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my measurements, advice needed
Old 22nd July 2020
  #1
Gear Nut
 

my measurements, advice needed

Hello all

i need advice regarding monitor position in small room,

my room is 4.9meters in lenght 3meters wide, and has slanted ceilings, lowest part where my monitors stand height is 1.97 meters, and back wall where window is ( in the middle) its 2.39m

all four corners has soffit bass traps, i have custom panels (18cm) but not yet placed, just free standing.

i am using REW RTA mode to find best position, and then do sweeps, after long back and forht i think i found the best (maybe) position in my room.

There are problems but im realistic and i know that its maybe impossible to treat 1-0-0 mode witch is about 35hz ( super loud)

there are super sharp dips, maybe SBIR related? cloud would help?


so im attaching mdat file, hope to get some feedback

Thank you all
Attached Thumbnails
my measurements, advice needed-20200722_192018.jpg  
Attached Files
File Type: mdat ged_2020_07_22_bass traps.mdat (4.49 MB, 23 views)
Old 25th July 2020
  #2
Good L+R symmetry. To treat the 35 Hz, you'll probably need to go much deeper on the rear wall or go for tuned absorbers (GIK Scopus).

The hole around 165 Hz may be ceiling related? Do you have anything on the ceiling? Impulse report doesn't look like it.

The loud reflection at 8.6 ms is what?

Overall, I think not a bad start.
Old 26th July 2020
  #3
Gear Nut
 

Quote:
Originally Posted by johannburkard View Post
Good L+R symmetry. To treat the 35 Hz, you'll probably need to go much deeper on the rear wall or go for tuned absorbers (GIK Scopus).

The hole around 165 Hz may be ceiling related? Do you have anything on the ceiling? Impulse report doesn't look like it.

The loud reflection at 8.6 ms is what?

Overall, I think not a bad start.
Thank you Johannburkard for your response

No theres nothing on the ceiling yet, my next move is putting the cloud

i have made more measurements by placing more panels on the front wall, it does something to 200 region but it creates small dip at 67,

will those panels make sense on the front wall?

and that 100 dip is there no matter monitor or mic placement..
Attached Thumbnails
my measurements, advice needed-20200726_163631.jpg   my measurements, advice needed-20200726_164147.jpg  
Attached Files
File Type: mdat gd_2.mdat (5.98 MB, 1 views)
Old 30th July 2020
  #4
Gear Nut
 

did some more testing.. panels on front wall deals with reflection around 6ms, but does nothing to reflection around 2.4ms is that ceiling? hard to test without committing to put panels there..

i have read that no need for panels on front wall in small room if monitors touching the wall, but it deals with loud 200hz region well but sharpens null at 150..

next thing is the cloud, ceiling is really low at this position so my cloud would be limited but any cloud is better than no cloud i think.

any more opinions would be greatly appreciated
Attached Files
File Type: mdat gd_3.mdat (3.90 MB, 4 views)
Old 30th July 2020
  #5
The decay in the last measurement looks cleaner and less spi_key than your first measurements. If you want to experiment with ceiling treatment look at Basotect, it doesn't really weigh anything.

BTW: Please always measure L+R separately.

Last edited by johannburkard; 30th July 2020 at 09:40 AM.. Reason: Hmm?
Old 3rd August 2020
  #6
Gear Nut
 

Hello i made more measurements with cloud and front panels, and no panels, front panels deals with some dips and reflections, but deepens null at 144.5 its super sharp..and im not making it disappear by moving mic and speakers... i think its the best position at the moment.

But i think i need to live with compromise, and to me (im not an expert on acoustics) i think front panels makes more sense...

Any thoughts would be greatly appreciated.

Thank you
Attached Files
File Type: mdat 2020-08_gd.mdat (11.71 MB, 4 views)
Old 3rd August 2020
  #7
There is a new reflection at around 1 ms which is usually a desk reflection. Did you set up a desk in the room now?

For me the "both" measurement looks the best, just maybe a bit thin in the bass.

The hole is now at 142 Hz which is less than where it was previously, I think. If the frequency changes, it's probably interference, maybe with the ceiling?

