Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 375 - AVS Forum
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post #11221 of 12239 Old 08-27-2014, 09:44 AM
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I just created a new thread for the file size data discrepancy issue.

http://www.hometheatershack.com/foru...tml#post892377

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post #11222 of 12239 Old 08-27-2014, 09:57 AM
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Lots of help offered here--thank you. I don't have time right now for a proper response, but will draw one up when I have the time.

The coles notes of what I found last night--using two different sets of FS pink noise on CD using two different sources (DVD & Blu-ray player both feeding different HDMI inputs on my AVR with "stereo" as the listening mode) the levels agree with what I'm seeing when calibrated via REW within 1 dB.

The AVR's sub signal does not agree with REW, or the various test tones on CD. It is quite a bit higher. Not 10dB, but like I said--I'll write out the whole process in greater detail. Thanks!
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post #11223 of 12239 Old 08-27-2014, 10:41 AM
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Quote:
Originally Posted by Alan P View Post
Hey HD - do you calibrate the SPL in REW every session or do you have a mic cal file with a sensitivity factor? Which mic again?

If the former, maybe your SPL meter is whack. If the latter, maybe your cal file is whack.

Just trying to help.
Quote:
Originally Posted by AustinJerry View Post
First of all, if REW detects a sensitivity parameter in the calibration file, it won't let you manually calibrate the mic. When you click the Calibrate button, you will get a pop-up message stating that calibration is not necessary.
I should be more careful with my language. What I meant to say was I use a UMIK-1 for all my measurements. It came with a calibration file (with sensitivity settings) that I have loaded into REW. When I say I set levels every time, what I meant was I ensure I have the same volume (SPL) before performing any work / sweeps. I do not re-calibrate the mic. The calibration as it were, is automatic. I have not verified the sensitivity setting as the only other SPL meter I have is an iPhone app, and I don't trust it with the iPhone's internal microphone (all I have at the moment).
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post #11224 of 12239 Old 08-27-2014, 10:49 AM
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Quote:
Originally Posted by HDgaming42 View Post
...the only other SPL meter I have is an iPhone app, and I don't trust it with the iPhone's internal microphone (all I have at the moment).
Those dB apps will get you within 10dB that's for sure! Seriously though, they're better than you think.
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post #11225 of 12239 Old 08-27-2014, 11:00 AM
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Thank you for this detailed walkthrough. I will tell you how my process so far (what I have done prior to you providing this breakdown) has deviated from yours, and whether you think that would constitute the difference I'm seeing.

Quote:
Originally Posted by AustinJerry View Post
1. Set the trim in the AVR equal to zero for the left, center, right and sub channels as a starting point.
2. Set the AVR master volume to zero (we want each speaker to measure 75dB at MV=0).
3. Set main speakers and center channel to "Large" (we don't want the subs involved in the measurement of the LCR speakers).
I did not do this and just turned the sub off.

Quote:
4. Launched REW and opened the REW SPL tool so I could measure sound output using the calibrated UMIK-1.
5. Placed the UMIK-1 in the MLP at ear height, pointed at the ceiling.
6. Opened the REW signal generator, selected Pink Noise, "Speaker Cal" output, and set the dB FS output to -30. Why -30? Because -30 was measuring close to 75dB on the REW SPL.
I used -20dB FS, and just adjusted the MV on my AVR to hit 75dB (being at MV 0 is ideal, but I don't believe necessary for these testing purposes)

Quote:
7. Played the pink noise tone for the left channel, and adjusted the speaker trim until the REW SPL was showing 75dB.
8. Played the pink noise tone for the right channel, and adjusted the speaker trim until the REW SPL was showing 75dB.
9. Repeated the process for the center channel, adjusting the trim so I was reading 75dB on the REW SPL. At this point, the left, right, and center output levels are the same.
I adjusted the gain pots on my speakers, as opposed to the trim setting on the AVR to allow a finer adjustment later via the AVR if necessary.

Quote:
10. Changed the LCR speakers back to "small" so bass is routed to the subs.
I never set them to Large so I didn't do this.

Quote:
11. Turned off the LCR speakers so only the subs were playing.
12. Changed the signal generator to output the "Sub Cal" signal.
13. Played the pink noise tone and adjusted the combined sub output so I was reading 75dB on the REW SPL. Now the sub channel level is the same as the LCR.
Are you saying you adjusted the trim in the AVR so that your four subs dropped to 75dB while all playing simultaneously, or that you adjusted each sub manually (at the sub) while they were playing simultaneously to hit 75dB?

