REW Beta Release Message stating high distortion

JIm586music

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Hello, Very new user here.
I'm using a MacBook Pro 2015 Monterey 12.7.6 and the latest REW beta.
I believe I'm all set up ok with the UMIk 1 however, after I take a measurement I get a box either saying I have high distortion or sometimes the signal to noise ratio is low.
I check the levels before each measurement (80db) and it says level ok.
what am I doing wrong?
Image 23-09-2024 at 11.25 pm.jpg


Thanks in advance.
Jim
 

John Mulcahy

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Speakers and subs may have high distortion at low frequencies, or the low end may be mostly noise. Easiest is to attach an mdat file from an example measurement.
 

JIm586music

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I will try and get my head around doing that tonight as the Mrs is out for Tai chi.
Cheers
 

JIm586music

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Hi John.
I'll attach the file. Hopefully its a minor issue.
Kind regards
 

Attachments

  • LFE L1 Sep 24.mdat
    600.6 KB · Views: 9

JIm586music

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As a an update.
I made a few subwoofer measurements at 85db last night and the error messages didn’t appear. They were obviously louder but I encountered an issue whereby I couldn’t align sbl( to calculate the average) without increasing the measurement on the graph to over 100db! Not sure if it was fatigue on my part but I was managing this with previous measurements.
Cheers
 

John Mulcahy

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The sub has a lot of 2nd harmonic distortion at around 25 Hz, but the measurement is otherwise OK.
 

JIm586music

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The sub has a lot of 2nd harmonic distortion at around 25 Hz, but the measurement is otherwise OK.
Hiya, thanks for the reply.
Ok, I’ll carry on then.
Ive tried again tonight and I don't get any error messages when I sweep with the subs at 85db?
I've moved the subs around. I have a Monoprice monolith 10' thx. this is the measurement I'm getting.
why is it rolling off from 40hz so much? is it normal or is my room?
cheers
 

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  • Left sub.jpg
    Left sub.jpg
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John Mulcahy

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The shape of the response will depend on the sub, your room, where the sub is in the room and where the mic is placed.
 

JIm586music

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Preamp, Processor or Receiver
Nad 578
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Tom Evans The Vibe
Additional Amp
Nad 298
DAC
Dennafrips Pontus 11
Universal / Blu-ray / CD Player
Panasonic 820
Streaming Equipment
Node 2i modded ps and rechecked
Front Speakers
Quadra Galan
Screen
P
Video Display Device
Projector Epson Ls12000b
The sub has a lot of 2nd harmonic distortion at around 25 Hz, but the measurement is otherwise OK.
Hiya, thanks for the reply.
Ok, I’ll carry on then.
I do wonder there’s a mic gain issue as it didn’t happen when I raised the level to 85db.
Cheers
The shape of the response will depend on the sub, your room, where the sub is in the room and where the mic is placed.
Thank you.
 
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