Not sure but maybe the room is starting to become too dead so maybe you want to add some diffusion at some point.
Old 3rd August 2020
  #8
Gear Nut
 

Quote:
Originally Posted by johannburkard View Post
There is a new reflection at around 1 ms which is usually a desk reflection. Did you set up a desk in the room now?

For me the "both" measurement looks the best, just maybe a bit thin in the bass.

The hole is now at 142 Hz which is less than where it was previously, I think. If the frequency changes, it's probably interference, maybe with the ceiling?

Not sure but maybe the room is starting to become too dead so maybe you want to add some diffusion at some point.
Thank you for the response

Yes iv got table there and its not big, 1meter in width, probably need to deal with table reflections,

i have managed to change the dip, with moving closer to the wall, i dont know if this made some significant difference, but the null smaller now...but a bit broader

probably the best i can do right now, or do i need to revert back
Attached Files
File Type: mdat 2020-08_closer to wall.mdat (5.86 MB, 1 views)
Old 3rd August 2020
  #9
Quote:
Originally Posted by gedna View Post
Thank you for the response

Yes iv got table there and its not big, 1meter in width, probably need to deal with table reflections,

i have managed to change the dip, with moving closer to the wall, i dont know if this made some significant difference, but the null smaller now...but a bit broader

probably the best i can do right now, or do i need to revert back
A null that is a narrow and deep is actually favorable to one that is broad and not as deep.
Old 3rd August 2020
  #10
Gear Nut
 

Quote:
Originally Posted by thethrillfactor View Post
A null that is a narrow and deep is actually favorable to one that is broad and not as deep.
Thank you for the response, i will revert back to my previous position, thats probably the best position i can achieve right now (by just moving monitors and mic)
Old 4th August 2020
  #11
Gear Nut
 

Hello

I have made one adjustment regarding speaker placement, i put monitors upside down and i think ( im not an expert regarding acoustics and REW reading) i getting better results,( still got that table reflection, but i will deal with it later) there are some dips and peaks but not that noticeable, like super sharp notches and have to say its more pleasant sound now.

manual says nothing about monitor placement upside down, (though it says placing them horizontally is permissible maybe try that?)

Tweeters now facing exactly my ear level.

any opinion is greatly appreciated
Attached Files
File Type: mdat 2020_upside_down.mdat (5.86 MB, 2 views)
Old 6th August 2020
  #12
Gear Nut
 

bump!
Old 18th August 2020
  #13
SPL symmetry is pretty good.

Yes, the desk reflection is still there. As long as you can identify it, good. Maybe a smaller 15 cm Basotect panel could help to a bit?

Ceiling still untreated?

Overall, a bit of bass boost should help.

You should still add treatment to the rear wall to even out the 40-60 Hz zone.
Old 18th August 2020
  #14
Gear Nut
 

Quote:
Originally Posted by johannburkard View Post
SPL symmetry is pretty good.

Yes, the desk reflection is still there. As long as you can identify it, good. Maybe a smaller 15 cm Basotect panel could help to a bit?

Ceiling still untreated?

Overall, a bit of bass boost should help.

You should still add treatment to the rear wall to even out the 40-60 Hz zone.
Thank you for your reply.

Yes reflections is edges of the desk, im thinking maybe to put the desk on an angle somehow,

I have light treatment on the ceiling and it helped with reflections and loud 200ish region

on the back i have 2 bass traps (soffit) in the corners, and the window in the middle, i covered it with acoustic curtain,

So you think back treatment would help to bring that hole in 60hz up?

Thank you
Attached Thumbnails
my measurements, advice needed-20200818_083103.jpg  
Old 18th August 2020
  #15
Quote:
Originally Posted by gedna View Post
So you think back treatment would help to bring that hole in 60hz up?
It could, yes, if your treatment works down to those frequencies. What treatment will do is to reduce modal strength. Here is a recent example when I added more Caruso Iso-Bond WLG040 to my rear wall.
Attached Thumbnails
my measurements, advice needed-before-after-more-rear-wall-treatment.jpg  
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