Quote:
Observations:

- I believe I have demonstrated that REW can be used to set speaker levels accurately.
- The sub channel level is exactly the same as the level set by using the AVR internal test tones, i.e. no 10dB difference betwee the two approaches.
- Letting Audyssey set the trims is considerably easier, and just as accurate, if not more accurate.
Could that observation be accurately summarized as "your AVRs test tones appear to match REWs"? I suspect my AVR does not--as I will outline in my upcoming post regarding level differences.

My methodology and yours are, in my opinion, damn near the same. I could somewhat suspect my installation / configuration of ASIO4ALL, but believe I have ruled that out with my subsequent testing of CD based test tones...

Quote:
Edit: Now that I think about it, I believe "Reference Level" is 105dB at the MLP with master volume at zero. So setting the signal generator to output -30 dB FS to produce 75db at the MLP with MV=0 sounds logical.
This math confuses me. Is it because "Reference Level" is assuming all speakers are playing? It is additive? How can 75dB at the MLP at MV=0 be the same as 105dB at the MLP at MV=0?
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post #11226 of 12239 Old 08-27-2014, 11:05 AM
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Quote:
Originally Posted by HDgaming42 View Post
This math confuses me. Is it because "Reference Level" is assuming all speakers are playing? It is additive? How can 75dB at the MLP at MV=0 be the same as 105dB at the MLP at MV=0?
see an earlier post in this thread - Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs
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post #11227 of 12239 Old 08-27-2014, 11:49 AM
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Testing internal AVR test tones vs REW vs CD

Here was my methodology.

1. Set the trim in the AVR equal to zero for the left, center, right and sub channels as a starting point.
2. Set all speakers to cross over at 80Hz. Set sub LPF to 120Hz. Shut off sub.
3. Launched REW and opened the REW SPL tool so I could measure sound output using the calibrated UMIK-1.
4. Placed the UMIK-1 in the MLP at ear height, pointed at the ceiling.
5. Set my AVR to "stereo" mode.
6. Played the internal AVR pink noise for L. This disables my volume control. I adjusted the gain on the L monitor so that it was reading as close to 75dB as possible (73.6dB) using the small gain dial.
7. I then adjusted my iPhone SPL meter to also read 73.6dB, slow C weighted.
8. I turn off the L monitor, turn on the sub and play the AVR pink noise for the sub.
9. I adjusted the sub volume knob to read as close to 73.6dB as I could via the REW SPL meter. I had a choice of either 75.5dB, or 72.4dB. I chose the former (and later test with the later).
10. The iPhone app at this point reads 64.5dB for the sub. Well worth that $4.

Can we agree that at this point, my sub should be level matched (within a few dB) to my L channel? At least according to the AVR?

Now to compare to REW.

11. Opened the REW signal generator, selected Pink Noise, "Full Range" output, and set the dB FS output to -20.
12. Set output to Channel 1 & Channel 2. Turned off the sub, turned on L channel.
13. Played the full range pink noise tone and raised the AVR main volume until REW SPL was showing 75dB.
14. Verified the AVR was seeing 2 channel PCM and set to "stereo".
15. Turned off the L speaker and turned on the sub.
16. Played the full range pink noise tone again and found the sub was reading 79dB in REW, and 64.4 on the iPhone.

Hmmm.

Burned a CD containing two FS pink noise tones, one from the realtraps test tone Cd, and the other from the Blue Sky test tone CD (which I know was recorded at -20dB FS).

Played them through my oppo 970HD, adjusting main volume of the left to be 73.6dB and then comparing to what the sub read.
Found a discrepancy again.
Don't trust my oppo as I've never really found it's audio setup to be very user friendly.

17. Switched out to my Sony Blu-ray, which outputs raw PCM for CDs.
18. Verified that is what the AVR was seeing.
19. Adjusted volume on the AVR so that L was reading 73.6dB for the blue skies tone. AVR volume was then -8.5.
20. Sub then read 78.9dB and iPhone read 64dB.
21. Tried the real traps tone and set L to read 73.6dB in REW.
22. AVR volume was then -14.5.
23. Sub read 80dB and iPhone read 64.5dB.

AVR and test tone CD do not agree.

So here we have the following

AVR sets L at 73.6dB and Sub at 75.5dB.
Cross referenced with REW L is 73.6dB and Sub is 79dB (+3.5).
Cross referenced with Realtraps L is 73.6dB and Sub is 80dB (+4.5).
Cross referenced with Blue Skies L is 73.6dB and Sub is 78.9dB (+3.4).

