Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How To Interpret Graphs - Page 13 - AVS Forum
Forum Jump: 
 9Likes
Reply
 
Thread Tools
post #361 of 10741 Old 01-15-2013, 01:00 PM
AVS Special Member
 
mogorf's Avatar
 
Join Date: May 2009
Location: Budapest, Hungary
Posts: 4,214
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Liked: 96
Quote:
Originally Posted by AustinJerry View Post

It is normally considered a better practice to aim the microphone at the ceiling because it takes into account the contributions of the room.  Pointing the mic directly at the speaker is better if you are interested in analyzing a specific speaker's response.  Also note that if you want to measure the combined output of left+right+subs, it is impossible to aim the mic at multiple sound sources at the same time, so aiming at the ceiling produces the better measurement.  After all, you don't aim the Audyssey mic directly at the speaker, do you?

Jerry et all,

Pointing the mic to different directions: well noted and makes perfect sense! On the otherhand if we look at the UMM-6 calibration graph of Cross-Spectrum we can see that up to 1 kHz there is practically no difference between 0, 45 and 90 degrees, while above 1 kHz things start to change a bit:



Cross-Spectrum page here.

My Q with the UMIK-1 (or any other commercially available condenser type test mic) is: do we really need to be surgically precise with the calibration files for different directions and always choose the appropriate file, or no need to sweat on it too much due to minute differences that only appear at the top of the HF side?

Note: the above graph has been taken with 1/3rd octave smoothing, while no smoothing may reveal something more below 1 kHz. wink.gif Hopefully not much.

Another note: once we have a known calibration file, say for 0 degrees, we can take another measurement by pointing the mic to the ceiling, read the differences from the graph and create another cal file, save it as .txt and load it into REW. Seed for thought! smile.gif
mogorf is online now  
Sponsored Links
Advertisement
 
post #362 of 10741 Old 01-15-2013, 01:32 PM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632
Feri, you can do whatever you want to. However, I prefer the incremental accuracy of the individually-calibrated mic. Recall that the Mini-DSP uses a generic calibration file, while Cross-Spectrum labs provides the extra service of calibrating each microphone.

Would I want to manually adjust a measurement file to compensate for the differences between the 0 and 90 degree response curves? No, I would not.

Why are you being so persistent in defending the Mini-DSP mic over the UMM-6 mic? I don't think it makes a hughe difference, but please let the rest of us choose what we want to.
AustinJerry is online now  
post #363 of 10741 Old 01-15-2013, 01:59 PM
AVS Special Member
 
mogorf's Avatar
 
Join Date: May 2009
Location: Budapest, Hungary
Posts: 4,214
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Liked: 96
Quote:
Originally Posted by AustinJerry View Post

Feri, you can do whatever you want to. However, I prefer the incremental accuracy of the individually-calibrated mic. Recall that the Mini-DSP uses a generic calibration file, while Cross-Spectrum labs provides the extra service of calibrating each microphone.

Would I want to manually adjust a measurement file to compensate for the differences between the 0 and 90 degree response curves? No, I would not.

Why are you being so persistent in defending the Mini-DSP mic over the UMM-6 mic? I don't think it makes a hughe difference, but please let the rest of us choose what we want to.

Jerry, what I'd like to see clearly is whether we really need to be dead on with mic specs or there is a certain range of tolerance we can all live with without seriously affecting the end results. Of course the slogan shall remain: "each his own". Agree? smile.gif
mogorf is online now  
post #364 of 10741 Old 01-15-2013, 04:04 PM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by sdrucker View Post

Quote:
Originally Posted by kbarnes701 View Post

IDK what J does, but did I not read he is setting up his own acoustics company?  J?

This is what I think I will love about REW once it is working here. I can make one measurement file, with all the measurements in it that I need for that session and then go and sit and analyse those measurements every whichway, at my leisure. If I want different smoothing, I apply it... if I want a waterfall, I generate it, if I want an ETC, I create it... And best of all, I can send my data file to the experts and THEY can analyse it for me and tell me where I am going wrong or what I need to do next (if I get stuck). This is way, way ahead of OM...


