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My great room acoustics
Old 20th October 2019
  #1
Here for the gear
 

My great room acoustics

Hi,

I wanted to share with you a measurement from today.
Please let me know if you have any comments
This is the before. I haven't really treated the room yet. Will start next week doing it.

Any tips from you guys?

Ronny
Attached Thumbnails
My great room acoustics-rew-1.jpg  
Old 20th October 2019
  #2
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akebrake's Avatar
 

Quote:
Originally Posted by Ronnymonkey View Post
Hi,

I wanted to share with you a measurement from today.
Please let me know if you have any comments.
If you upload your mdat file here we can help you interpret your measurement.

Best
Old 20th October 2019
  #3
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Quote:
Originally Posted by akebrake View Post
If you upload your mdat file here we can help you interpret your measurement.

Best
ok!

By the way. I used an AKG 214 for the measurement.
Attached Files
File Type: mdat rew1.mdat (4.61 MB, 9 views)
Old 20th October 2019
  #4
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akebrake's Avatar
 

Use omni for measurements

Quote:
Originally Posted by Ronnymonkey View Post
ok!

By the way. I used an AKG 214 for the measurement.
That's a bit unfortunate because AFAIK that mic is a cardioid.
So these measurement will not tell us very much...
For room measurements we like to see reflections from all directions.

E.g Acoustical Measurements are usually done with small omni-microphones.
Such a beast can be bought for around 70-100 USD.

Best
Old 20th October 2019
  #5
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Quote:
Originally Posted by akebrake View Post
That's a bit unfortunate because AFAIK that mic is a cardioid.
So these measurement will not tell us very much...
For room measurements we like to see reflections from all directions.

E.g Acoustical Measurements are usually done with small omni-microphones.
Such a beast can be bought for around 70-100 USD.

Best
Yes, I will do that. Thanks. Just so YOU can read it
Old 21st October 2019
  #6
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Quote:
Originally Posted by Ronnymonkey View Post
Yes, I will do that. Thanks. Just so YOU can read it
?
He's giving you good advice! He's also one of the few REW experts around here....

Studio acoustic measurements should always be done with a proper measurement mic, and they are not expensive. It has to be omni because, as akebrake says, the mic has to pic up sound equally in all directions, not just concentrated in one single direction. It also has to be a small mic (not a large diaphragm mic) so that the body of the mic itself does not interfere with the sound waves it is trying to measure.

Here's a tutorial on how to set it all up and do the measurements. How to calibrate and use REW to test and tune your room acoustics There are several issues with your MDAT measurements that make the data you posted not very useful. About the only thing that can be discerned from that data is that the room is empty, you have some modal issues, flutter echo, and there are several very strong early reflections. If you follow those instructions, you'll be able to produce REW data that can be used to analyze your room in far more detail.

- Stuart -
Old 21st October 2019
  #7
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Quote:
Originally Posted by Soundman2020 View Post
?
He's giving you good advice! He's also one of the few REW experts around here....

Studio acoustic measurements should always be done with a proper measurement mic, and they are not expensive. It has to be omni because, as akebrake says, the mic has to pic up sound equally in all directions, not just concentrated in one single direction. It also has to be a small mic (not a large diaphragm mic) so that the body of the mic itself does not interfere with the sound waves it is trying to measure.

Here's a tutorial on how to set it all up and do the measurements. How to calibrate and use REW to test and tune your room acoustics There are several issues with your MDAT measurements that make the data you posted not very useful. About the only thing that can be discerned from that data is that the room is empty, you have some modal issues, flutter echo, and there are several very strong early reflections. If you follow those instructions, you'll be able to produce REW data that can be used to analyze your room in far more detail.

- Stuart -
Yes! I know ?
I’m buying a mic for it. I wasn’t sarcastic hahahah
I’m very grateful for the help. I found a Omni directional from behringer for 31 euros. Will order it and get back here.
Old 21st October 2019
  #8
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Starlight's Avatar
 

Quote:
Originally Posted by Ronnymonkey View Post
I found a Omni directional from behringer for 31 euros.
So you didn't read Stuart's link. What a pity.
Old 21st October 2019
  #9
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Behringer ECM8000 are not always very bad....
Old 21st October 2019
  #10
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Quote:
Originally Posted by Starlight View Post
So you didn't read Stuart's link. What a pity.
I'm at work. Didnt read the link sorry. Now i've read it. I will look for the other mic.I will come back later.
Old 21st October 2019
  #11
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akebrake's Avatar
 

Quote:
Originally Posted by Soundman2020 View Post
?
He's giving you good advice! He's also one of the few REW experts around here....

Studio acoustic measurements should always be done with a proper measurement mic...
Thanks Stuart for the kind words.
I have found this and other acoustical Forums very interesting and inspiring learning places and want to give something in return. Learning is fun!

So many different rooms and folks struggling with their room measurements. Comparing thousands and trying to find out what’s wrong is a good exercise.
(But honestly, I have a suspicion the ”teacher”will learn the most... )

A strength here is that so many members use the same software (REW) which means we have a common platform and can discuss results and different ways to tweak or present the results.
That would be quite tricky if members use many different acoustical software.

@ Ronny
In addition to Stuarts comments about a typical measured empty room result,
I found your first measurement heavily distorted for some reason.
Total Harmonic Distortion (THD) is around 10% (≈20dB below fundamental) See pic below.
May be you’re sweeping too loud (with small loudspeakers), or the signal is clipping?

RE measuring microphones. Cheap and precission don’t usually go together.
Does it matter if the mic is +/- 5dB across the audible range?

All gear have tolerances. It depends how picky you are...
A 100 € mic will be fine for the job if supplied with a calibration file.

Be prepared to make many measurements and minimize risk to drop your more expensive 214.

Cheers
Attached Thumbnails
My great room acoustics-hi-dist-20db-down.jpg  

Last edited by akebrake; 21st October 2019 at 05:24 PM.. Reason: Sorry, Typo
Old 21st October 2019
  #12
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Quote:
Originally Posted by bert stoltenborg View Post
Behringer ECM8000 are not always very bad....
True. Sometimes you get lucky.

- Stuart -
Old 22nd October 2019
  #13
Here for the gear
 

Quote:
Originally Posted by akebrake View Post
Thanks Stuart for the kind words.
I have found this and other acoustical Forums very interesting and inspiring learning places and want to give something in return. Learning is fun!

So many different rooms and folks struggling with their room measurements. Comparing thousands and trying to find out what’s wrong is a good exercise.
(But honestly, I have a suspicion the ”teacher”will learn the most... )

A strength here is that so many members use the same software (REW) which means we have a common platform and can discuss results and different ways to tweak or present the results.
That would be quite tricky if members use many different acoustical software.

@ Ronny
In addition to Stuarts comments about a typical measured empty room result,
I found your first measurement heavily distorted for some reason.
Total Harmonic Distortion (THD) is around 10% (≈20dB below fundamental) See pic below.
May be you’re sweeping too loud (with small loudspeakers), or the signal is clipping?

RE measuring microphones. Cheap and precission don’t usually go together.
Does it matter if the mic is +/- 5dB across the audible range?

All gear have tolerances. It depends how picky you are...
A 100 € mic will be fine for the job if supplied with a calibration file.

Be prepared to make many measurements and minimize risk to drop your more expensive 214.

Cheers
Thanks Akebrake, i will pick up a good measurement mic and get back on it. Once i do another measurement i will report the results in this thread. Very thankfull for the help and i'm hoping on a pleasant experience for all of us.

Peace to all.
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