How to hold the mic?

[kaos]

So I'm on my 3rd year of continuosly calibrating my system (I always find something new) and was curious about speaker levels and the YPAO EQ optimzer.

When I setup my SPL for speaker levels I just hold it in front of me pointing up at an angle until all volumes are registered equal. Today, I thought, wouldn't it make sense to point the SPL mic in the directions of the tones instead of just pointing it up to catch the ambience? So I point the mic in the direction of each tone and calibrate it that way. Some levels end up being adjusted a few decibles. This was just an experiment to see how the difference would sound and to my suprise the overall sound was much more natural. I started off by playing the DTS edition of HEAT (Region 2 Japan DVD) and the atmostphere in downtown LA felt much more realistic. Then I threw in the DTS pod race from Episode 1 (THX Ultimate Demo DVD) and that too sounded much more involving. To finish it off I played the gunfight from Matrix Revolutions and I noticed a lot more debris flying around my head and it just sounded a lot more realistic and involving. So it seemed as though the surrounds were finally calibrated at the right levels to truly match the front volumes as opposed to calibrating them with the SPL meter pointing up at an angle. There was about a 2db jump in volume for the surrounds.

So then I thought, if the SPL adjustment made me more satisfied with my system why not do the same with the YPAO mic? So I did and I didn't notice a difference from pointing the mic at the given tones than from having it sit there on a stand pointing up. It sounded the same as before, atleast that's what I thought. What are the advantages and disadvantages of pointing the mics at the test tones instead of straight up?

What do you guys think?

 

[WmAx]

When I setup my SPL for speaker levels I just hold it in front of me pointing up at an angle until all volumes are registered equal.

You are not supposed to be near the microphone. It should be on a small profile boom stand, positioned at the listening position.Your body will affect measurements, throwing off the accuracy.

Today, I thought, wouldn't it make sense to point the SPL mic in the directions of the tones instead of just pointing it up to catch the ambience?

I don't know a thing about the particular microphone you are using, but a proper RTA measurement microphone is omnidirectional, even in the treble band, so pointing it upwards or straight ahead would have very little difference in the measurement results(at least up to 12-15kHz or so) for the front spekears. However, the rear structure may have some substantial difference at >12kHz, thus why it's a good idea to use such a mic in a upwards pointing position for surround sound calibration.

-Chris

 

[kaos]

The reason I'm in the listening position with the ypao mic is because that's where I'll be sitting during the movie. Shouldn't the ypao take in to account that there will be something (me) in the listening position during the movie, thus it should measure around me? If I were to measure without me in the room then once I sit down won't it affect the results? I'd be in the way, so shouldn't I be in the way while it's measuring, taking me in to account as being part of the room?

Also, I'm using the RadioShack Digital Sound Level Meter. In the manual, it says to point the mic at the source of the tone.

Thanks for the help, btw!

 

[WmAx]

The reason I'm in the listening position with the ypao mic is because that's where I'll be sitting during the movie. Shouldn't the ypao take in to account that there will be something (me) in the listening position during the movie, thus it should measure around me?

Only if the software was designed to accomodate this factor. Which it is probably not, since the standard is to measure with a mic and boom.

Also, I'm using the RadioShack Digital Sound Level Meter. In the manual, it says to point the mic at the source of the tone.

That is not a proper device for full range measurements. Also, due to the phyiscal size of the device, it will have directional properties at higher frequencies. It will be fine for white or pink noise SPL measurements or <6kHz sine wave SPL measurement; but be sure to use a correction chart for <100Hz range.

-Chris

 

[kaos]

What would be a good mic to use for volume calibration?

 

[WmAx]

What would be a good mic to use for volume calibration?

The RS SPL meter will be fine with white or pink noise. Just put it on a basic straight up stand or tripod and rotate it to point direclty at each speaker you are setting SPL.

-Chris

 

[kaos]

Will do. Thanks a lot for the help!