By the time you're done, you're going to wind up creating Powerpoint presentation with all the charts you'll have from a given configuration smile.gif

 

This is the problem with Windows - so many potential combinations of OS versions, hardware, firmware, drivers, etc etc etc. But often it's fairly obvious - if a screenie says XXXX Soundcard and you have YYYY soundcard, it's still a soundcard.... ;)

kbarnes701 is online now  
post #365 of 10741 Old 01-15-2013, 04:07 PM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by AustinJerry View Post


Why are you being so persistent in defending the Mini-DSP mic over the UMM-6 mic? 

 

Would this be because it's the one he's bought?  :) ;)

kbarnes701 is online now  
post #366 of 10741 Old 01-15-2013, 04:16 PM
AVS Special Member
 
mogorf's Avatar
 
Join Date: May 2009
Location: Budapest, Hungary
Posts: 4,214
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Liked: 96
Quote:
Originally Posted by kbarnes701 View Post

Would this be because it's the one he's bought?  smile.gifwink.gif

Not bought, but will buy! BTW, why buy a non-PNP mic when a PNP mic is or will be available for "him" soon. smile.gif
mogorf is online now  
post #367 of 10741 Old 01-15-2013, 04:58 PM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632
Quote:
Originally Posted by mogorf View Post


Jerry, what I'd like to see clearly is whether we really need to be dead on with mic specs or there is a certain range of tolerance we can all live with without seriously affecting the end results. Of course the slogan shall remain: "each his own". Agree? smile.gif

 

My friend Feri,

 

What is a discussion without facts and data?  To support my case, I have devised the following test:

 

- Pulled out and set up the "legacy" REW kit, which includes an individually-calibrated EMM-6 microphone with both zero and 90-degree calibration files.

- Configured my left speaker as a full-range speaker, and turned Audyssey and subs off (i.e. isolating the left speaker)

- Placed the mic at the MLP

- Ran the following tests:

 

1.  Full sweep with mic pointed at 90 degrees, with no calibration file

2.  Full sweep with mic pointed at 90 degrees, with 90-degree calibration file

3.  Full sweep with mic pointed at 90 degrees, with 0-degree calibration file

4.  Full sweep with mic pointed at 0 degrees (i.e. at the left speaker), with 0-degree calibration file

5.  Tests 2 and 4 repeated, with Audyssey on

 

Here are the measurements.  First, the three measurement taken with the mic pointing upwards at 90 degrees.  Below 600Hz, there is not much difference.  Above 600Hz, the curves begin to diverge, with a visible difference above 10kHz.

 

 

Second, here are two measurements, the red one with mic at 90 degrees using the 90-degree cal file, and the black one with the mic pointing directly at the speaker, with the 0-degree calibration file.  This graph shows significantly different curves above 400Hz.

 

 

Third, here is the same graph as the second one, but with Audyssey turned on.  Again, significant differences, but seen over the entire frequency range.

 

 

This experiment leads me to the following conclusions:

 

- First, with the microphone pointed at the ceiling, calibration files do make a difference, but the difference is subtle.

- Second, there is a significant difference in the measurement curves with the mic pointed toward the ceiling versus pointing the mic directly at the speaker.

 

So, one might ask, which of the two microphone orientations produces the more correct measurement upon which we should make decisions involving moving speakers, adding treatments, etc.?  If we choose the wrong one, our corrections may be flawed.

 

The Mini-DSP, as I understand it, comes only with the zero-degree calibration file.  So, with this mic, you can chose to point it directly at the speaker using the zero-degree calibration file, or point the mic at the ceiling zero-degree calibration file.  IMO, either is a compromise.

 

Based on this data, Feri, which mic orientation would you choose, now that it has been demonstrated that it makes a big difference?

