Need help with REW weird results

[Q-ster]

Hello dear community, I am a newb here !

I recently moved to another home studio and so I did some acoustic measurements in order to adapt the acoustic treatment and I am quite sceptical when I look at the results
What I mean by that is that, except from some modes below 200Hz, it looks already pretty good.

I measured the L speaker and the R speaker separately.

I've read that my RT60 should be between 200 - 300 ms, and it is already the case in most frequencies...

My idea now is to use some Caruso Iso-bond WLG 045 (3000 ps/m2. ) in that config : two 40cm thick pannels, In order to handle what's under 200hz.
And I wanted to add two Caruso Iso-bond WLG 035 (10000 ps/m2) : on the first reflections spot,10cm thick. But I'm afraid it will be too much absorption.

So my questions would be :

- Do you identify a problem in how I set up my measures ?

- Is my absorbtion idea legit ?


Thakn you so much for your time !



Just in case, here's the gear I used :

Soundboard : Audient ID44
Speakers : Genelec 8020
Meas. mic : Behringer ECM 8000

 

[kemmler3D]

You have a 10db swing from 500hz to 10khz, that's not good at all IMO. The rising response and quick drop after 10khz also makes me think there's a problem with the measurements because an 8020 doesn't do that by itself. I wonder if there's a problem with how you placed the mic or maybe the mic itself...

The decay times do look good but the FR not so much.

Also, if these measurements are accurate you should plan on using EQ in addition to the absorbers you mentioned. There's a 30dB swing at 150hz, maybe the worst I've seen. It will be hard to physically absorb enough bass to correct that.

 

[Q-ster]

Hello,

Thank you for your answer. I would agree that the measurement are not reliable. I followed some tutorials in order to have a proper mic placement and I already did those type of measures in my previous home and it worked fine.

The RT60 do look quite good, but that's what bothering me ; it is good even though I didn't put any sound treatment... it seems weird to me.

By the way, the measures I posted is just from the Left speaker.

 

[staticV3]

The ECM8000 IMO strays too much for use without a unique cal file:


Though not even that can explain your in-room response measurement. Something else is awry.

 

[kemmler3D]

The ECM8000 IMO strays too much for use without a unique cal file:
View attachment 449709

Though not even that can explain your in-room response measurement. Something else is awry.

That's a really helpful graph here, you can see that the swing from 500-1K - 10K is actually typical of the microphone. @Q-ster I think you should consider getting a UMIK-1 or having your mic calibrated.

As for the RT60... I wonder if you have any other mics you could compare this result with. Also, IIRC the ECM8000 has a really high noise level so maybe try running the sweep at a higher volume and see what happens.

 

[Keith_W]

Your RT60 target depends on your room size and application. Larger rooms = longer RT60 targets. Some can be as high as 800-1000ms for really large rooms. If you supply your room dimensions (don't forget height) I can calculate it for you.

Agree with what the others have said. There is something seriously awry with your measurements.

Thick red line = your measurement.
Green overlay = typical room target

Compare that to the measurements of the Genelec 8020 here on ASR. (look at the orange curve, for in-room response).

Your Genelec has tone controls. If you look at the manual on page 8, you will see what happens if you have your treble tilt at 0, and your bass tilt at maximum. You get an upward rising frequency response, but it's still only 6dB. Your tilt is about 10dB. Perhaps it's a combination of tone controls + uncalibrated mic that is giving you this result. Also, you can get this result if you are measuring too close to the speaker. Those speakers are designed to give a flat FR at 1m, and a downward tilting response at 2-3m - see the difference between "reference angle" and "in room response" in the spinorama shown above.

Suggest you check the dip switches and confirm the result with a borrowed mic.