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high frequency breakup? aka what's happening in my room at HF?

mkawa

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#1
I just got my umik-1 calibrated in REW and I'm getting the same high frequency noise I was getting last week with my blue yeti. Basically, my room likes this

https://www.dropbox.com/s/hka02ykafrj0nky/Screen Shot 2021-04-10 at 3.29.22 PM.png?dl=0

I keep seeing other people with really clean HF SPL graphs and i'm wondering if their REW setup is better or if I'm really getting a ton of HF breakup in my room and why? it is, to be fair, a mess of an office with no treatment, but if there's something simple i can do (other than clean up, that's impossible) with regard to monitor placement, suggestions would be awesome. my monitor placement is on my desk as such:

https://photos.app.goo.gl/oTKt1CVgd3yveLqq7
 

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RayDunzl

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#4
My analysis:

It's phase cancellations, from sound reaching the microphone at different times due to path differences as it bounces around the room.

Measure very close to the speaker and it will disappear.

Or get speakers that don't spray the room with sound.

I have JBL LSR 308 wide dispersion and Martin Logan electrostats narrow dispersion.

No smoothing, at the mic location. Red, JBL, black ML

1618092824356.png


1/6 smoothing

1618092875949.png
 
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M

mkawa

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Thread Starter #5
interesting... these are 8040s that i'm using i'm committed to keeping, but i'm also moving twice in the next few months, so i'm thinking of investing in room treatment for both my living room system (dirac with a 22?) and this office system depending on how much of a mess it is. i thought i'd be able to avoid these kinds of reflections from using them nearfield but it sounds like that's not happening.

it's not time delay dispersion reflections. here's a measurement directly from the left woofer (in red)

https://www.dropbox.com/s/wgdffo88yfsxxb5/Screen Shot 2021-04-10 at 10.57.09 PM.png?dl=0
 
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