Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 502 - AVS Forum | Home Theater Discussions And Reviews
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Old 06-05-2015, 10:49 AM
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Quote:
Originally Posted by buckchester View Post
Yes, I do have DynamicEQ turned on when Audyssey is on.
There's your problem right there then.

When checking speaker levels (with Audyssey on) you need to disable DEQ. In fact, any time you are measuring with REW DEQ should be disabled...unless you are specifically wanting to see the effects of DEQ.

To correctly adjust speaker levels with REW:
Turn off the subwoofer
Output -30dbfs pink noise (speaker cal) from REW to each speaker individually (i.e. CH1, then CH2, then CH3, etc.)
Adjust each speaker trim until you reach 75db on REW's SPL meter
Turn the subwoofer back on and output to CH4 (LFE) using pink noise (sub cal) and adjust the trim to 85db (the LFE channel outputs 10db higher than the rest)



Quote:
Originally Posted by gadgtfreek View Post
Not confused, just didn't explain it the way I meant it in my head, or to your liking obviously.
Nothing personal, but this statement is absolutely incorrect...doesn't matter if I like it or not.

Quote:
Audyssey boosts the LFE channel 10db when on
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Old 06-05-2015, 11:28 AM
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I have conducted some tests this morning in order to try and clear up the confusion regarding measurement headroom and microphone setting. Specifically, why are some of us able to measure at higher levels than others without clipping?

The settings/configuration for the testing was:

- AVR set to stereo mode, all trims set to zero
- REW signal is being output to Left+Right+Subs
- Using UMIK-1, 12dB sensitivity, with CSL 90-degree calibration file, "Sens Factor =-6.352dB"
- UMIK-1 in Windows set to 24-bit, 48000Hx (only choice)
- RealTek HDMI Output set to 16-bit 48000Hz (my system has no 24-bit option, don't think it matters)

For the initial set-up, I opened the REW signal generator and output a Pink Noise Sub calibration tone at -12dBFS (same level as the REW measurement sweeps). Using the REW SPL meter, I adjusted the AVR master volume so that the SPL meter was registering 90dB. This is the "desired level" for my measurement sweeps. On my system, the AVR MV value of -15 achieved the desired level.

Now, for the test, I:

- Opened the Windows Input Device (UMIK-1) and varied the input level in increments of 25, from 0 to 100.
- For each value of the mic level, I ran the -12dBFS pink noise tone and observed the output level in the REW SPL meter.
- And finally, I ran a test measurement sweep, 15-20,000Hz, and observed the headroom during the sweep. The results are listed below:



Conclusions:

- The resulting output level of the measurements is consistent above a mic setting of 25. This should alleviate concerns that some of you have expressed WRT mic input levels affecting REW measurement results. As long as the mic level is 25 or higher, there is no need to worry. The REW measurement curves were identical for each of the four mic input settings, 25, 50, 75, and 100.

- The headroom is indeed sensitive to the mic input level that is set in Windows. If your input level is currently 100, you can improve headroom by approximately 3-5dB for each reduction of 25 in the mic input sensitivity. This is good news.



Finally, I conducted one more test. With mic input sensitivity set to 100, I increased the AVR MV to -9, ran a measurement sweep at a level of 95dB, and received the clipping error message. By reducing the mic input sensitivity to 50, I was able to run the same 95dB sweep with a headroom of 6.8. Problem solved! I was even able to measure at a 100dB level and still have a headroom of 1.5 (darn, that is loud!).

I encourage everyone else to run a similar set of tests in order to establish the safe operating levels for your mic and AVR. For anyone with a UMIK-1 with 18dB sensitivity, the measurements are likely to produce different results.
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Old 06-05-2015, 11:36 AM
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Quote:
Originally Posted by Alan P View Post
There's your problem right there then.

When checking speaker levels (with Audyssey on) you need to disable DEQ. In fact, any time you are measuring with REW DEQ should be disabled...unless you are specifically wanting to see the effects of DEQ.

To correctly adjust speaker levels with REW:
Turn off the subwoofer
Output -30dbfs pink noise (speaker cal) from REW to each speaker individually (i.e. CH1, then CH2, then CH3, etc.)
Adjust each speaker trim until you reach 75db on REW's SPL meter
Turn the subwoofer back on and output to CH4 (LFE) using pink noise (sub cal) and adjust the trim to 85db (the LFE channel outputs 10db higher than the rest)

Keep in mind that the AVR speaker level-setting test tones are output without the Audyssey filters. Audyssey filters can affect the channel levels, but only 1-2dB, based on my experience. If you want to set the speaker levels properly, the Audyssey filters need to be on. I use a much easier way to test/adjust speaker levels.

