come on down!

[msimanyi]

Apr 9, 2023 11:53:34 GMT -5 ttocs said:

I loved how the discussion flowed yesterday!

I like the idea that the discussion might start with a main topic, and then be allowed to flow naturally, as it did yesterday. It's nice to be able to discuss our system setups in our homes including how the home is constructed, which directly relates to how we've managed to use our spaces as we wish.

I totally agree, though now I'm shopping *another* subwoofer* and I have the Magnepan website open to compare the MC1s and MMG Ws for potential use as 6 Atmos speakers.  These discussions aren't kind to my bank account!

* For those who weren't in attendance, it started with the idea of adding a center-channel subwoofer to extend the range of my Martin Logan Illusion center speaker.  I may move my rear subwoofer to that position to test the effect.

[ttocs]

A setting I hadn't noticed till now is that we can set the Smoothing to whatever we like as a default for each new measurement automatically.

[ttocs]

Mar 12, 2023 10:47:57 GMT -5 marcl said:

This is brilliant ... it's what we've always wanted!  Here is how to use REW to measure Atmos channels!

First, here's a video that tells you exactly how to do it.  There's a lot that does not apply to us as we use Emotiva gear and Dirac, but the Atmos part starts at 00:22:46




In order to do the measurements you need the .WAV and .mp4 files located here:

drive.google.com/file/d/1APNO_yTseoPoBoyfwyjGLBTFat8g20_4/view

Watch very carefully.  There are specific steps to disable ASIO and measure From File.  You load the .WAV file after selecting From File in the Measurement screen.  Then you separately play the .mp4 file using Windows Media Player or whatever you have (i.e. you don't play the .mp4 files from within REW).  REW will wait for the chirp and record the sweep.  You get all the usual data.  Brilliant!

Here's the response of my Atmos Tops - Magnepan MMGW Front, Polk OWM5 Rear - with crossovers at 120Hz ... along with all the other channels measured with the usual method.  Psychoacoustic Smoothing.

I was just reviewing this and trying to measure my Tops but the subwoofer is active ALL THE TIME, even with the Tops setup as Large.

I tried crossover settings of 250Hz, 40Hz, setting the Tops as Large, but the frequency response doesn't change. Turning off the subwoofer is not the same as measuring a speaker setup as Large because the XO affects the result.

When I run RTA and use the Spatial Disc I get what I expect to get, crossover settings change the FR, and when setup as Large the FR for the tops is what I was hoping to find which is the response of just each speaker with no subwoofer.

Using the OCA files somehow is using a "preset" BM. I don't know how, but I'm not able to alter how the Height speakers are measured in the low range where BM would be present, or not, if setup as Large.

marcl can you please confirm this?

edit: Thanks Marc for helping me sort this out!

Turns out that, while I was using the Mac mini for this when I first tried these files as an initial test, I was using Windows installed with BootCamp. Today I was just using macOS, duh. So it all works as it should in Windows. USER ERROR.

I can't get the Mac to operate in ATMOS, only with Windows can I get that to work.

[marcl]

I just found that there have been a number of ongoing changes to the REW 5.20.14 Beta. These here are real handy! Can't wait to try them ...

[ttocs]

Using REW Pro with WinOS and trying to get multiple mics to work as an Aggregate Device is proving to be more difficult than with macOS.

marcl, with your Sonicpresence SP15C mics, how do they show up in REW, as a device with L and R channels, or, as two separate microphones and possibly with L&R channels for each?

I am able to get two mics to operate simultaneously using ASIO4All and Enabling both using the ASIO4All Control Panel. But, I'm only able to get both to register recording levels in RTA. In Measurement only one mic or the other will record audio.

I'm still trying to create an Aggregate Device in Windows but haven't found the secret sauce.

[marcl]

May 21, 2023 8:14:22 GMT -5 ttocs said:

Using REW Pro with WinOS and trying to get multiple mics to work as an Aggregate Device is proving to be more difficult than with macOS.

marcl , with your Sonicpresence SP15C mics, how do they show up in REW, as a device with L and R channels, or, as two separate microphones and possibly with L&R channels for each?

I am able to get two mics to operate simultaneously using ASIO4All and Enabling both using the ASIO4All Control Panel. But, I'm only able to get both to register recording levels in RTA. In Measurement only one mic or the other will record audio.