AustinJerry is online now  
post #368 of 10741 Old 01-15-2013, 05:32 PM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632

FYI, in case you haven't experienced a "legacy" REW setup, here it is:

 

Rob Greer likes this.
AustinJerry is online now  
post #369 of 10741 Old 01-15-2013, 07:10 PM
Senior Member
 
asarose247's Avatar
 
Join Date: Mar 2010
Location: SoCal
Posts: 301
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 16 Post(s)
Liked: 32
follow up to post 338
when i select java in the preferences, obviously ASIO etc isnt selected BUT ta-da the HDMI output and the External mike are there!
and they "work "if i just run a measurent.
how much more backwards could i do this to get it right.

and the sound card configures to test 7.1 speakers

THE BIG ROOM:
Mitsy DLP 73837
Xbox
PS3 slim
Panny BD 220
Yamaha 775WA and Emotiva UPA7 for 9.2
Klipsch F3 FL/R, G-28 C, RS3C, FH's , RS3II SL/R, SLX SRL/R
2 30" BF THTLP'S with BASH 300 behind MLP
LG Media Player access to 3T drives

Da Cave ((9''8" x 11')
Panny 55" S1 , BD 220
Onkyo 160 7.1
Klips...
asarose247 is offline  
post #370 of 10741 Old 01-15-2013, 09:12 PM
AVS Special Member
 
djbluemax1's Avatar
 
Join Date: Oct 2004
Location: MI
Posts: 2,242
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 262
BTW, just thought I'd mention for all the folks having REW setup issues, I just ran into an HDMI output issue that took 20+ minutes to solve and the solution turned out to be stupidly simple (and annoyingly dumb).

Because there are so many different PC and Windows configurations possible, it's difficult to have one set of settings. In my case, my laptop's HDMI port does not natively output audio. I have to toggle that ON, but in this instance, toggling it on didn't work. It took 20+minutes to discover that I had to shut down and reset for the change to take effect. How annoying.


Max
djbluemax1 is offline  
post #371 of 10741 Old 01-16-2013, 03:11 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by mogorf View Post

Quote:
Originally Posted by kbarnes701 View Post

Would this be because it's the one he's bought?  smile.gifwink.gif

Not bought, but will buy! BTW, why buy a non-PNP mic when a PNP mic is or will be available for "him" soon. smile.gif

 

Sorry Feri - I thought you said you had ordered it already. If not, I would urge you to buy the calibrated UMM-6 which is a similar price and comes with 3 calibration files for 0, 45 and 90 degrees. The issue of it being PnP is a non-issue for someone with your technical expertise.

kbarnes701 is online now  
post #372 of 10741 Old 01-16-2013, 03:15 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by AustinJerry View Post

 

Based on this data, Feri, which mic orientation would you choose, now that it has been demonstrated that it makes a big difference?

 

Good job there AJ.  Personally, I can't see the point in buying a mic that is effectively UNcalibrated for its most common use (for us) which is in the 90 degree position pointing up to the ceiling. Not when there is a similarly priced mic available that is individually calibrated three ways. Yes, there is a little more to do (initially) with the UMM-6 but it has to be done once only and that is it. And with your excellent Guide to hand, it is an easy and straightforward process that anyone in this thread can master. Even me ;)

kbarnes701 is online now  
post #373 of 10741 Old 01-16-2013, 03:32 AM
AVS Special Member
 
JChin's Avatar
 
Join Date: Oct 2008
Location: Mesquite Tx
Posts: 8,423
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked: 122
Keith, curious whats the difference between getting it at CSL and Parts Express (see product details)?
JChin is offline  
post #374 of 10741 Old 01-16-2013, 03:36 AM
AVS Special Member
 
JChin's Avatar
 
Join Date: Oct 2008
Location: Mesquite Tx
Posts: 8,423
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked: 122
Quote:
Originally Posted by AustinJerry View Post

No, I am afraid my laptop hardware only supports 2 channels, regardless of the attempts I have made.  As I stated previously, being able to measure two channels provides the functionality one needs with REW.  You can measure left, right, center (as a combined left+right) and the subwoofers (through redirected bass from the main speakers).  I see no significant additional benefit from being able to measure surrounds or surround backs separately.  Of course, I could just be rationalizing my hardware deficiency...   wink.gif

Well that sucks. Wonder how hard it is to change out a sound card on a laptop?
JChin is offline  
post #375 of 10741 Old 01-16-2013, 04:27 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by JChin View Post

Keith, curious whats the difference between getting it at CSL and Parts Express (see product details)?

