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FR vs Waterfall chart for analyzing room measreuments
Old 9th September 2019
  #31
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Quote:
Originally Posted by camomiletea View Post
Did you see the drawing above of my studio? I think you didn't see it because there you can see that all the walls are absorption. The speaker even up against the wall is not up against the wall because there is a layer of absorption behind it 40cm thick.
If your absorption has thickness x, the woofer is distance x + the depth of the cabinet away from the wall, so the thickness of the absorption is insufficient.
It's way better to flushmount the speaker in the absorption or flushmount it with rigid materials.
Old 9th September 2019
  #32
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Quote:
Originally Posted by dinococcus View Post
Do you hear the deep and the bump?

For the high frequency, it's not a question of treatment but
1) the mic not towards to the acoustical axis of the speakers
Or
2) the tweeter or the mic have an issue.
I was pointing the mic at the ceiling. Is this why the high frequencies are lower?

So could you tell me what steps you would take if this was your room? Would you be happy with these results?
Old 9th September 2019
  #33
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Smile

Quote:
Originally Posted by bert stoltenborg View Post
If your absorption has thickness x, the woofer is distance x + the depth of the cabinet away from the wall, so the thickness of the absorption is insufficient.
It's way better to flushmount the speaker in the absorption or flushmount it with rigid materials.
40cm thick bass traps are insufficient? Yes i have heard the dogma of flush mounting but I have also heard that it can be done this way with good results
Old 9th September 2019
  #34
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Quote:
Originally Posted by camomiletea View Post
I was pointing the mic at the ceiling. Is this why the high frequencies are lower?

So could you tell me what steps you would take if this was your room? Would you be happy with these results?
The mic pointed towards the acoustical axis.

I am an eternal dissatisfied so only can answer.
Old 9th September 2019
  #35
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Quote:
Originally Posted by dinococcus View Post
The mic pointed towards the acoustical axis.

I am an eternal dissatisfied so only can answer.
Haha. An eternal dissatisfied. Thay is funny but I think all of us on this forum are. I was trying to ask you if you think I can do anything to improve the acoustics?
Old 9th September 2019
  #36
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Quote:
Originally Posted by akebrake View Post
For a start we have to find out if your measurements are valid.
Then we can go into detail. (The first one looks a bit strange IMHO)

Pls upload your mdat here

Best
Have you abandoned me?
Old 9th September 2019
  #37
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akebrake's Avatar
 

Quote:
Originally Posted by camomiletea View Post
Have you abandoned me?
No, I am comparing all the measurements (which takes time, sorry) and I also trying to compose some clever answers to your questions.

BTW. Your omni is quite large (for being a makeshift "measurement" mic) so I agree with Dino pls point them tow the acoustical axis of the speaker measured.

EDIT: Acoustical Center is a better description.

90° off means large hi end roll off (and a false impulse also)

I am afraid all of your earlier measurements are not valid above
say 1500 Hz...

Lessons learned:

Point 3 in my list: Microphone problems. I forgot to specify angle, sorry

Without knowing the position of speakers, microphone type and angle, surrounding objects (krk spkr) spkr shelf, desk...one can just say: the impulse looked strange.
Now we probably have an explanation.

Best

BTW Bass is better w spkr closer to the front wall.

Last edited by akebrake; 10th September 2019 at 10:39 AM..
Old 9th September 2019
  #38
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Quote:
Originally Posted by akebrake View Post
No, I am comparing all the measurements (which takes time, sorry) and I also trying to compose some clever answers to your questions.

BTW. Your omni is quite large (for being a makeshift "measurement" mic) so I agree with Dino pls point them tow the acoustical axis of the speaker measured.

90° off means large hi end roll off (and a false impulse also)

I am afraid all of your earlier measurements are not valid above
say 1500 Hz...

Lessons learned:

Point 3 in my list: Microphone problems. I forgot to specify angle, sorry

Without knowing the position of speakers, microphone type and angle, surrounding objects (krk spkr) spkr shelf, desk...one can just say: the impulse looked strange.
Now we probably have an explanation.

Best

BTW Bass is better w spkr closer to the front wall.
Ok grand. Just a quick question. The acoustical axis is where my eyes point towards when i am mixing or do I point the mic directly toward the cone of the speaker ?
Old 9th September 2019
  #39
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On a two-way the acoustical axis is the mid point between the center of the woofer and the center of the tweeter.
Old 9th September 2019
  #40
Old 9th September 2019
  #41
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Rectification of my stupidity: microphone points to the ceiling and at the height of the acoustical axis.

Sorry
Old 9th September 2019
  #42
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Quote:
Originally Posted by camomiletea View Post
It's wrote : speakers measurements not room measurements but this is the good drawing of the acoustical axis.
Old 9th September 2019
  #43
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Quote:
Originally Posted by dinococcus View Post
It's wrote : speakers measurements not room measurements but this is the good drawing of the acoustical axis.
Yes but Akebrake said to point the microphone at the acoustic axis and i didnt know what that was. So i found that page which shows what the acoustic axis is. I took a picture. Can you or Akebrake please clarify if i am pointing the mic in the right place
Attached Thumbnails
FR vs Waterfall chart for analyzing room measreuments-20190909_223244.jpg  
Old 9th September 2019
  #44
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Quote:
Originally Posted by camomiletea View Post
40cm thick bass traps are insufficient? Yes i have heard the dogma of flush mounting but I have also heard that it can be done this way with good results
Don't let Thomas hear you or your ass is fried.

But if you try to have a nice room some rules have to be obeyed.
Old 9th September 2019
  #45
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Quote:
Originally Posted by bert stoltenborg View Post
Don't let Thomas hear you or your ass is fried.