In all these cases the sub is high, so I redid the initial AVR setting and chose 72.4 (next volume notch down) and repeated this procedure with REW, omitting the test tone CD as it agrees quite closely with REW. This is what I found:

AVR sets L at 73.6dB and Sub at 72.4dB.
Cross referenced with REW L is 73.6dB and Sub is 76.4dB (+4.0).

This mirror's quite closely the smoothed response I posted earlier between my AVR and REWs settings, which I was eyeballing as a 5dB difference.

Which is more likely in this scenario? I am screwing up something in what I have listed above, or my AVR does not output an accurate sub pink noise signal? I'm leaning toward the later.

I tried the RTA method and it had me land up exactly where REW's full range pink noise signal had me set the subwoofer level.

Last edited by HDgaming42; 08-27-2014 at 11:53 AM.
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post #11228 of 12239 Old 08-27-2014, 12:04 PM
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One difference is that you are comparing band limited pink noise played directly to the sub vs full bandwidth pink noise played to a bass managed main channel.

The sub cal signal would be more akin to the avr sub tone. Band limited pink noise puts less energy into the room than full bandwidth and you may also be activating some room modes more aggressively with a full bandwidth signal (you don't mention room size so unsure if this is the case), both of these can elevate the levels measured on an SPL meter.

If you use band limited noise then no need to switch off devices BTW.

I still don't know why you are using the gain on your speakers to control levels though.
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post #11229 of 12239 Old 08-27-2014, 12:56 PM
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Quote:
Originally Posted by HDgaming42 View Post
This math confuses me. Is it because "Reference Level" is assuming all speakers are playing? It is additive? How can 75dB at the MLP at MV=0 be the same as 105dB at the MLP at MV=0?
http://www.acousticfrontiers.com/hom...eference-level

Markus

"In science, contrary evidence causes one to question a theory. In religion, contrary evidence causes one to question the evidence." - Floyd Toole
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post #11230 of 12239 Old 08-27-2014, 01:41 PM
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Quote:
Originally Posted by HDgaming42 View Post

This math confuses me. Is it because "Reference Level" is assuming all speakers are playing? It is additive? How can 75dB at the MLP at MV=0 be the same as 105dB at the MLP at MV=0?
You have received several good responses already to this question. To say it in my own words, if the MV=0, a signal played at 0 dB FS will measure 105dB. To get the signal down to 75 dB, which is the level you want to use to set the speaker trims, you lower the test signal level by 30 dB (105-30=75), i.e. the test signal should be set to play at -30 dB FS.
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post #11231 of 12239 Old 08-27-2014, 01:43 PM
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@hdgaming : thank you for taking the time to explain what you are doing in such detail. I plan on setting up REW later this afternoon and running some tests before I respond to your post. I want to make sure of what I have to say before proceeding. I think we are getting very close to resolving this whole issue. When we are all in agreement, I think we have enough information to add a new section to the Guide, "How to use REW to set speaker levels".
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post #11232 of 12239 Old 08-27-2014, 01:53 PM
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Quote:
Originally Posted by 3ll3d00d View Post
One difference is that you are comparing band limited pink noise played directly to the sub vs full bandwidth pink noise played to a bass managed main channel.

The sub cal signal would be more akin to the avr sub tone. Band limited pink noise puts less energy into the room than full bandwidth and you may also be activating some room modes more aggressively with a full bandwidth signal (you don't mention room size so unsure if this is the case), both of these can elevate the levels measured on an SPL meter.

If you use band limited noise then no need to switch off devices BTW.

I still don't know why you are using the gain on your speakers to control levels though.
I'm going off memory here, so it is certainly fallible, but I started this whole process using "speaker cal" for my monitors and "sub cal" for my sub until I was (erroneously) informed that the "sub cal" signal had a difference of 10dB. It was at that point I switched over to "full range" and let bass management do its thing.

Using "sub cal" I thought I was seeing a 10dB difference between AVR and REW. I will repeat with speaker and sub cal respectively and post my results, assuming no one points out any flaws in my above methodology.

My room is 196" by 120" by 88", so room modes are certainly an issue.

Is there a reason not to use the monitor gains? There is no "detent" position, so I figure playing a known tone and then adjusting them that way without involving the AVR is the best first step. I want to hand things off to the AVR in the best condition possible. Using the gains allows the AVR more latitude with it's automated trim functions +/-. At least that's my theory.