I'm still trying to create an Aggregate Device in Windows but haven't found the secret sauce.

Here's what I see with the SP15C.   I can pick either mic, and if I check Multiple Inputs I can select the two ... one in each drop down.  When I use the SPL meter only the left one responds, but yes in RTA I see both (I had to click the Calibrate button for them to show up).



Edit: If I try to enable both the UMIC and SP15C there are some combinations it won't let me pick.  But with the UMIK as input 1 and SP15C as input 2 ... only the UMIK works in SPL meter.

[ttocs]

May 21, 2023 8:33:05 GMT -5 marcl said:

May 21, 2023 8:14:22 GMT -5 ttocs said:

Using REW Pro with WinOS and trying to get multiple mics to work as an Aggregate Device is proving to be more difficult than with macOS.

marcl , with your Sonicpresence SP15C mics, how do they show up in REW, as a device with L and R channels, or, as two separate microphones and possibly with L&R channels for each?

I am able to get two mics to operate simultaneously using ASIO4All and Enabling both using the ASIO4All Control Panel. But, I'm only able to get both to register recording levels in RTA. In Measurement only one mic or the other will record audio.

I'm still trying to create an Aggregate Device in Windows but haven't found the secret sauce.

Here's what I see with the SP15C.   I can pick either mic, and if I check Multiple Inputs I can select the two ... one in each drop down.  When I use the SPL meter only the left one responds, but yes in RTA I see both (I had to click the Calibrate button for them to show up).

Looks like the SP15C is a single mic with two channels, otherwise, there would be two pairs of entries ending with 1 and 2. In WDM Device List it shows just one entry for the SP15C, and under Inputs it shows both channels of the SP15C.

Each mic notation in applications reads as:
Microphone1 1
Microphone1 2
Mic2 1
Mic2 2

Channel 1 is Left, and Channel 2 is Right.

One important note I came upon last night is that REW will ONLY allow multiple mics with Measure and RTA. The only way around this is to be able to make an Aggregate Device like I've done in macOS. But the aggregate device is just seen as a single mic, so can only produce a single trace.

Multiple mics can each produce individual traces if so desired, so this would be a more powerful implementation than an aggregate device.

[marcl]

May 21, 2023 8:54:06 GMT -5 ttocs said:

May 21, 2023 8:33:05 GMT -5 marcl said:

Here's what I see with the SP15C.   I can pick either mic, and if I check Multiple Inputs I can select the two ... one in each drop down.  When I use the SPL meter only the left one responds, but yes in RTA I see both (I had to click the Calibrate button for them to show up).

Looks like the SP15C is a single mic with two channels, otherwise, there would be two pairs of entries ending with 1 and 2. In WDM Device List it shows just one entry for the SP15C, and under Inputs it shows both channels of the SP15C.

Each mic notation in applications reads as:
Microphone1 1
Microphone1 2
Mic2 1
Mic2 2

Channel 1 is Left, and Channel 2 is Right.

One important note I came upon last night is that REW will ONLY allow multiple mics with Measure and RTA. The only way around this is to be able to make an Aggregate Device like I've done in macOS. But the aggregate device is just seen as a single mic, so can only produce a single trace.

Multiple mics can each produce individual traces if so desired, so this would be a more powerful implementation than an aggregate device.

More quirks ... the Input thing at the bottom right of Measure seems to just open the ASIO4ALL section of Preferences, and it seems to work the same.  I can select channel 1 for the first input and channel 2 for the second input. But if I select channel 2 for the first input, it will only let me have channel 2 for the second input.  But I don't expect the Multiple Inputs measurement to be any different picking from the Measure screen.  I expect it to actually only measure using channel 1.  But I'll verify today.

SP15C is definitely being seen as an unusual device as compared to other multiple input sources that REW might be prepared for.

[marcl]

Repost from the Measuring Thread for anyone seeing this first here .....


Regarding setting levels of all speakers in a 7.1.4 system .... an Hypothesis:

1. The levels of all the speakers on the left side of the room should be the same at the left ear, and the levels of all the speakers on the right side of the room should be the same at the right ear.
2. Center level should be the same at both ears.
3. The levels at the opposite ear should be lower, and they don’t matter. That’s Inter-Aural Level Difference, and that’s to be expected.
4. Levels should be measured with (an approximation of) HRTF, and microphones in the respective ears … NOT with a single mic pointing up in unobstructed free space.