 

CSL individually calibrate each mic and issue a calibration file for 0, 45 and 90 degrees.

kbarnes701 is online now  
post #376 of 10741 Old 01-16-2013, 06:28 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632
Quote:
Originally Posted by JChin View Post

Well that sucks. Wonder how hard it is to change out a sound card on a laptop?

As I mentioned, I see no particular disadvantage of having only two channels. I have been using REW for several years with an external sound card which also has only two channels, and that never inhibited taking meaningful measurements. Why do you think this is an issue? There is no physical "sound card" in a laptop--it is a chip embedded in the laptop's motherboard.
AustinJerry is online now  
post #377 of 10741 Old 01-16-2013, 07:07 AM
Advanced Member
 
IgorZep's Avatar
 
Join Date: Sep 2012
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 61
Quote:
Originally Posted by AustinJerry View Post

Second, here are two measurements, the red one with mic at 90 degrees using the 90-degree cal file, and the black one with the mic pointing directly at the speaker, with the 0-degree calibration file.  This graph shows significantly different curves above 400Hz.




Third, here is the same graph as the second one, but with Audyssey turned on.  Again, significant differences, but seen over the entire frequency range.




This experiment leads me to the following conclusions:

- First, with the microphone pointed at the ceiling, calibration files do make a difference, but the difference is subtle.
- Second, there is a significant difference in the measurement curves with the mic pointed toward the ceiling versus pointing the mic directly at the speaker.

When I was experimenting with my mic angle I wasn't getting as much of a difference as you did on those graphs on the mid frequencies. This makes me worry that you get that difference because of some other reason than the mic angle. There might be the height/distance difference if you leave the center of the mic in the same place (the capsule placement is what matters). Also dip between 10-20kHz might suggest that you measure L+R on those graphs and then interference might also make great difference with minimal mic displacement.

Under 4kHz there is really a very minor difference in mic sensitivity on the direction, but with higher frequencies it is much less sensitive for sound coming from 90 degree, so when measuring at 0 degree we measuring direct sound mostly on those frequencies, but when pointing it to the ceiling reflections have much more weight over the direct sound than when measured at 0 degrees, and so is the difference in measurements in real rooms even when proper calibration files applied.
IgorZep is offline  
post #378 of 10741 Old 01-16-2013, 07:07 AM
Senior Member
 
cdnbum88's Avatar
 
Join Date: Apr 2009
Location: St. Louis
Posts: 394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by kbarnes701 View Post

CSL individually calibrate each mic and issue a calibration file for 0, 45 and 90 degrees.

I thought Jason noted the DSP mic could also be sent to get calibrated by someone? Could they have it calibrated for all 3 options? Again, I thought in general the pointing to the ceiling is what we wanted like Audyssey, so the DSP would be fine would it not? It comes with the 90 degree file.

cdnbum88 is offline  
post #379 of 10741 Old 01-16-2013, 07:16 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632
Quote:
Originally Posted by cdnbum88 View Post

I thought Jason noted the DSP mic could also be sent to get calibrated by someone? Could they have it calibrated for all 3 options? Again, I thought in general the pointing to the ceiling is what we wanted like Audyssey, so the DSP would be fine would it not? It comes with the 90 degree file.