I'm following the following loose workflow 1. placement of MLP 2. placement of speakers 3. setting levels / crossovers 4. tweaking treatments 5. engaging Audyssey 6. tweaking Audyssey results if necessary with a miniDSP*

*my Audyssey is only MultiEQ XT with the terrible Onkyo puck mic.

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Originally Posted by markus767 View Post
Thanks--I will look into this.
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post #11233 of 12239 Old 08-27-2014, 01:58 PM
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Quote:
Originally Posted by HDgaming42 View Post
Is there a reason not to use the monitor gains? There is no "detent" position, so I figure playing a known tone and then adjusting them that way without involving the AVR is the best first step. I want to hand things off to the AVR in the best condition possible. Using the gains allows the AVR more latitude with it's automated trim functions +/-. At least that's my theory.
I've been assuming they are active & that the gain dial on there controls input sensitivity hence you want to set that so that they are near clipping at max *input* signal level (typically reference unless you like to play *really* loud). You then adjust the trims in the AVR to level match.

I could be wrong of course so the Q remains, which monitors are they exactly?
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post #11234 of 12239 Old 08-27-2014, 02:07 PM
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Quote:
Originally Posted by 3ll3d00d View Post
I've been assuming they are active & that the gain dial on there controls input sensitivity hence you want to set that so that they are near clipping at max *input* signal level (typically reference unless you like to play *really* loud). You then adjust the trims in the AVR to level match.

I could be wrong of course so the Q remains, which monitors are they exactly?
Mackie HR624mkII. They are the first powered monitors I've owned, and what you've described makes a lot of sense.

How would I go about setting them properly first, and then using the AVRs trims instead? I run to them via unbalanced RCA, "C" position (away from walls) and 49Hz (normal) crossover.

Apologies--they do have an "off" available on the gains. Will use that for my next round of tests until I learn how to set them properly...

Last edited by HDgaming42; 08-27-2014 at 02:18 PM.
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post #11235 of 12239 Old 08-27-2014, 02:17 PM
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Do you have a multimeter? If not, you will want some ear plugs
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post #11236 of 12239 Old 08-27-2014, 02:32 PM
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Quote:
Originally Posted by HDgaming42 View Post
Thanks--I will look into this.
Please do and please use the RTA method I've outlined above. You're wasting a ton of time (not only yours) trying to make REW sub/speaker cal work without understanding the fundamentals behind it.

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post #11237 of 12239 Old 08-27-2014, 02:56 PM
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Quote:
Originally Posted by AustinJerry View Post
@hdgaming : thank you for taking the time to explain what you are doing in such detail. I plan on setting up REW later this afternoon and running some tests before I respond to your post. I want to make sure of what I have to say before proceeding. I think we are getting very close to resolving this whole issue. When we are all in agreement, I think we have enough information to add a new section to the Guide, "How to use REW to set speaker levels".
This sounds very promising...

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Originally Posted by markus767 View Post
Please do and please use the RTA method I've outlined above. You're wasting a ton of time (not only yours) trying to make REW sub/speaker cal work without understanding the fundamentals behind it.
I think I've wrapped my head around that link and now understand why to use -30dB FS. I'm a little lost with your RTA method though. If my response is all over the map (it looks nothing like a straight line) is it better to focus on 60Hz, 30Hz or split the difference? I'm going to try 3ll3d00d's explanation from the page prior and see what happens...
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post #11238 of 12239 Old 08-27-2014, 03:01 PM
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Turns out (when I bring enough light into that cave!) my monitors have 3 markings on them for gain. "off", which is literally off--no sound, "-10" at the top and "normal" at the far right.

I set them all to normal and then used the AVR to set the levels to reach 75dB
Left -1.5
Center -0.2
Right -2.0
Sub (set it via the volume on the back)

Using REW to generate speaker and sub cal signals, I had to use the AVR to drop the sub from 0 to -6.5 to come down to 75dB. (The L channel was at 75dB when my AVR's volume was -3)
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post #11239 of 12239 Old 08-27-2014, 03:04 PM
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Quote:
Originally Posted by 3ll3d00d View Post
I think there are (at least) 2 reasons to use REW to set levels rather than using prepro test tones

1) you can measure with EQ applied
2) you can see the results with a high resolution RTA rather than relying on a relatively crude SPL meter

This means the results can be more accurate than using the AVR + SPL meter alone. I don't see much point in using REW as a signal generator but not as the measurement device as well.
I agree completely.