But if you try to have a nice room some rules have to be obeyed.
Who is Thomas.?
Old 9th September 2019
  #46
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Quote:
Originally Posted by camomiletea View Post
Who is Thomas.?
Thomas is the final boss in this game.
Old 10th September 2019
  #47
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Quote:
Originally Posted by camomiletea View Post
Yes but Akebrake said to point the microphone at the acoustic axis and i didnt know what that was. So i found that page which shows what the acoustic axis is. I took a picture. Can you or Akebrake please clarify if i am pointing the mic in the right place
You measured the height of the mic and the height of the acoustical axis. They must be the same.
Old 10th September 2019
  #48
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Quote:
Originally Posted by camomiletea View Post
Yes but Akebrake said to point the microphone at the acoustic axis and i didnt know what that was. So i found that page which shows what the acoustic axis is. I took a picture. Can you or Akebrake please clarify if i am pointing the mic in the right place
The mic must be vertical. You do not measure the speaker.
Old 10th September 2019
  #49
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Quote:
Originally Posted by dinococcus View Post
The mic must be vertical. You do not measure the speaker.
Like this?

This is how i had it before and Akebrake said my measurements were not valid above 1500khz. Did you read his last post?
Attached Thumbnails
FR vs Waterfall chart for analyzing room measreuments-20190910_082143.jpg  
Old 10th September 2019
  #50
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Jason Foi's Avatar
 

Quote:
Originally Posted by bert stoltenborg View Post
Thomas is the final boss in this game.


Old 10th September 2019
  #51
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Quote:
Originally Posted by camomiletea View Post
Like this?

This is how i had it before and Akebrake said my measurements were not valid above 1500khz. Did you read his last post?
The issue above 1500 is not due to the position of the mic but to the mic himself, maybe.

If what i see on the picture is a mic, yes.
Old 10th September 2019
  #52
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Quote:
Originally Posted by dinococcus View Post
The issue above 1500 is not due to the position of the mic but to the mic himself, maybe.

If what i see on the picture is a mic, yes.
I tried both mics. I have two. They are a matched pair and they came with a test which shows their FR. I dont see how it can be the microphones because the FR looks quite fIat. I hope Akebrake can come to the rescue because I am not sure if I have to take more measurements or not. I dont know what to make of his last post anymore to be honest. It all seems very confusing.
Old 10th September 2019
  #53
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Jason Foi's Avatar
 

Up or down isnt that important. Both results will be similar. I have not looked ar your mdat, but your HF problems were probably due to measuring L&R at the same time, or being off axis.
Old 10th September 2019
  #54
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Quote:
Originally Posted by Jason Foi View Post
Up or down isnt that important. Both results will be similar. I have not looked ar your mdat, but your HF problems were probably due to measuring L&R at the same time, or being off axis.
Speakers were measured seperately as in the photo i just posted above. Pointing up at the ceiling and at the height roughly where my ears are ( height of the tweeter)
Old 10th September 2019
  #55
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Quote:
Originally Posted by dinococcus View Post
The issue above 1500 is not due to the position of the mic but to the mic himself, maybe.

If what i see on the picture is a mic, yes.
What is the issue you see on the high end and from what frequency?
Old 10th September 2019
  #56
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Tuesday measurements

Ok so I did 4 new measurements (only on the right speaker for now)because I am still not sure if I should be pointing the microphone at the ceiling or not. When I point it more toward the speaker dead on the acoustic axis the high end gets better. Why is this? You can see how the high end starts rolling off the more I tilt the mic toward the ceiling. Can someone please explain why this happens? does anyone actually know the answer ?

The charts are labeled "0 degrees", 30 "degrees", "60 degrees" and "90 degrees". the one which is named "0 degrees" is parallel to the floor and pointing directly at the acoustic axis while the other ones are all variations turning the microphone upwards toward the ceiling 30 degrees at a time until the last one where the mic is pointing directly towards the ceiling.

can anyone please explain why this happens?
Attached Thumbnails
FR vs Waterfall chart for analyzing room measreuments-0degrees.jpg   FR vs Waterfall chart for analyzing room measreuments-30degrees.jpg   FR vs Waterfall chart for analyzing room measreuments-60degrees.jpg   FR vs Waterfall chart for analyzing room measreuments-90degrees.jpg  
Old 10th September 2019
  #57
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here is one with overlay so you can compare the results. Look at the red one! The high frequency is more linear and it starts to drop off the more you turn the mic upward. Should I still measure using the microphone pointed at the ceiling? obviously there is big difference in HF that way.
Attached Thumbnails
FR vs Waterfall chart for analyzing room measreuments-overlay.jpg  
Old 10th September 2019
  #58
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In a different speaker position, I did another comparison because I like the bass response more

BLUE = 0 degrees parallel with floor pointing right at the speaker
GREEN= 90 degrees parallel with walls pointing right at the ceiling
Attached Thumbnails
FR vs Waterfall chart for analyzing room measreuments-new.jpg  
Old 10th September 2019
  #59
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In this one the bass is completely flat up to a certain point but overall I think it is pretty good. Hoping someone else can chime in before I start drawing crazy conclusions. Again the mic pointing up is completely lacking high end. I still don't know what this actually means. Since it is an omni shouldnt it be picking up high frequency upright just as it does pointing at the source?
Attached Thumbnails
FR vs Waterfall chart for analyzing room measreuments-bestbass0degrees.jpg   FR vs Waterfall chart for analyzing room measreuments-bestbass90degrees.jpg  
Old 10th September 2019
  #60
Lives for gear
The size of the mic. What is the diameter of the body of the mic?

Pointed to the speakers, the mic is transparent.
Pointed to the celling, the body of the mic traine diffractions in the high.
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