Lacking the funds for a Neumann head ... here's a cork head with silicone ears and the Sonicpresence SP15C binaural microphones ... one in each ear ...



Initial measurements support the hypothesis. Initial listening tests are positive. More comprehensive testing today.

Thoughts? Questions? Suggestions?

[ttocs]

May 21, 2023 9:06:09 GMT -5 marcl said:

More quirks ... the Input thing at the bottom right of Measure seems to just open the ASIO4ALL section of Preferences, and it seems to work the same.  I can select channel 1 for the first input and channel 2 for the second input. But if I select channel 2 for the first input, it will only let me have channel 2 for the second input.

Exactly the same as I get when using two mics. If MicA is selected for the first input MicB is allowed to be selected for the second input, the the inverse doesn't work. If MicB is selected for input 1, MicA cannot be selected at all.

[marcl]

Okay!   I have done a complete set of measurements and corrections using this process with the Sonicpresence SP15C and sanity check with UMIK-1.  Everything measured as expected, with ear to ear differences of similar magnitude.  I corrected the right side speakers to the right ear measurements and left side speakers to the left ear measurements.  86.5dbC was the target for both.  The difference in level from the UMIK-1 to the SP15C is just due to the different mic sensitivity/gain.



Observations:

1. In every case where I expected the opposite ear to measure lower, it did, and by about the same amount for each ear.
2. Notice that measuring with the UMIK-1 would have had me lower the levels of the surrounds and rears by 1 - 2db.
3. In listening tests yesterday (similar process) ... I found I could hear sound from all the speakers more distinctly, especially from the surrounds, rears and tops.

This has been an interesting first experiment using the SP15C mic.  I have other ideas, of course.  Among these is to do frequency sweeps and look at timing and phase differences from ear to ear.  The mics aren't calibrated like the UMIK-1, but I may be able to use UMIK-1 measurements to make calibration files for the SP15C.

[ttocs]

May 21, 2023 10:54:04 GMT -5 marcl said:

1. Notice that measuring with the UMIK-1 would have had me lower the levels of the surrounds and rears by 1 - 2db.
2. In listening tests yesterday (similar process) ... I found I could hear sound from all the speakers more distinctly, especially from the surrounds, rears and tops.

So, the Rears are +2dB vs what they were before using the SP15C? And are the Surrounds the same amount higher, or just +1dB?

And for the Tops, is it just the Rear Tops that are higher, or all of them?

Just trying to get a sense of things.

[marcl]

May 21, 2023 20:25:14 GMT -5 ttocs said:

May 21, 2023 10:54:04 GMT -5 marcl said:

1. Notice that measuring with the UMIK-1 would have had me lower the levels of the surrounds and rears by 1 - 2db.
2. In listening tests yesterday (similar process) ... I found I could hear sound from all the speakers more distinctly, especially from the surrounds, rears and tops.

So, the Rears are +2dB vs what they were before using the SP15C? And are the Surrounds the same amount higher, or just +1dB?

And for the Tops, is it just the Rear Tops that are higher, or all of them?

Just trying to get a sense of things.

Here are the differences, highlighted so you can see more clearly.  If I had just used the usual UMIK-1 measurements the corrections would be as highlighted in Yellow.  But instead I used each ear's measurements and the corrections for the left ear are highlighted Blue and the right ear highlighted Orange



The biggest differences are for the right surround 4 vs 2, and the left surround 3.5 vs 2.  Only .5 difference for the rear tops, and 1.5 for the rears.

The net result is very evident with good Atmos content like with the Dolby demo disc.  In particular, the track with the Japanese funk band.  Before, I never understood the drum solo ... it just sounded dull ... but now I hear that they're bouncing the drums all over the room during the solo.  I never heard that before.

Also probably a factor in this is I had done a new Dirac calibration and for the surround and top channels I pulled the right curtains over to 10KHz.  I didn't think it made that big a difference up there - given my old ears - and I figured why waste the FIR taps.  But I think I gained some brightness that I CAN now hear in the top end and that's most evident on those channels.

And ... I looked carefully at the sweeps for each channel yesterday and the differences ear to ear are most significant over 1KHz, and in every case they make sense.  Unfortunately due to levels and the high end brightness of the SP15C the timing didn't work most of the time so I can't accurately see timing or phase differences ear to ear.  Today I'm going to take a look at doing the calibration curves so I can get more accurate measurements and measure Interaural Time Difference.