Quote:
If I get time then I post an example later.
Please do if you find the time--this would be immensely helpful.
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post #11240 of 12239 Old 08-27-2014, 03:34 PM
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Quote:
Originally Posted by markus767 View Post
^
The easiest way of matching a sub to the satellites is to play full bandwidth pink noise and adjust the 30 or 60Hz band until it reads the same as the 1kHz band in an 1/1 octave RTA.

Not sure how I initially missed the 32 averaging. Looks like this RTA method is a win for team AVR internal test tones, as I arrived at -1 for sub trim, off the 0 I had.

Does this look (attached) correct? I was able to match up 60Hz, but 30Hz is out of wack...
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post #11241 of 12239 Old 08-27-2014, 03:36 PM
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Quote:
Originally Posted by HDgaming42 View Post
Turns out (when I bring enough light into that cave!) my monitors have 3 markings on them for gain. "off", which is literally off--no sound, "-10" at the top and "normal" at the far right.
without wanting to RTFM you, http://www.mackie.com/products/hrmk2...r624mk2_om.pdf

This says that normal means it is set for +4dBu operation (~1.22Vrms) and that the point you will actually clip the inputs is at +20dBu (aka 7.75Vrms). It also says that -7.5dBu (0.32Vrms) should produce 100dB at 1m. Therefore what you want to achieve, given this setup, is to produce approx 1.2Vrms on the line to your monitor when the MV is at 0 (assuming you never intend to go past 0). You can do this using REW as follows

- disconnect the speaker
- set AVR trim to 0
- set MV to 0
- ensure the channel to set to LARGE
- start the signal generator to produce a sine wave at 60Hz and -3dBFS (REW using RMS levels so a -3dBFS sinewave has peaks at 0dBFS)
- set your multimeter to measure AC voltage
- connect it to the line out and measure the voltage
- change the trim to meet the target 1.2Vrms (or you can calculate the dB change required by using 20 * log(1.22/whatever you measured)

if the trim change required is large then you may need to use the -10dB sensitivity (which will reduce the voltage required to produce full power) and repeat

if you don't have a multimeter then you need to have the speaker connected, ear plugs in to avoid going deaf and then adjust the trim til the -3dBFS sine wave doesn't activate the clip lights on your monitors.

if you are using these in a surround setup so you have speakers at different distances then you'll have to give up some headroom somewhere, i.e. either by reducing the level to the nearer speakers thus not being able to drive them to full power or increasing the level to the more distant speakers and not being able to raise the MV as far (same difference in the end).

Last edited by 3ll3d00d; 08-27-2014 at 03:39 PM.
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post #11242 of 12239 Old 08-27-2014, 03:39 PM
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So, HD, does this mean we are good now? I have my REW kit set up and have run through the procedure I posted yesterday, and AFAICT the procedure is working fine. Your speaker levels look reasonable, and the RTA graph looks reasonable at 60Hz. Are there any other outstanding questions or issues?

BTW, setting the speakers to "Large", or powering off the sub, results in the same thing. I have four subs, so powering them off and on is not as easy as a couple of mouse clicks to set the speakers to large.
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post #11243 of 12239 Old 08-27-2014, 03:42 PM
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Originally Posted by 3ll3d00d View Post
without wanting to RTFM you, http://www.mackie.com/products/hrmk2...r624mk2_om.pdf

This says that normal means it is set for +4dBu operation (~1.22Vrms) and that the point you will actually clip the inputs is at +20dBu (aka 7.75Vrms). It also says that -7.5dBu (0.32Vrms) should produce 100dB at 1m. Therefore what you want to achieve, given this setup, is to produce approx 1.2Vrms on the line to your monitor when the MV is at 0 (assuming you never intend to go past 0). You can do this using REW as follows

- disconnect the speaker
- set AVR trim to 0
- set MV to 0
- ensure the channel to set to LARGE
- start the signal generator to produce a sine wave at 60Hz and -3dBFS (REW using RMS levels so a -3dBFS sinewave has peaks at 0dBFS)
- set your multimeter to measure AC voltage
- connect it to the line out and measure the voltage
- change the trim to meet the target 1.2Vrms (or you can calculate the dB change required by using 20 * log(1.22/whatever you measured)

if the trim change required is large then you may need to use the -10dB sensitivity (which will reduce the voltage required to produce full power) and repeat

if you don't have a multimeter then you need to have the speaker connected, ear plugs in to avoid going deaf and then adjust the trim til the -3dBFS sine wave doesn't activate the clip lights on your monitors.

if you are using these in a surround setup so you have speakers at different distances then you'll have to give up some headroom somewhere, i.e. either by reducing the level to the nearer speakers thus not being able to drive them to full power or increasing the level to the more distant speakers and not being able to raise the MV as far (same difference in the end).
Thank you SO MUCH for taking all the voltage techno-babble and translating it in to "guy who want to listen to his monitors and not have them sound like ****".