It requires an external test disk with speaker test tones. I use Spears&Munsil Ver 2. Play the test tones with Audyssey on, DEQ and Dynamic Volume off, and measure the output using the REW SPL meter. Adjust all channels to read 75dB at the MLP. (Adjust subwoofer higher, depending on preference).

I have normally found the levels, when measured in this manner, to be quite close to 75dB without any manual adjustment, including the sub channel.
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Old 06-05-2015, 12:47 PM
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The REW Guide has been updated.


Updates in the Version 4.0, dated June 5, 2015 are:

- Re-worked the section on setting microphone levels in Windows audio (p. 23).
- Added a section on setting the proper measurement level before running measurement sweeps (p. 59).
- Added a section titled “Generating Distortion Graphs”.
- Various minor clean-up (e.g. new ASIO4ALL SW revision).

The guide can be viewed here.

Edited to comment: No update on Group Delay graphs. I am not comfortable enough to add a section on this topic quite yet.

Last edited by AustinJerry; 06-05-2015 at 12:53 PM.
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Old 06-05-2015, 01:56 PM
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90dB is an awfully loud target & is 15dB over what the REW docs (as well as practically everything else around) advises. FWIW I've been using REW for 10yrs and I *never* measure at those levels unless I'm doing compression sweeps. This is essentially saying that an intro guide is advising the use of hearing protection just to measure your room. Bit extreme really.

I understand you advise this for waterfalls, which is debateable but still, but waterfalls are not, I would argue, the common reason to use REW. Therefore recommend a higher level sweep for a particular reason but it shouldn't be the default recommendation.
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Old 06-05-2015, 02:31 PM
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Quote:
Originally Posted by 3ll3d00d View Post
90dB is an awfully loud target & is 15dB over what the REW docs (as well as practically everything else around) advises. FWIW I've been using REW for 10yrs and I *never* measure at those levels unless I'm doing compression sweeps. This is essentially saying that an intro guide is advising the use of hearing protection just to measure your room. Bit extreme really.

I understand you advise this for waterfalls, which is debateable but still, but waterfalls are not, I would argue, the common reason to use REW. Therefore recommend a higher level sweep for a particular reason but it shouldn't be the default recommendation.
Perhaps I should tweak the wording, although I don't find 90dB that loud. I want to take one set of measurements, and 90dB seems to be a reasonable target for anything I might want to generate down the road. Your input is appreciated as always, Matt.
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Old 06-05-2015, 02:56 PM
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I plan on unboxing my USB UMIK-1 this weekend and playing around. If I am understanding this correctly, there is absolutely no reason for me to change my UMIK from 18dB sensitivity down to 12dB sensitivity and modify the cal file? If I need more headroom, I can just turn windows volume down to 50%...or perhaps just start at 50%.
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Old 06-05-2015, 03:22 PM
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If the volume control is set to 100% when using a UMIK it applies 24 dB of digital gain. It is best used at the unity (0 dB) gain setting, for Windows 8 that is 52%, for Win7 and XP try 10%. At unity gain a UMIK with the gain switches set for 18 dB has a max input of approx 100 dB before it clips. For Win7 and later you can switch the Windows volume control to displaying dB by right clicking on it.

Last edited by JohnPM; 06-06-2015 at 01:43 AM. Reason: Corrected typo in first line, 24 dB gain is at 100% volume control setting
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Old 06-05-2015, 03:43 PM
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^^^