[marcl]

ttocs

Here I tried to normalize the left and right measurements to see if I could make calibration files for the L/R SP15C mics from the UMIK calibration.  First I tried to get the right UMIK and right SP aligned at 200Hz, and similarly the left UMIK and left SP aligned at 200Hz.  I picked that because I would hope all the mics would respond similarly in the middle of the range.

At that point the L/R UMIK were different from each other below 20Hz, as were the L/R SP mics.  I hypothesize that while a difference between the UMIK and SP down that low is understandable, the two UMIK measurements should be identical because it's one mic measuring the two subs only, and the two SP channels should be identical because they should not differentiate direction at that low frequency, and the subs are center front and rear and should be the same at both ears.

So after all that, I came up with this ...


... and I would be very happy with this, and in fact might say all I need to do is fix them below 40Hz and the rest is close enough ... EXCEPT for how the left SP just went crazy above 2KHz.  THAT makes no sense.

So maybe what I have to do is tape the two SP mics to the tip of the UMIK and measure combined L+R with all three and see how it plays out.  

EDIT:   Now this is more like it!  I aligned the UMIK at 300-400Hz which is where the two SP channels aligned perfectly.  Before measuring, I set each SP as the input and went to Calibrate on the SPL meter.  I did their level calibrations with the SPL on my phone.  Left measured 1db higher than right.  I used the usual 90 degree cal file for the UMIK.  Then I measured L+R.  And Center.

[ttocs]

marcl if you'd like, we could do a quick Zoom sometime in the next couple evenings so I can show how to calibrate one mic to another. Even if it isn't exactly the same - which would be expected with your ear mics, it should be pretty close. And the sensitivity of the master mic is "transferred" to the mic(s) being calibrated.

It's not really difficult, and doesn't take long. But it should be later evening so all the lawn mowers are silenced. Too noisy during the day or early evening here.

[marcl]

May 22, 2023 9:31:41 GMT -5 ttocs said:

marcl if you'd like, we could do a quick Zoom sometime in the next couple evenings so I can show how to calibrate one mic to another. Even if it isn't exactly the same - which would be expected with your ear mics, it should be pretty close. And the sensitivity of the master mic is "transferred" to the mic(s) being calibrated.

It's not really difficult, and doesn't take long. But it should be later evening so all the lawn mowers are silenced. Too noisy during the day or early evening here.

Sure!   And see my edit in the previous post.  Much more consistent results.

[zdoggz]

Hi all - When using REW (Windows 10 laptop), is there a particular hdmi input or setting that I need to have set on the rmc1 in order for it to recognize more than a 2.0 signal? I have spent hours troubleshooting the drivers and cables, umik mic, etc and no matter what I do, I can’t get anything to come out of the speakers except for the L and R. I’d like to run some sweeps to check my sub frequency response. Any ideas? Attached are a couple screenshots. Note - I also tried using the Java driver instead of the asio and still have the same thing happening.

The rmc also shows pcm 2.0 as the input signal.  Even when I try to do the 7.1 speake sound tests under windows advanced configuration, it shows 7.1 speakers but I only hear the test tone with the L and R speakers. All others are silent. 

Attachments:

[marcl]

Jun 28, 2023 20:00:44 GMT -5 zdoggz said:

Hi all - When using REW (Windows 10 laptop), is there a particular hdmi input or setting that I need to have set on the rmc1 in order for it to recognize more than a 2.0 signal? I have spent hours troubleshooting the drivers and cables, umik mic, etc and no matter what I do, I can’t get anything to come out of the speakers except for the L and R. I’d like to run some sweeps to check my sub frequency response. Any ideas? Attached are a couple screenshots. Note - I also tried using the Java driver instead of the asio and still have the same thing happening.

The rmc also shows pcm 2.0 as the input signal.  Even when I try to do the 7.1 speake sound tests under windows advanced configuration, it shows 7.1 speakers but I only hear the test tone with the L and R speakers. All others are silent. 

Have you set everything up using this guide?


www.dropbox.com/s/51jpnxet3bvew2k/REW%20101%20HTS%20Current%20Version.pdf?dl=1

[zdoggz]

Yes, I have followed that and everything seemed to line up. The only issue is nothing is coming out of the speakers other than L and R.  I’m at a loss.