I believe you are correct--the Mini-DSP mic could be sent to Cross-Labs for calibration, but this involves an additional expense and delay. And, IIRC, the Mini-DSP comes with a zero-degree calibration file, which is why we are having this discussion in the first place.
AustinJerry is online now  
post #380 of 10741 Old 01-16-2013, 07:23 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632
Quote:
Originally Posted by IgorZep View Post

When I was experimenting with my mic angle I wasn't getting as much of a difference as you did on those graphs on the mid frequencies. This makes me worry that you get that difference because of some other reason than the mic angle. There might be the height/distance difference if you leave the center of the mic in the same place (the capsule placement is what matters). Also dip between 10-20kHz might suggest that you measure L+R on those graphs and then interference might also make great difference with minimal mic displacement.

Under 4kHz there is really a very minor difference in mic sensitivity on the direction, but with higher frequencies it is much less sensitive for sound coming from 90 degree, so when measuring at 0 degree we measuring direct sound mostly on those frequencies, but when pointing it to the ceiling reflections have much more weight over the direct sound than when measured at 0 degrees, and so is the difference in measurements in real rooms even when proper calibration files applied.

Igor, when I changed the orientation of my mic, I re-measured to make sure the tip of the mic was still at ear-height and as close to the same spot as when it was oriented vertically. It's certainly possible that there could have been a slight variation, perhaps an inch or so, which could have contributed to some of the variance.

If you re-read my original post, the measurements were taken with only one speaker, not left+right. I still think the tests demonstrate that the best approach to producing accurate and meaningful REW measurements is to orient the mic towards the ceiling, and to use a calibration file that was specifically created for the 90-degree orientation.
AustinJerry is online now  
post #381 of 10741 Old 01-16-2013, 07:43 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by AustinJerry View Post

Quote:
Originally Posted by JChin View Post

Well that sucks. Wonder how hard it is to change out a sound card on a laptop?

As I mentioned, I see no particular disadvantage of having only two channels. I have been using REW for several years with an external sound card which also has only two channels, and that never inhibited taking meaningful measurements. Why do you think this is an issue? There is no physical "sound card" in a laptop--it is a chip embedded in the laptop's motherboard.

 

I agree with you Jerry FWIW. It is nice to be able to isolate all 7 channels in a 7.1 system but I can't see a lot of value in measuring the surrounds independently. I am open to persuasion otherwise, but currently I would be happy with measuring just the mains and the subs. This is what I have done with my OM and it seems to have yielded good results so far.

kbarnes701 is online now  
post #382 of 10741 Old 01-16-2013, 07:47 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by cdnbum88 View Post

Quote:
Originally Posted by kbarnes701 View Post

CSL individually calibrate each mic and issue a calibration file for 0, 45 and 90 degrees.

I thought Jason noted the DSP mic could also be sent to get calibrated by someone? Could they have it calibrated for all 3 options? Again, I thought in general the pointing to the ceiling is what we wanted like Audyssey, so the DSP would be fine would it not? It comes with the 90 degree file.

 

You can have the mic calibrated individually but I have no idea what that would cost. Seems pointless to me when you can get an already individually calibrated mic for the same sort of money. The mic that Feri and Jerry and I were discussing is only calibrated for 0 degrees AIUI, which means when it is used normally (pointed to the ceiling) it will have to be used uncalibrated. How much difference that makes is currently under discussion between Jerry and Igor. I take Igor's point that the room effects may well have more importance than minor calibration differences, but it still seems to me that as it is just as easy to use a fully calibrated mic, then I might as well.

kbarnes701 is online now  
post #383 of 10741 Old 01-16-2013, 07:53 AM
AVS Special Member
 
mogorf's Avatar
 
Join Date: May 2009
Location: Budapest, Hungary
Posts: 4,214
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 67 Post(s)
Liked: 96
Quote:
Originally Posted by kbarnes701 View Post

You can have the mic calibrated individually but I have no idea what that would cost. Seems pointless to me when you can get an already individually calibrated mic for the same sort of money. The mic that Feri and Jerry and I were discussing is only calibrated for 0 degrees AIUI, which means when it is used normally (pointed to the ceiling) it will have to be used uncalibrated. How much difference that makes is currently under discussion between Jerry and Igor. I take Igor's point that the room effects may well have more importance than minor calibration differences, but it still seems to me that as it is just as easy to use a fully calibrated mic, then I might as well.

