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Audioholics Room Correction Mic Placement Tutorial

Beershaun

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Audioholics has just posted a youtube video on Room Correction Microphone placement. I found it very informative and helpful for understanding where exactly and how to place my microphone for multiple measurements. It covers Audyssey, ARC Genesis, and Dirac.

 
Same. I like the tip on having a second mic holder in the center of the stand to bring my ARC G mic back to same center position for subwoofer phase integration. Also on the height being not below the back of the seat so the rear speakers have line of sight. I can go back and re-measure and go a bit higher than I thought for the highest mic positions.
 
There are a lot of things that raise an eyebrow for me. It is not clear to me that he knows the reason behind the recommendations he is making. If he had shown measurements of different ways and compared them, then that would be a lot more useful.
 
Didn’t watch the whole thing, even at 2x the value-for-time plummeted where I stopped watching - dude really doesn’t know that camera adapters for mic arms exist? I mean, that’s basic and they’re cheap, e.g.



Basically it’s a lot of time to say something kind of obvious: use a boom stand, make sure the mic is centered between L and R for (and aligned as expected for the other channels), and then sample some random points in the vicinity, varying all three dimensions. The only difference is RoomPerfect, where you sample the whole room instead of the area around where you sit.
 
There are a lot of things that raise an eyebrow for me. It is not clear to me that he knows the reason behind the recommendations he is making. If he had shown measurements of different ways and compared them, then that would be a lot more useful.
Agreed. Showing the difference in the output comparing different positions or number of points would be helpful to prove his recommendations or understand why.

I think there is some value in the basics here. Use a real mic stand. Make sure your mic always has clear line of sight to all speakers and is not so low it's blocked by the back of the couch. Putting a second mic holder in the middle of the stand so you can go back to the main listening position with some accuracy. Picking a main seat and not trying to split rows. Those basic tips are helpful for folks who are looking for clear instructions that the manufacturers don't do a good job giving.
 
I have been involved with "Home Theater " EQing since 1993.

First time I've seen such a tight 24" measurement window.
Started with RTA in five positions.
Then moved into THX specifications.
THX recommended some weighting for main listening position.
Warned against room boundaries and seating cushion proximity also.
Before computer usage for calibration.
 
Honestly it's pretty fine for those new to doing measurements who might be unsure exactly how to do the setup for the room calibration with just the directions that accompany the systems, which might be difficult to interpret.

I did notice that during the ARC demonstration he placed the mic stand so that it was between the speakers and the mic. I'm not sure if that would be an issue or not actually, but I always assumed you wanted to avoid that.
 
Honestly it's pretty fine for those new to doing measurements who might be unsure exactly how to do the setup for the room calibration with just the directions that accompany the systems, which might be difficult to interpret.

I did notice that during the ARC demonstration he placed the mic stand so that it was between the speakers and the mic. I'm not sure if that would be an issue or not actually, but I always assumed you wanted to avoid that.
Yes causes turbulence, sound wave breakup. Think of it as a plane's fuselage traveling through the air behind the fuselage will be breakup of the air (sound waves) caused by the airframe fuselage.
Also keep the Audisey Mike damped and clamped with set screw to avoid rattle, most cameras tripods have a rubber damper.
 
I am no expert on Dirac, not in a longshot.
But i have had it since day 1 when the first pc version (2014?) was released up to today.
So countless measurements taken all over the place.

My conclusion is to always measure a tight space, 5 or 6 points only.
~40cm from the first point.

If you measure the whole space as the graphic shows the frequancy response will be all over the place.
And Always verify with REW, there is always a risk the crossoverpoint will be screewed.

The main fault Imo is that you cant sweep with the speakers as small.
 
I am no expert on Dirac, not in a longshot.
But i have had it since day 1 when the first pc version (2014?) was released up to today.
So countless measurements taken all over the place.

My conclusion is to always measure a tight space, 5 or 6 points only.
~40cm from the first point.

If you measure the whole space as the graphic shows the frequancy response will be all over the place.
And Always verify with REW, there is always a risk the crossoverpoint will be screewed.

The main fault Imo is that you cant sweep with the speakers as small.
Agreed, but about the always verify....part, try telling that to many ARCG users lol, though I am happy to see that quite a few here on ASR seems to have listened, and have done their fair part posting their graphs. I think, and hope the next part of Audioholics ARCG, Audyssey and DL calibration related videos will include some REW graphs.
 
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Get one of these with your boom Mike stand.
For adapting microphones stands for camera's pivoting.

Gator Frameworks Camera Mount Mic Stand Adapter with Ball-and-Socket Head (GFW-MIC-CAMERA-MT) - $11​



 

Oak is hard wood, so better at dealing with acoustic build up and amplification, but only at certain frequencies.​

Maybe a metal Mike stand tube and one of these would be better for EQing.

GRIFITI Nootle Quick Release Pipe Clamp 1/4 20 Thread Camera & Nootle Mount for Tripod Music Microphone Pole​


 
I think, and hope the next part of Audioholics ARCG, Audyssey and DL calibration related viddeos will include some REW graphs.

I wouldn't expect that, because doing so would disprove the thesis - that there is some secret sauce to choosing sampling points, beyond basic best practices (use a stand, vary points in 3D, etc).

Also, then you can run into the problem that people wasting time and energy to take measurements that invite systemic error - obsessive focus on using "the same points." The confirmatory sample should actually a be spatial average of random points covering roughly the same volume.
 
And Always verify with REW, there is always a risk the crossover point will be screewed.

Indeed. The predicted frequency response in Dirac is never what I actually get, so when fine-tuning the crossover point I always run REW RTA with pink periodic noise to see which setting gives the smoothest frequency response.
 
I wouldn't expect that, because doing so would disprove the thesis - that there is some secret sauce to choosing sampling points, beyond basic best practices (use a stand, vary points in 3D, etc).

Also, then you can run into the problem that people wasting time and energy to take measurements that invite systemic error - obsessive focus on using "the same points." The confirmatory sample should actually a be spatial average of random points covering roughly the same volume.
Same volume?
What do you mean?

Interpreting to 20" circumference around initial point, as per presentation?
 
Don’t measure around your main seat and measure on top of the left speaker.
So it is just a different version of weighting, except as per video on the left hand side.
That was chosen location of primary listening position, left side front of room, very tight window of EQ.
 
The predicted frequency response in Dirac is never what I actually get, so when fine-tuning the crossover point I always run REW RTA with pink periodic noise to see which setting gives the smoothest frequency response.
Do you also do this at different volumes, e.g. 60dB(Z), 70dB(Z), 80dB(Z), 90dB(Z), ...?
 
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