Compliments of GIK Acoustics. We would like to thank GIK Acoustics for preparing a very nice YouTube Tutorial on how to use REW. GIK tells us it is the first of several we can look forward to seeing. Thank you GIK!
Sonnie
Hi Sonnie, i agree thanks to GIK and yourself for posting this.
Hopefully there will be more tutorial videos, personally i would rather watch a video than read a book.
It would be great to watch tutorial videos, to what is best used for a certain application, and frequency range.
Keep it up
A good mic is certainly desirable for best effect. That said, even something as simple as the Radio Shack meter, USB external sound card, and the correction file for the RS meter will still get you a long way. When you're looking for relative change, we can still see that even with the inconsistencies in that sort of setup.
..... and there will be more videos.
Bryan
..... and there will be more videos.
Bryan
Re: REW YouTube Tutorial, loopback query
Thank you for the in-depth video! It definitely helped.
It's just one of those things, though--I am still not sure if I have set up my little 2-channel M-Audio Fast Track Audio Pro to successfully complete the soundcard calibration...
Was hoping you could help me kill the confusion about 1) what my soundcard and the line input/outputs should look like beforehand, and 2) how to set up the Preferences/Soundcard settings to successfully complete the calibration test in REW.
Channel 1 ('left') has a 1/4" jack looping back to the Channel 1 output. In effect, my left monitor speaker is now disconnected from the sound card, yes? I've run the 'Levels' test using Main Speaker to Check Level, and I've got my Channel 1 input level boosted to match the -12dB noise from the software, which is only coming out the right monitor speaker. Clicked ok finish.
Channel 2 ('right') has an XLR leading to my Beyerdynamic MM1 Electret, input level at 0, phantom power on.
Have also ticked the 'Use Loopback as a Timing Reference' box under 'Analysis'.
I'm pretty sure I'm supposed to set 'Input Channel' to Right and then hit Calibrate, but...I feel like I"m missing something! And the result back from the sine sweep test is always "You're about -34 dB short." Any help on this?
Much obliged if you could point me in the right direction elsewhere if not. Thank you much
Thank you for the in-depth video! It definitely helped.
It's just one of those things, though--I am still not sure if I have set up my little 2-channel M-Audio Fast Track Audio Pro to successfully complete the soundcard calibration...
Was hoping you could help me kill the confusion about 1) what my soundcard and the line input/outputs should look like beforehand, and 2) how to set up the Preferences/Soundcard settings to successfully complete the calibration test in REW.
Channel 1 ('left') has a 1/4" jack looping back to the Channel 1 output. In effect, my left monitor speaker is now disconnected from the sound card, yes? I've run the 'Levels' test using Main Speaker to Check Level, and I've got my Channel 1 input level boosted to match the -12dB noise from the software, which is only coming out the right monitor speaker. Clicked ok finish.
Channel 2 ('right') has an XLR leading to my Beyerdynamic MM1 Electret, input level at 0, phantom power on.
Have also ticked the 'Use Loopback as a Timing Reference' box under 'Analysis'.
I'm pretty sure I'm supposed to set 'Input Channel' to Right and then hit Calibrate, but...I feel like I"m missing something! And the result back from the sine sweep test is always "You're about -34 dB short." Any help on this?
Much obliged if you could point me in the right direction elsewhere if not. Thank you much
I'm not familiar with that. I spoke with Glenn and he had the same thought that I did - as long as it shows as a soundcard and is bi-directional, it should be fine.
Bryan
Bryan
A bi-directional sound card simply means that it's capable of playback and recording at the same time.
Bryan
Bryan
Among other things, REW can help you determine where to set the crossover frequencies for your PA system as well as equalize it. Hard to be more specific without more details on your system and/or intended application.
Regards,
Wayne
Accuracy of these systems can be dependent on outside dependencies such as hardware, product and subject familiarity and even weather/climate. I personally use a combination of REW for my main measurments and XTZ for validation if something does not look correct to me.
Thank you, thank you, thank you!
I used to use REW a few years ago. This video will bring me back up to speed in no time, (well, about 9 minutes and 34 seconds!)
I used to use REW a few years ago. This video will bring me back up to speed in no time, (well, about 9 minutes and 34 seconds!)