Gyus, my point is that once you have at least one known calibration file (like 0 degree for the UMIK-1) for your mic then it's possible to generate another calibration file (like 90 degrees) from it and load it into REW. I'll come back later this evening to expand on my (brave) idea with a lot of reasonings. Stay tuned, please! smile.gif
mogorf is online now  
post #384 of 10741 Old 01-16-2013, 08:12 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by mogorf View Post

Quote:
Originally Posted by kbarnes701 View Post

You can have the mic calibrated individually but I have no idea what that would cost. Seems pointless to me when you can get an already individually calibrated mic for the same sort of money. The mic that Feri and Jerry and I were discussing is only calibrated for 0 degrees AIUI, which means when it is used normally (pointed to the ceiling) it will have to be used uncalibrated. How much difference that makes is currently under discussion between Jerry and Igor. I take Igor's point that the room effects may well have more importance than minor calibration differences, but it still seems to me that as it is just as easy to use a fully calibrated mic, then I might as well.

Gyus, my point is that once you have at least one known calibration file (like 0 degree for the UMIK-1) for your mic then it's possible to generate another calibration file (like 90 degrees) from it and load it into REW. I'll come back later this evening to expand on my (brave) idea with a lot of reasonings. Stay tuned, please! smile.gif

 

I would be interested in hearing you on this, Feri. I thought the idea of calibrating a mic was to calibrate it against a known reference instrument and to create a correction file for it where it is shown to deviate from the FR of the reference instrument. I can't quite see how you can calibrate the mic for vertical orientation unless you have a known reference mic to compare it with. But I am all ears...

 

But the real question is, is it all worth it?  The properly calibrated mic from CSL is more or less the same price as the partially calibrated UMIK-1 - so why not just get the UMM-6 from CSL and be done with it? 

 

The very minor benefit of the UMIK-1 being PnP is irrelevant IMO - anyone who can master the rest of REW will surely be able to perform the one additional step required when using the UMM-6.

kbarnes701 is online now  
post #385 of 10741 Old 01-16-2013, 09:48 AM
Senior Member
 
cdnbum88's Avatar
 
Join Date: Apr 2009
Location: St. Louis
Posts: 394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by kbarnes701 View Post

I would be interested in hearing you on this, Feri. I thought the idea of calibrating a mic was to calibrate it against a known reference instrument and to create a correction file for it where it is shown to deviate from the FR of the reference instrument. I can't quite see how you can calibrate the mic for vertical orientation unless you have a known reference mic to compare it with. But I am all ears...

But the real question is, is it all worth it?  The properly calibrated mic from CSL is more or less the same price as the partially calibrated UMIK-1 - so why not just get the UMM-6 from CSL and be done with it? 

The very minor benefit of the UMIK-1 being PnP is irrelevant IMO - anyone who can master the rest of REW will surely be able to perform the one additional step required when using the UMM-6.

The reason I noted my question was that I already have the mini dsp one now. I hope I did not jump the gun, but I think the differences would be minor and again with WAF, not sure what options I will have anyway once I produce some graphs and you all say, David, you 'should' move your sub 3 inches to left smile.gif

cdnbum88 is offline  
post #386 of 10741 Old 01-16-2013, 10:29 AM
AVS Addicted Member
 
kbarnes701's Avatar
 
Join Date: Jan 2008
Location: Main Listening Positon
Posts: 16,274
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 332 Post(s)
Liked: 1156
Quote:
Originally Posted by cdnbum88 View Post

Quote:
Originally Posted by kbarnes701 View Post

I would be interested in hearing you on this, Feri. I thought the idea of calibrating a mic was to calibrate it against a known reference instrument and to create a correction file for it where it is shown to deviate from the FR of the reference instrument. I can't quite see how you can calibrate the mic for vertical orientation unless you have a known reference mic to compare it with. But I am all ears...