Listen to @JohnPM ...he created this awesome software!
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Old 06-05-2015, 03:43 PM
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Quote:
Originally Posted by JohnPM View Post
If the volume control is set to 10% when using a UMIK it applies 24 dB of digital gain. It is best used at the unity (0 dB) gain setting, for Windows 8 that is 52%, for Win7 and XP try 10%. At unity gain a UMIK with the gain switches set for 18 dB has a max input of approx 100 dB before it clips. For Win7 and later you can switch the Windows volume control to displaying dB by right clicking on it.
John - does the same apply for a UMM-6?
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Old 06-05-2015, 05:15 PM
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Quote:
Originally Posted by JohnPM View Post
If the volume control is set to 10% when using a UMIK it applies 24 dB of digital gain. It is best used at the unity (0 dB) gain setting, for Windows 8 that is 52%, for Win7 and XP try 10%. At unity gain a UMIK with the gain switches set for 18 dB has a max input of approx 100 dB before it clips. For Win7 and later you can switch the Windows volume control to displaying dB by right clicking on it.
Did you mean to type 100% in your first sentence?
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Old 06-05-2015, 09:00 PM
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Quote:
Originally Posted by AustinJerry View Post
- The headroom is indeed sensitive to the mic input level that is set in Windows. If your input level is currently 100, you can improve headroom by approximately 3-5dB for each reduction of 25 in the mic input sensitivity. This is good news.



Finally, I conducted one more test. With mic input sensitivity set to 100, I increased the AVR MV to -9, ran a measurement sweep at a level of 95dB, and received the clipping error message. By reducing the mic input sensitivity to 50, I was able to run the same 95dB sweep with a headroom of 6.8. Problem solved! I was even able to measure at a 100dB level and still have a headroom of 1.5 (darn, that is loud!).

I encourage everyone else to run a similar set of tests in order to establish the safe operating levels for your mic and AVR. For anyone with a UMIK-1 with 18dB sensitivity, the measurements are likely to produce different results.
Hi, I can add that similar approach works in Mac OS X , I had similar issues with clipping for compression sweeps and Alan P. recommended changing mic input sensativity. It work very similarly as to what you described above. That was with UMIK-1 with 18dB sendsitivity.

One difference is that on Mac , mic input sensitivity of 1.0 corresponds to 100 in Windows, so I decreased to 0.50 (aka 50%) with increase in Headroom and resolution of clipping issues allowing sweep up to 104 dB.

Change is the only constant.

My HT: http://www.avsforum.com/forum/19-ded...l#post32691273
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Old 06-05-2015, 09:09 PM
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Quote:
Originally Posted by AustinJerry View Post
I have conducted some tests this morning in order to try and clear up the confusion regarding measurement headroom and microphone setting. Specifically, why are some of us able to measure at higher levels than others without clipping?

The settings/configuration for the testing was:

- AVR set to stereo mode, all trims set to zero
- REW signal is being output to Left+Right+Subs
- Using UMIK-1, 12dB sensitivity, with CSL 90-degree calibration file, "Sens Factor =-6.352dB"
- UMIK-1 in Windows set to 24-bit, 48000Hx (only choice)
- RealTek HDMI Output set to 16-bit 48000Hz (my system has no 24-bit option, don't think it matters)

For the initial set-up, I opened the REW signal generator and output a Pink Noise Sub calibration tone at -12dBFS (same level as the REW measurement sweeps). Using the REW SPL meter, I adjusted the AVR master volume so that the SPL meter was registering 90dB. This is the "desired level" for my measurement sweeps. On my system, the AVR MV value of -15 achieved the desired level.

Now, for the test, I:

- Opened the Windows Input Device (UMIK-1) and varied the input level in increments of 25, from 0 to 100.
- For each value of the mic level, I ran the -12dBFS pink noise tone and observed the output level in the REW SPL meter.
- And finally, I ran a test measurement sweep, 15-20,000Hz, and observed the headroom during the sweep. The results are listed below:



Conclusions:

- The resulting output level of the measurements is consistent above a mic setting of 25. This should alleviate concerns that some of you have expressed WRT mic input levels affecting REW measurement results. As long as the mic level is 25 or higher, there is no need to worry. The REW measurement curves were identical for each of the four mic input settings, 25, 50, 75, and 100.

- The headroom is indeed sensitive to the mic input level that is set in Windows. If your input level is currently 100, you can improve headroom by approximately 3-5dB for each reduction of 25 in the mic input sensitivity. This is good news.



Finally, I conducted one more test. With mic input sensitivity set to 100, I increased the AVR MV to -9, ran a measurement sweep at a level of 95dB, and received the clipping error message. By reducing the mic input sensitivity to 50, I was able to run the same 95dB sweep with a headroom of 6.8. Problem solved! I was even able to measure at a 100dB level and still have a headroom of 1.5 (darn, that is loud!).

I encourage everyone else to run a similar set of tests in order to establish the safe operating levels for your mic and AVR. For anyone with a UMIK-1 with 18dB sensitivity, the measurements are likely to produce different results.
Thank you so much for this Jerry. It really clears up a lot of the confusion.

