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Thanks for the reply John. So based on your answer it sounds like either one (C or Z weighted) is fine and will give the same outcome once we go above the noise floor. currently the noise floor on a C-weighted reading is roughly 49-50dB. So when I set the tone generator to -12dbs and play pink noise, I should raise the volume up on the AVR until the SPL meter is reading 75dB, and that will be enough to properly measure the room/setup.
 

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Thanks for the reply John. So based on your answer it sounds like either one (C or Z weighted) is fine and will give the same outcome once we go above the noise floor. currently the noise floor on a C-weighted reading is roughly 49-50dB. So when I set the tone generator to -12dbs and play pink noise, I should raise the volume up on the AVR until the SPL meter is reading 75dB, and that will be enough to properly measure the room/setup.
Good questions in your post and a good reply from John, made me think for a bit as I have never bothered to set the weighting to Z didn't even know the UMIK1 was Z rated, I have always left the SPL meter set at C weighting. I have been doing quite a lot of system sweeps recently for various reasons on both my systems but mainly to clean up the bass on the sub woofers (no possibility of room treatments) on the main system phase and filter settings together with some positional adjustment have reduced the 30Hz excess and a nasty 40Hz dip to less to IMHO acceptable levels less than 6dB for each with the system running flat (no enhancements like dynamic eq enabled).

What you propose above is exactly what I have been doing and 75dB is what I use 80dB and above is too high for me. I note your noise floor is roughly 50dB that is a little higher than mine which on a good day (wind in right direction so no aircraft) is around 41 to 43dB. I mention this because I find the higher the noise floor the more it affects the distortion results and on a bad noisy day with the noise floor above 50dB I can't get reasonable consistency for distortion results which can appear unacceptably high all around the lower quarter of the frequency response one minute and better the next. Today should be a good day and some sweeps are proposed the wind is in the South :smile: (we are on the Southern flight path) so should be no aircraft all will be approaching from the North.
Best of luck with your endeavours
 

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...Today should be a good day and some sweeps are proposed the wind is in the South :smile: (we are on the Southern flight path) so should be no aircraft all will be approaching from the North.
Best of luck with your endeavours
what a coincidence.. I live on Long Island NY close to Islip airport and Southwest Airlines' flight path is directly over my house. I have to do most of my measuring at night in order to avoid the loud planes interfering with the readings!
 

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John and others,

I'm not sure if this has been brought up already, but I figured I would share it anyway so that others can avoid frustration when using the acoustic time reference feature in REW with an AVR like mine. My issue was that I was not getting the timing reference signal even though I selected it.

My AVR is a Pioneer Elite SC-99. when I plug in the HDMI cable from the laptop to the front port (HDMI 5), the signal is processed as PCM and the auto surround feature defaults to Dolby Surround which is their new decoder that was created with Dolby Atmos. For whatever reason, having Dolby Surround as the default was blocking the timing reference signal, and REW would sit there waiting indefinitely for the signal, if prior to the measurement I checked off the box that tells REW to wait for the timing reference signal. If I didn't check off that box, the measurement would take place but I would get a pop up notice from REW saying that the reference signal was not detected and the results would be inaccurate/ incomplete.
I spent a good deal of time researching to see if anyone else was reporting this as an issue, but I found nothing. I even reinstalled the software just to be certain that it wasn't a loading error of sorts.

I tried several decoder modes to no avail, until I finally set the decoder to PURE DIRECT which removes all processing. Upon doing so, the reference signal became audible and REW was able to detect it. I switch back and forth between Pure Direct and the other modes and the outcome was the same everytime.

So if anyone is having an issue with the timing reference signal, please check your AVR and make sure that it is set to Pure Direct or its equivalent on your AVR.
 

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I have bought this microphone and made my first measurements. And it worked without any problems.

But now i have a bunch of measurements but need to analyze them?! Maybe need to start a new thread. :)
 

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I have bought this microphone and made my first measurements. And it worked without any problems.

But now i have a bunch of measurements but need to analyze them?! Maybe need to start a new thread. :)
Great a tip that someone told me here was to do a measurement from the Listening position with the left speaker only and then the Right speaker only then both together.

Also do not just post a pic of your measurements also upload the Mdat file we can load it into REW and pull data that you had no idea was there. Must people new to this this just look at the frequency response but that is not really that useful if you are trying to fix problems.
 
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