Sanctuary Sweep

Thread Starter
Joined
Mar 24, 2019
Messages
28
John, I used the SPL to get the proper RT60, Waterfalls, and Spectrographs.
Attached, please find my results.
I believe the Waterfalls and Spectrographs clearly show problems in to < 200 Hz range.

Am I right?

Thanks,

Lee Terwilliger
 
Thread Starter
Joined
Mar 24, 2019
Messages
28
John, I used the SPL to get the proper RT60, Waterfalls, and Spectrographs.
Attached, please find my results.
I believe the Waterfalls and Spectrographs clearly show problems in to < 200 Hz range.

Am I right?

Thanks,

Lee Terwilliger

John, when I attached a file, the loading goes to 100%; then, the file title is grayed out with a line through it.
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
2,284
The file may be too large Lee, what size is it? I think the limit is 10 MB. If the file has many measurements in it you could save individual measurements into their own mdat files, or you could try to zip the file and attach the zip instead.
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
2,284
There are some big resonances below 100 Hz, also pretty high distortion levels. You are measuring a large space so you should use a longer right hand window, 1500 or 2000 ms, and don't use a frequency dependent window - it will obscure the resonances. I'll look at the measurements in more detail tomorrow.
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
2,284
Here are the overlaid SPL traces, showing the low frequency resonances. The SPL figures seem very high, does the UMM-6 cal file have sensitivity data? May want to go through SPL calibration if it doesn't. If those are actual levels they are much, much higher than needed for measurement.

25645


Here is an example of the distortion I mentioned, pretty high everywhere, perhaps because the levels are high:

25646
 
Thread Starter
Joined
Mar 24, 2019
Messages
28
How did you get the Right hand window and s
Also, the UMM-6 Mic has a Sensitivity at 1 KHz (+30 dB IPGA): -19 dBFS/Pa
(Sensitivity is adjustable using Windows volume control)
Eat
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
2,284
Regarding the sensitivity, I was referring to an entry in the cal file for the mic of the form "Sens Factor =-15.223dB, SERNO: 7000139". It is usually the first line in the cal file.

The RH IR window is set in the IR Windows dialog, using the button in the toolbar.
irwindowsbtn.jpg
 
Thread Starter
Joined
Mar 24, 2019
Messages
28
The cal file (.txt) has the following first line.
“Send Factor =-19.009dB, SERNO: 1780552”

Does that Help?

At What level should I set the Cal signal?
 

John Mulcahy

REW Author
Joined
Apr 3, 2017
Messages
2,284
I think you ran the sweep at -3 dBFS, try running it at -20 dBFS. The sweep should not be uncomfortably loud at the mic position.
 

Rich Elliott

New Member
Joined
Oct 13, 2019
Messages
1
Looking at the curves is it possible the gain structure or your system is upside down? Meaning the amps are wide open and the board is throttled back? Might consider pumping a reference level thru the board and setting the gain structure then setting amp gain with an spl meter for starters. the levels you show are uncomfortable and over stimulating the room and will certainly cause distortion.
 
Thread Starter
Joined
Mar 24, 2019
Messages
28
The Sanctuary Floor is 48 ft 8 3/8 in wide (N to S direction); 47 ft 8 1/2 in long (E to W direction
 
Thread Starter
Joined
Mar 24, 2019
Messages
28
John:
The Sanctuary Floor is 48 ft 8 3/8 in wide (N to S direction); 47 ft 8 1/2 in long (E to W direction); N and S walls are 9 ft 10 1/2 in high and 47 ft 8 1/2 in length. E and W walls are 48 ft 8 3/8 in long and a ceiling peak at 15 ft 11 in. The ceiling slope is 3/12 slope. There are two storage rooms; one at each of the E end of the N and S walls - total of 694 cuft, Stage and steps on E end of the Sanctuary are 494 cuft. Sanctuary Volume (without the storage rooms and the stage, steps) is 28,773 cuft. N and S walls have a total of 78 sqft of plate glass windows; W wall has a total of 119 sqft of plate glass; E wall has 48 sqft of metal double doors, 18 sqft of hollow wood door and 32 sqft of opening to kitchen.
Hope this Helps,
Lee
 
Top Bottom