What operating system are you using? According to this post from JohnM Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs it seems that affects the ideal mic input level to set (to reach unity gain), if that matters? I say "if that matters" because he does say its best to set it at unity gain but I'm not sure why and how much it matters if its not.
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Old 06-05-2015, 09:23 PM
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Quote:
Originally Posted by JohnPM View Post
...For Win7 and later you can switch the Windows volume control to displaying dB by right clicking on it.
By clicking on what, the sound icon in the system tray? When I right click on that it just brings up a menu of options.
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Old 06-06-2015, 01:46 AM
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Quote:
Originally Posted by Alan P View Post
John - does the same apply for a UMM-6?
I think the UMM-6 gain range is +12 dB at 100% down to -18 dB at 0, but best way to check is to set the volume control to display dB.
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Old 06-06-2015, 01:46 AM
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Originally Posted by Soulburner View Post
Did you mean to type 100% in your first sentence?
Yes, fixed that, thanks.
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Old 06-06-2015, 01:50 AM
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Quote:
Originally Posted by lovingdvd View Post
By clicking on what, the sound icon in the system tray? When I right click on that it just brings up a menu of options.
By right clicking on the volume control.

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Old 06-06-2015, 03:38 AM
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Is there any way we can confirm when we're at "unity gain"?
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Old 06-06-2015, 04:59 AM
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Originally Posted by Soulburner View Post
Is there any way we can confirm when we're at "unity gain"?
Unity=100%. Is that what you are asking?
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Old 06-06-2015, 05:00 AM
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Quote:
Originally Posted by lovingdvd View Post
Thank you so much for this Jerry. It really clears up a lot of the confusion.

What operating system are you using? According to this post from JohnM Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs it seems that affects the ideal mic input level to set (to reach unity gain), if that matters? I say "if that matters" because he does say its best to set it at unity gain but I'm not sure why and how much it matters if its not.
I am using Windows 7 32-bit on my REW laptop.
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Old 06-06-2015, 05:02 AM
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Quote:
Originally Posted by sinisanav View Post
Hi, I can add that similar approach works in Mac OS X , I had similar issues with clipping for compression sweeps and Alan P. recommended changing mic input sensativity. It work very similarly as to what you described above. That was with UMIK-1 with 18dB sendsitivity.

One difference is that on Mac , mic input sensitivity of 1.0 corresponds to 100 in Windows, so I decreased to 0.50 (aka 50%) with increase in Headroom and resolution of clipping issues allowing sweep up to 104 dB.
Thanks for the report. It's nice to hear that things work in a similar manner on the Mac.

Last edited by AustinJerry; 06-06-2015 at 08:58 AM.
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Old 06-06-2015, 07:39 AM
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Here is my latest run after swapping out one of my subs

4 different sub modes tested (I chose the green mode as the keeper)


Subs and 3 front speakers


At the suggestion of some sub owners I will try checking the sub with the xover higher to see where it and the speakers naturally roll off (XT32 off) to see where they all blend together.

One question. Part of the process I have been doing is I run XT32. I then put in a test blu-ray with -30dbfs pink noise and -40dbfs pink noise and checking my levels for 75db at reference volume. Is the SPL meter in REW coupled with the Umik-1 suitable for this (downloaded and used sensitivity number from Minidsp per my serial number), or would you recommend a "verified" CM140 from Cross Spectrum. I have found, with the umik, that XT32 is usually right on with the speakers, but not always with the subs (usually 1 to 5 db low depending on the run).

Thanks.


PS: I have a Umik with -18 gain, I think I will reduce the master volume for the mic in windows to be 0.0db, or 52% depending on how you look at it. I can't go louder than -15db on the preamp right now without clipping.


Last edited by gadgtfreek; 06-06-2015 at 07:45 AM.
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Old 06-06-2015, 07:45 AM
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Originally Posted by gadgtfreek View Post
...At the suggestion of some sub owners I will try checking the sub with the xover higher to see where it and the speakers naturally roll off (XT32 off) to see where they all blend together...
Can you (or someone) explain more about how to perform this process to determine where the speakers and sub naturally roll off? Sounds very useful. I presume this then gives a good indication of where the xo should be optimally set?

