[Help] How to best use graphs? How to interpret them? [ECM 8000 microphone]

[Fajele]

Hello Kind Supporters,

I I've heard about Room EQ Wizard from Video Gik Acoustic and recently I use it and I would like to understand how to use it at its best and for the bare minimum. I have studied the whole REW manual and I took a look at the guides that John Mulcahy pointed out to me to me but unfortunately I still have doubts ... I using REW to acoustic treatment my project studio and currently there are only two superchuncks in the corners behind audiodesk. I would like to have sensitive data but I have not understood what I read and how I should interpret the data and which data and graphs I have to take into consideration and if there are particular any window display functions that I have to set.
I currently use a Focusrite 18i20 soundcard and a behringer ECM8000 and currently I have calibrated only the sound card for frequency response compensation but I don't know how I should calibrate the ECM 8000 microphone.

I'll post you screenshots of all graph,

Spoiler: screenshots

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I ask you kindly:

• I don't use a Ref In signal (because I didn't understand the usefulness and how to use it) but I just calibrated the sound card using a loopback, now the preferences panel settings are correct?
• How can I calibrate my microphone?
• 
  
• What are the graphs that I have to consider for my objective and how should I interpret them? and what window settings should I set to have more readable data?

John Mulcahy for my request suggest me to write here,
I await your kind reply!

 

[simplex]

Hi Fajele,

Let me first say that I'm a total newbie to REW myself, just started less than 2 weeks ago trying to optimize my listening room = living room. So take everything I can say with a grain of salt.

Compared to my own situation, your SPL curve looks really great! Mostly flat between 30 Hz and 20 kHz.

What possibly asks for some attention is that room mode around 32 Hz, the rest of the spectrum looks perfect to me. I doubt that you can muffle these by absorbers, unless you're going really huge.

For my living room situation, I was able to generate .wav filters in REW which I then imported in my Daphile server. It works absolutely great after several attempts 'learning by doing'. But your studio situation and use case is probably very different, so other rules may apply.

It would certainly be helpful for the specialists if you attached more detail about your room and your equipment: a sketch of the room including relevant furniture, speaker placement, etc.

I'm using the Behringer ECM8000 also, and I think it's flat enough to work for detecting room modes without calibration. My audio interface is a Steinberg UR12, which I chose because of its Linux compatibility and good price.

I wish you good success and fun on your way!

 

[Fajele]

Thank you for your kind reply,
I kindly ask for clarification to understand some thing

• Currently I kindly need to understand how how should I interpret, how should I read them
• and what are the most important graphs to consider for acoustic treatment
• how to use the windows setting for read the data well
• and I would like to understand if for my case the preference panel is set correctly and if I need a calibration file and how I can calibrate my ecm8000 (for the moment I have only calibrated the sound card)

thank you in advance for a kind reply!
I attach the files better

 

[Fajele]

I attach the REW file

 

[pklose]

Hi Fajele,

let me try to answer your questions:

• Currently I kindly need to understand how how should I interpret, how should I read them
  • The "SPL and Phase" and "All SPL" shows you the sound pressure level over frequency at your measurement point. Since you are measuring a room, a single measurement contains not enough data to make a qualified judgement. Take for to six measurments at and around your listening (30 to 60cm apart, also differ the heights slightly 5 to 10cm). Average the measurements in All SPL, smooth the graph to 1/24th (experienced engineers setting) or 1/12th (advanced) or 1/6th (easy to understand)
• and what are the most important graphs to consider for acoustic treatment
  • for room modes: the SPL dips and hills in the freq range smaller 300 Hz. Also: Reverberation time (RT60 tab in REW). Looks like your room is very empty and untreated (concrete walls and hard floors?).
• how to use the windows setting for read the data well
  • not important when you are trying to understand your room. This is only important when you want exclude the room from your investigation.
• and I would like to understand if for my case the preference panel is set correctly and if I need a calibration file and how I can calibrate my ecm8000 (for the moment I have only calibrated the sound card)
  • Which preference are you not sure of? There a few in REW? If you want to calibrate The absolute level of your, get a pistophone. I am using one from gain express. It is supposed to deliver 94 dBSPL and does 92,5 dBSPL in realtiy. But I am fine with that, that is close enough. If you want to have a relative correction (all freqs correct) I am afraid you must go for a higher end mic with a calibration file included.

I hope that helped.

--
Best regards
Philipp

 

[Fajele]

Hi kind pklose

thanks for the answer now it is clearer to me and

• Take for to six measurments at and around your listening (30 to 60cm apart, also differ the heights slightly 5 to 10cm)

As soon as I get back to the studio I will do 6 different measurements as you told me

• for room modes: the SPL dips and hills in the freq range smaller 300 Hz.

ok, I see room modes in the graph and in what case the modalities are well distributed, I mean, by what criteria do I see if they are well distributed or badly distributed??

• Also: Reverberation time (RT60 tab in REW). Looks like your room is very empty and untreated (concrete walls and hard floors?)

I haven't done an acoustic treatment yet there are only superchunck behind audiodesk, I would like to understand the graphs well first,

In the RT60 graph I see that there are values like:
Topt, EDT, T20, T30, TS, T60 ... umm which ones should I consider? Are there any major differences?


Okay, so it seems to me understand in this moment that you suggest to me look at the SPL and Phase and RT60 graph
and if it possible I would like to understand, could you give me some suggestions on the reading/interpretation of the other graphs? ( as Distortion, Impulse, IR Filtered, GD, RT60 Decay, Clarity, Decay, Waterfall, Spectogram)

Thank you so much!

 

[Fajele]

I think this topic could be of help to other future users too

 

[Fajele]

UP
Thank you