But the real question is, is it all worth it?  The properly calibrated mic from CSL is more or less the same price as the partially calibrated UMIK-1 - so why not just get the UMM-6 from CSL and be done with it? 

The very minor benefit of the UMIK-1 being PnP is irrelevant IMO - anyone who can master the rest of REW will surely be able to perform the one additional step required when using the UMM-6.

The reason I noted my question was that I already have the mini dsp one now. I hope I did not jump the gun, but I think the differences would be minor and again with WAF, not sure what options I will have anyway once I produce some graphs and you all say, David, you 'should' move your sub 3 inches to left smile.gif

 

..... and "David, you do realise you need 12 bass traps and half a dozen diffusors in that space, don't you?"  :)

kbarnes701 is online now  
post #387 of 10741 Old 01-16-2013, 11:05 AM
AVS Special Member
 
AustinJerry's Avatar
 
Join Date: Jan 2003
Location: Austin, Texas
Posts: 6,746
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 168 Post(s)
Liked: 632
Quote:
Originally Posted by cdnbum88 View Post


The reason I noted my question was that I already have the mini dsp one now. I hope I did not jump the gun, but I think the differences would be minor and again with WAF, not sure what options I will have anyway once I produce some graphs and you all say, David, you 'should' move your sub 3 inches to left smile.gif

 

David, I don't think it will make a huge difference for you.  IIWY, I would still point the mic at the ceiling, and I would use whatever calibration file that came with the mic. 

AustinJerry is online now  
post #388 of 10741 Old 01-16-2013, 11:58 AM
Senior Member
 
cdnbum88's Avatar
 
Join Date: Apr 2009
Location: St. Louis
Posts: 394
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Keith - Yes I wish I could add all that good stuff. Who knows maybe some day. I just need to get running the graphs to post for you guys to look at and offer up what things I may or may not be able to try.

AustinJerry - the plan was to point up, so I think I am good with that, as noted, I just need some quiet time without wife and kids to do some at least some single position runs for all the speakers.

cdnbum88 is offline  
post #389 of 10741 Old 01-16-2013, 01:24 PM
Advanced Member
 
IgorZep's Avatar
 
Join Date: Sep 2012
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 61
Quote:
Originally Posted by AustinJerry View Post

If you re-read my original post, the measurements were taken with only one speaker, not left+right. I still think the tests demonstrate that the best approach to producing accurate and meaningful REW measurements is to orient the mic towards the ceiling, and to use a calibration file that was specifically created for the 90-degree orientation.

I fully agree with you, just wanted to ensure as I've had different experience with variance of mid-frequency range. Although I have ECM8000, not EMM6. They should be quite similar, but still there might be some difference coming from that as well.
IgorZep is offline  
post #390 of 10741 Old 01-16-2013, 01:31 PM
Advanced Member
 
IgorZep's Avatar
 
Join Date: Sep 2012
Posts: 544
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Liked: 61
Quote:
Originally Posted by mogorf View Post

Gyus, my point is that once you have at least one known calibration file (like 0 degree for the UMIK-1) for your mic then it's possible to generate another calibration file (like 90 degrees) from it and load it into REW. I'll come back later this evening to expand on my (brave) idea with a lot of reasonings. Stay tuned, please! smile.gif

Yes, I believe it should be possible with quite a good precision. The most of the difference in 90 degree and 0 degree performance is from the shape of the mic, I believe, so if you apply the difference from one mic to another it should be pretty good already. Not as precise as a separate calibration, but order of magnitude better than just taking generic profile for the mic.
IgorZep is offline  
Reply Audio theory, Setup and Chat

Tags
Dayton , Dayton Audio , Room Equilizer Wizard Rew

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off