BTW, regarding that -5 dB dip near around 22Hz. Am I correct to assume you are sitting near the center of your room? I could easily be mistaken here, but I believe that's what a dip in that area would imply. Have you experimented with moving your sub (ideally close to your Main Listening Position), moving your MLP, or both?
[/QUOTE]
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Old 06-06-2015, 07:54 AM
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Actually, wall to wall is 13ft or so. subs and fronts are against one wall, two chairs against the other wall, right up against. MLP measurement is taken on table in between the two chairs, 20" off wall and ear height. To the left of our chairs is a wall, and to the right of us it opens into a "T" with a dining room on one side and a kitchen on the other. Ceiling is about 14feet and whole area is around 5400cuft. I do not have any options for moving the MLP and the subs, kinda is what it is... The dip got better when I sold one VTF15 and added the Rythmik. I hope to add another Ryhtmik in the next 30 days and sell the other VTF15. Maybe it will help (or not ).

As far as the raw sweep, here is what I was told in another thread:

Quote:
Would like to see the raw response. I.e NO Audyssey. Be sure to set the crossover to 250Hz so the upper extension of the subs can be recorded.

The purpose of running the raw graphs for each of the fronts is to check where the roll off starts in your room and compare that to what the speaker manufacturer recommends the -3dB point to be.

The same thing for the subs, but at the high end.

You want to be able to crossover in the sweet spot where there is sufficient overlap of the fronts and subs so that it gives you maximum flexibility in the crossover setting for individual or overall.
I also need to dive deeper into waterfalls now that I am starting to learn the basics of REW.
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Old 06-06-2015, 03:50 PM
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Quote:
Originally Posted by AustinJerry View Post
Unity=100%. Is that what you are asking?
Not for the UMIK interface, unity gain = 0 dB which is at about 52% on the volume control.
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Old 06-06-2015, 04:54 PM
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Umik-1 gain change

Hello,
If anyone is interested I changed my UMIK's gain from 18dB to 12dB and checked to make sure nothing was altered. The 18dB gain mic has the dip switches in the off on on position. To change this put the switches in the on off off position. If you look at the switches you will see at the bottom the dip switch numbers of 1 2 and 3 and above this is (ON) in very small letters. I had to use a magnifier to see any of this. I used needle nose tweezers to open the mic up, counter-clock wise to open.

Before changing my gain on the UMIK I did a test compliments of Jerry who was so gracious to help me. Still with 18dB gain I launched REW and using the signal generator I output a test tone (pink noise) and adjusted my MV so that the mic was reading (with the SPL meter in REW) a specific value (80 dB), a side note I output the signal with -12dBFS and wrote down the MV for this 80dB SPL which was -18 on the receiver.

I then changed the mic's gain to 12dB and then changed my cal file by subtracting -6 db to the SENS FACTOR which originally was =0.6814dB, to this value =-5.3186dB,
This is what it looked like prior to changing "Sens Factor =0.6814dB, SERNO: 7005070"
and after the change was this "Sens Factor =-5.3186dB, SERNO: 7005070" You don't have to change the whole thing, just highlight =0.6814dB, and put the new value in =-5.3186dB, . I have a UMIK from miniDSP.

I then performed the exact same test with the mic at 12dB gain and set my MV at -18 on AVR and used REW's SPL meter and the output was exactly he same (80dB) output on the REW meter.

Sorry for the long winded post but if I can do this anyone can..

Jerry, I did the test to check how accurate the UMIK was when the sensitivity parameter is being used as a substitute for an actual mic calibration, I placed the RS SPL meter very close to my left front speaker and used REW's signal generator to output a 1kHz tone at -20 dB FS and adjusted the MV until it read 70dB. I then did the same thing with the UMIK placed right next to the RS meter and got the same 70 dB reading (it was actually 1 db off ).

I was very pleased to know the REW SPL meter was that close (-1dB) to the RS meter meaning that the sensitivity parameter is providing accurate results.. I then wanted to check the results when the input volume was changed and what impact it would have on the mic's calibration. I couldn't find "Control Mixer Input/Volume" box to change it. When I switch to Java driver it becomes available. What am I missing here? TIA

I hope this was helpful to someone, I was very reluctant to try the mic gain change but it turned out to be a lot easier than I thought.

Cheers Jeff
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Old 06-06-2015, 05:25 PM
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Originally Posted by ahblaza View Post

I hope this was helpful to someone, I was very reluctant to try the mic gain change but it turned out to be a lot easier than I thought.