I have a multi-meter. I can follow explicit instructions.

I am hopeful...
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post #11244 of 12239 Old 08-27-2014, 03:53 PM
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So, HD, does this mean we are good now? I have my REW kit set up and have run through the procedure I posted yesterday, and AFAICT the procedure is working fine. Your speaker levels look reasonable, and the RTA graph looks reasonable at 60Hz. Are there any other outstanding questions or issues?

BTW, setting the speakers to "Large", or powering off the sub, results in the same thing. I have four subs, so powering them off and on is not as easy as a couple of mouse clicks to set the speakers to large.
Besides being no closer to an answer you mean? The RTA method had me arrive at the same levels as suggested by my AVR. The REW test tone method wants me to lower the sub by about 5dB.

If the RTA method is bulletproof then great, I guess we're done. I just don't understand why both test tone CDs (two sets of pink noise) and REW both want my sub lower than the AVR and the RTA method...

It shouldn't work that way AFAIK, but in my system it does. I remain confused.
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post #11245 of 12239 Old 08-27-2014, 03:59 PM
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There is relative sound level, and then there is absolute sound level. Unfortunately, absolute sound level depends on the accuracy of our measuring devices. I have three such measuring devices. The first is a UMIK-1 USB mic with the CSL custom calibration file, loaded with a sensitivity parameter associated with my mic's serial number (downloaded from the MiniDSP web site). The second is a Radio Shack analog SPL. And the third is an iPhone app called AudioTools (maybe the same one HD is using?).

When playing a Speaker Cal Pink Noise signal, and with the left speaker's trim set so that the UMIK-1 is reading 75dB at the MLP, I took a reading with the two external SPL meters. The RS SPL measures ~78dB (can't read fractions of a dB on an analog scale that jumps around), and the AudioTools SPL measures 78.4dB.

So, what does this mean? I think the sensitivity parameter for the UMIK-1 is probably off be a few dB's, especially since both external SPL's measure 78dB. Is this the end of the world? No. Because when we set speaker levels, the important thing is that the relative levels across all speakers is as close as possible. So what if I am actually leveling the trims to 73dB instead of 75dB? This isn't a professional recording studio, so if I think the system output is a bit low, I'm going to increase the master volume.
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post #11246 of 12239 Old 08-27-2014, 04:04 PM
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Originally Posted by HDgaming42 View Post
Besides being no closer to an answer you mean? The RTA method had me arrive at the same levels as suggested by my AVR. The REW test tone method wants me to lower the sub by about 5dB.

If the RTA method is bulletproof then great, I guess we're done. I just don't understand why both test tone CDs (two sets of pink noise) and REW both want my sub lower than the AVR and the RTA method...

It shouldn't work that way AFAIK, but in my system it does. I remain confused.
I ran the same test, and did not have these results. For clarity, I used the Speaker Cal pink noise tone for the mains, and the Sub Cal test tone for the subs. The trim level for the sub channel that resulted in 75dB at the MLP was the same, whether I used the AVR test tones, the REW signal generator, or Markus' RTA approach.

I guess there is an anomaly somewhere in your setup.
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post #11247 of 12239 Old 08-27-2014, 04:23 PM
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I just created a new thread for the file size data discrepancy issue.

http://www.hometheatershack.com/foru...tml#post892377
Thanks, Jim. I got too tied up to create one myself. Better from you anyway.
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post #11248 of 12239 Old 08-27-2014, 04:30 PM
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Thanks, Jim. I got too tied up to create one myself. Better from you anyway.
JohnPM has responded and asked for the mdat. We should get an answer pretty soon.

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post #11249 of 12239 Old 08-27-2014, 04:43 PM
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Originally Posted by AustinJerry View Post
I guess there is an anomaly somewhere in your setup.
But where does it lie?

The only thing that agrees with my AVR is this RTA method, which makes no sense as it is using the same tone generator in REW that doesn't agree with my AVR...

Last edited by HDgaming42; 08-27-2014 at 04:51 PM.
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post #11250 of 12239 Old 08-27-2014, 04:51 PM
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Originally Posted by HDgaming42 View Post
But where does it lie?
Sorry, let us know when you find out. Or better yet, run Audyssey and accept whatever it creates as your speaker trims, and then sit back and enjoy.
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