Home Theater Forum and Systems banner

1 - 5 of 5 Posts

·
Registered
Joined
·
166 Posts
Discussion Starter #1
Can anyone tell me the correct orientation of the microphone and the RS 33-4050 meter for testing purposes? I originally had the mic vertical and was using the RS horizontally and was told that this is incorrect. So, can someone tell me the correct setup?

Thanks,

Bob
 

·
Registered
Joined
·
678 Posts
Since I helped provoke this discussion, I should probably chime in and elaborate the comments I made to Bob in an Audyssey thread.

One question Bob had was with the response of his speakers at the high end, above 10kHz. My observation was that the generic ECM8000 calibration file seems similar to the response that Herb showed in one of his detailed reports on an ECM8000 for the 0° orientation. It shows a response above 0dB at the high end, when oriented at 0°, where the response of the ECM8000 falls off above 10kHz, down to -5dB, when oriented at 90°. So, when measuring with a near vertical orientation using the generic calibration file, one is going to measure a more rapid fall-off above 10kHz than is real.

Obviously, a vertical orientation will capture more reflected energy, especially from behind the listening position. It will guarantee an omnidirectional response which might be useful when evaluating room treatments. But even here, if I read the polar chart in Herb's sample report correctly, the ECM8000 shows significant directivity above 1kHz, at 5kHz, up to +5dB at 10kHz. At lower frequencies, the effect does not matter. As Wayne wrote above, when looking at equalization at low frequencies, the orientation does not matter.

Bill
 

·
Super Moderator
Joined
·
9,252 Posts

Thanks for clarifying, Bill. :T

Don’t know if this came through on the thread(s) you were referring to, but our generic ECM8000 file is a 0° incident file and absolutely should not be used for measurements taken with the mic at 90°. If 90° measurement is desired, then a 90° calibration file is required. These posts document the “whys” and “wherefores” of correct mic orientation for horizontal or vertical measurements.

Link
Link


Regards,
Wayne
 

·
Registered
Joined
·
166 Posts
Discussion Starter #5
Since I helped provoke this discussion, I should probably chime in and elaborate the comments I made to Bob in an Audyssey thread.

One question Bob had was with the response of his speakers at the high end, above 10kHz. My observation was that the generic ECM8000 calibration file seems similar to the response that Herb showed in one of his detailed reports on an ECM8000 for the 0° orientation. It shows a response above 0dB at the high end, when oriented at 0°, where the response of the ECM8000 falls off above 10kHz, down to -5dB, when oriented at 90°. So, when measuring with a near vertical orientation using the generic calibration file, one is going to measure a more rapid fall-off above 10kHz than is real.

Obviously, a vertical orientation will capture more reflected energy, especially from behind the listening position. It will guarantee an omnidirectional response which might be useful when evaluating room treatments. But even here, if I read the polar chart in Herb's sample report correctly, the ECM8000 shows significant directivity above 1kHz, at 5kHz, up to +5dB at 10kHz. At lower frequencies, the effect does not matter. As Wayne wrote above, when looking at equalization at low frequencies, the orientation does not matter.

Bill
Hi Bill & Wayne. Thanks for the responses. I've decided to redo my setup with REW. I wanted to make sure I was starting off correctly before I went thru all of this and had to change something later to get a better measurement and have to redo much of my work. I also did a little research on my speakers (Atlantic Tech 4200e) and decided to play around with the HF Energy and Boundary Compensation adj. on the back of the speakers. Using REW, it would seem that I get the most flat response around 75db using the "Damped" setting and not the Reverberated setting I thought that I should use because of the tile floors I have thru-out my house. I was able to see the differences that each switch made to the speakers' response with REW...

Bob
 
1 - 5 of 5 Posts
Top