Cheers Jeff
Nice job, Jeff, thanks for sharing your experiences. I think we are closer to understanding the USB mic gain, headroom, etc. after this week's efforts, and after JohnPM's useful posts.

I need to tweak the Guide based on the recent findings.
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Old 06-06-2015, 05:39 PM
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Hello,
If anyone is interested I changed my UMIK's gain from 18dB to 12dB and checked to make sure nothing was altered. The 18dB gain mic has the dip switches in the off on on position. To change this put the switches in the on off off position. If you look at the switches you will see at the bottom the dip switch numbers of 1 2 and 3 and above this is (ON) in very small letters. I had to use a magnifier to see any of this. I used needle nose tweezers to open the mic up, counter-clock wise to open.

Before changing my gain on the UMIK I did a test compliments of Jerry who was so gracious to help me. Still with 18dB gain I launched REW and using the signal generator I output a test tone (pink noise) and adjusted my MV so that the mic was reading (with the SPL meter in REW) a specific value (80 dB), a side note I output the signal with -12dBFS and wrote down the MV for this 80dB SPL which was -18 on the receiver.

I then changed the mic's gain to 12dB and then changed my cal file by subtracting -6 db to the SENS FACTOR which originally was =0.6814dB, to this value =-5.3186dB,
This is what it looked like prior to changing "Sens Factor =0.6814dB, SERNO: 7005070"
and after the change was this "Sens Factor =-5.3186dB, SERNO: 7005070" You don't have to change the whole thing, just highlight =0.6814dB, and put the new value in =-5.3186dB, . I have a UMIK from miniDSP.

I then performed the exact same test with the mic at 12dB gain and set my MV at -18 on AVR and used REW's SPL meter and the output was exactly he same (80dB) output on the REW meter.

Sorry for the long winded post but if I can do this anyone can..

Jerry, I did the test to check how accurate the UMIK was when the sensitivity parameter is being used as a substitute for an actual mic calibration, I placed the RS SPL meter very close to my left front speaker and used REW's signal generator to output a 1kHz tone at -20 dB FS and adjusted the MV until it read 70dB. I then did the same thing with the UMIK placed right next to the RS meter and got the same 70 dB reading (it was actually 1 db off ).

I was very pleased to know the REW SPL meter was that close (-1dB) to the RS meter meaning that the sensitivity parameter is providing accurate results.. I then wanted to check the results when the input volume was changed and what impact it would have on the mic's calibration. I couldn't find "Control Mixer Input/Volume" box to change it. When I switch to Java driver it becomes available. What am I missing here? TIA

I hope this was helpful to someone, I was very reluctant to try the mic gain change but it turned out to be a lot easier than I thought.

Cheers Jeff
Thanks Jeff. So what would you say you can conclude from your testing? Seemed like a lot of work to prove the SPL would measure the same. Are there any other takeaways or implications for using REW with gain of 12 vs 18?

Yes I too measured only a 1 dB difference between The UMIK-1 and RS analog meter.
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Old 06-06-2015, 06:00 PM
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Thanks Jeff. So what would you say you can conclude from your testing? Seemed like a lot of work to prove the SPL would measure the same. Are there any other takeaways or implications for using REW with gain of 12 vs 18?

Yes I too measured only a 1 dB difference between The UMIK-1 and RS analog meter.
@Jerry , thank you and you're welcome my friend. At first I thought there would be a bigger advantage going with the 12 dB gain instead of the 18, plus the fact I wanted to prove to myself that I could do it, everything about REW has intimidated me for a long time until I down loaded Jerry's guide and spent countless hours going through the posts on this thread.

I just jumped in and starting taking measurements. Now that Jerry has done the tests with the mic input volume from 0 25 50 and 100 and showed that it's really not necessary to change the the sensitivity of your mic. I guess when I become brave enough I will start posting some of my graphs and hopefully they will correlate with others using the 12dB gain structure. As far as implications I don't see any.........
Jeff
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Old 06-06-2015, 07:14 PM
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Unity=100%. Is that what you are asking?
No, according to John there are volume levels that achieve "unity gain", and they apparently vary according to your OS, but I'm asking if there is a way we can verify if we are in fact at that ideal level. It is not apparent.

Edit - just saw this post:

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Originally Posted by JohnPM View Post
Not for the UMIK interface, unity gain = 0 dB which is at about 52% on the volume control.

Last edited by Soulburner; 06-06-2015 at 07:19 PM.
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