Great video! However, there is a significant error at about 3:25 when it says to perform the measurement with the mic in an upright position, but neglects to mention that this requires a special calibration file for 90-degree orientation. Traditionally horizontal orientation has been used for frequency response measurements in minimally-reverberant free-field environments like we find with the typical home theater. It should be mentioned the our generic calibration files for the Behringer ECM8000 and Dayton EMM-6 mics are 0-degree files for horizontal orientation. More reading on mic orientation in the links found in this post.
Regards,
Wayne
Hi Wayne
Here is a quote from the REW download link where they talk about mics and calibrations:
"For listening position measurements we recommend that the meter or mic be oriented vertically with a forward angle of about 10 - 20 degrees to capture a good mix of direct and reflected sound for 'room' measurements.
For near-field measurements we recommend a horizontal position to give the most accurate high frequency readings."
Since we're doing listening position testing, the vertical orientation is what is recommended.
Bryan
Here is a quote from the REW download link where they talk about mics and calibrations:
"For listening position measurements we recommend that the meter or mic be oriented vertically with a forward angle of about 10 - 20 degrees to capture a good mix of direct and reflected sound for 'room' measurements.
For near-field measurements we recommend a horizontal position to give the most accurate high frequency readings."
Since we're doing listening position testing, the vertical orientation is what is recommended.
Bryan
Hey Brian,
Unfortunately, the REW Downloads page – and the video - neglects to mention the need for a proper calibration file when taking measurements with the mic in an upright position.
It’s a well-known fact that the mic’s off-axis response is depressed in the upper frequencies compared to its on-axis response. For reference, see the graph below of measurements for a Dayton EMM-6 mic as performed by Herb Singleton of Cross Spectrum Labs. As you can see, when the mic is oriented 90-degrees of-axis from the signal source, its response at 20 kHz is a full 8 dB down.
Thus, room measurements taken with the mic upright, without the proper 90-degree calibration file, will show a droop in response above ~2 kHz that will not accurately reflect the speaker’s response or what the user actually hears. We've seen it happen here many times over the years, REW users perplexed about their poor measured response in the upper frequencies, only to find out that they weren't using the proper calibration file when they measured with the mic upright.
Dayton EMM-6 On and Off Axis Frequency Response
Courtesy of HiFi Zine
Regards, Wayne
Above 2k i'm not too worried about. What we're trying to really tame is primarily below say 400Hz where the response is pretty much identical. If a 90 degree file is required, then it's something we should have on the site.
Bryan
Bryan
Isn't the iso curve used by many professionnals supposed to decrease gently above 2K ?
This would mean that the given curve (as wayne highlighted) is near to what it should idealy be and poor measurements of the treebles doesn't mean that it simply doesn't exist or that you can't hear it.
A treeble uprising its power above 2k measured at 90 degrees would be dreadfull to hear and challenging to listen to more thant a few minutes.
After mesuring, when you start equalizing your room, feel free to push it up a bit just to have your own idea, it sometimes can make beautifull enhancements and sometimes can make everything sound really bad. It depends of the tweeter quality/softness/crisspiness. ;-)
Everything may sound good out of the ideal curve, just give it a try after you've reached it.
Ideally for me, I try to flattent the more I can to stick to the ideal curve and then I unleash it to different point from what I am hearing and what I wish to reach.
So reaching the ideal curve is simply where the real work begins for me.
This would mean that the given curve (as wayne highlighted) is near to what it should idealy be and poor measurements of the treebles doesn't mean that it simply doesn't exist or that you can't hear it.
A treeble uprising its power above 2k measured at 90 degrees would be dreadfull to hear and challenging to listen to more thant a few minutes.
After mesuring, when you start equalizing your room, feel free to push it up a bit just to have your own idea, it sometimes can make beautifull enhancements and sometimes can make everything sound really bad. It depends of the tweeter quality/softness/crisspiness. ;-)
Everything may sound good out of the ideal curve, just give it a try after you've reached it.
Ideally for me, I try to flattent the more I can to stick to the ideal curve and then I unleash it to different point from what I am hearing and what I wish to reach.
So reaching the ideal curve is simply where the real work begins for me.
I'm definitely going to check out this video, I'm curious as to how this all works and would like to try it out but not before understanding how to use it. From reading all the post above it sounds complicated.
pddufrene, I was right there with you.. I've been sitting on my uMIK for months now.. but, I've finally made moves to get started, got my DSP1124 today - my monoprice order of wires is coming in tomorrow.. so hopefully with some help from videos like these and the Shack/AVS forums I can get up & running in no time.. fingers x'd :gulp:
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