Quantcast
How to Deal with a Room Where Symmetry is Impossible? - Page 2 - Gearspace.com
The No.1 Website for Pro Audio
How to Deal with a Room Where Symmetry is Impossible?
Old 2nd February 2013
  #31
Lives for gear
 
gullfo's Avatar
 
🎧 10 years
and if you extended the short right hand wall (relative to the desk - 3'10 1/4") another 4' or so you could improve the symmetry @ the desk. maybe some heavy gobos would do it.
Old 2nd February 2013 | Show parent
  #32
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
Quote:
Originally Posted by gullfo ➑️
and if you extended the short right hand wall (relative to the desk - 3'10 1/4") another 4' or so you could improve the symmetry @ the desk.
Actually, I didn't fully label the floorplan. That thing that looks like a long door along the west wall is really an open staircase. I think extending that short wall would actually unbalance the symmetry. ...unless I extended it from the north wall to essentially create two rooms, as was suggested earlier. But my tracking and rehearsal needs for the room kind of prevent that.
Old 2nd February 2013
  #33
Gear Guru
 
1 Review written
🎧 15 years
Good

Good work. Well done and presented. And well worth it IMO.
To my eye, both positions 2 and 3 are considerably better than the original 1.

When doing such comparative work I find it convenient to open all the measurements in a single .mdat file. Then, with your fine clear labelling, you can click on any pair or combination for very fast easy comparison.

DD
Old 2nd February 2013
  #34
Lives for gear
 
gullfo's Avatar
 
🎧 10 years
ok, thanks. wasn't clear on the opening stair. maybe there is an option for a door on that opening?
Old 2nd February 2013 | Show parent
  #35
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
Quote:
Originally Posted by DanDan ➑️
Good work. Well done and presented. And well worth it IMO.
Thanks. I definitely want to get this right.


Quote:
To my eye, both positions 2 and 3 are considerably better than the original 1.
That's kind of what I figured. I don't have a strong preference for one over the other. It might come down to which is practically easier to treat. It definitely looks like the status quo won't do, though.


Quote:
When doing such comparative work I find it convenient to open all the measurements in a single .mdat file. Then, with your fine clear labelling, you can click on any pair or combination for very fast easy comparison.
I'll try that. Thanks.

Any other comments by anyone are much appreciated.
Old 2nd February 2013 | Show parent
  #36
Gear Guru
 
1 Review written
🎧 15 years
ETC

You could take a look at the ETC's of 2 and 3. That might help decide.
BTW I haven't ever seen graphs like your Full Range SPL ones. Very wobbly at LF, smoothing to an almost flat line at HF. Is this some new feature in the new REW?
DD
Old 2nd February 2013 | Show parent
  #37
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
Quote:
Originally Posted by DanDan ➑️
You could take a look at the ETC's of 2 and 3. That might help decide.
OK, I've attached ETC graphs for each of the left and right speakers in both positions. What can I tell from these? My guess is more reflected energy overall in position 3, and it seems there's a bit of a spike in the reflected energy in position 2, particularly on the left speaker, due to the non-symmetry of the room. Am I reading that right?


Quote:
BTW I haven't ever seen graphs like your Full Range SPL ones. Very wobbly at LF, smoothing to an almost flat line at HF. Is this some new feature in the new REW?
That is weird. I have no idea what happened there. I've recharted and they look more normal. I'll upload the fixed versions.

EDIT: Done!
Attached Thumbnails
How to Deal with a Room Where Symmetry is Impossible?-etc-left-speaker-position-2-.jpg   How to Deal with a Room Where Symmetry is Impossible?-etc-right-speaker-position-2-.jpg   How to Deal with a Room Where Symmetry is Impossible?-etc-left-speaker-position-3-.jpg   How to Deal with a Room Where Symmetry is Impossible?-etc-right-speaker-position-3-.jpg  
Old 2nd February 2013 | Show parent
  #38
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
And here are comparison graphs of positions 2 and 3 by left speaker, right speaker and both, using 1/24 smoothing...
Attached Thumbnails
How to Deal with a Room Where Symmetry is Impossible?-spl-both-speakers-position-2-3-.jpg   How to Deal with a Room Where Symmetry is Impossible?-spl-left-speaker-positions-2-3-.jpg   How to Deal with a Room Where Symmetry is Impossible?-spl-right-speaker-position-2-3-.jpg  
Old 2nd February 2013 | Show parent
  #39
Gear Guru
 
1 Review written
🎧 15 years
Great

And the winner is .....

3 looks superior in all three FR graphs.
I reckon the ETC spikes will be easily treated.

Isn't REW something else!

DD
Old 2nd February 2013 | Show parent
  #40
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
Quote:
Originally Posted by DanDan ➑️
Isn't REW something else!
What's something else is that you can actually interpret that. My amateur guess would have been that 2 looked better, but I have no clue.

Much appreciated!
Old 2nd February 2013 | Show parent
  #41
Gear Guru
 
1 Review written
🎧 15 years
Dither

Could you present the Waterfalls in the same way for direct comparison?
As best I can tell I still prefer the 2 Waterfalls, but the 3 FR's look much better to me.
DD
Old 2nd February 2013 | Show parent
  #42
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
Quote:
Originally Posted by DanDan ➑️
Could you present the Waterfalls in the same way for direct comparison?
Here they are. Any scale or other adjustment I can make that would make them easier to read?
Attached Thumbnails
How to Deal with a Room Where Symmetry is Impossible?-waterfall-both-speakers-3-overlaid-2-.jpg   How to Deal with a Room Where Symmetry is Impossible?-waterfall-left-speaker-3-overlaid-2-.jpg   How to Deal with a Room Where Symmetry is Impossible?-waterfall-right-speaker-3-overlaid-2-.jpg  
Old 3rd February 2013 | Show parent
  #43
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
One other question...

I might have had the speakers a little closer together and a little closer to the wall than I'm likely to actually have them once I get everything re-setup in the new mix position with my new mix desk. Given that the measurements taken at Position 2 and Position 3 are relatively close, would it be worth re-doing the measurements at those two positions with the speakers more closely approximating where my speakers actually will end up being? It's only going to be a matter of inches away from where I already tested them, but as I said, I want to make sure I get this right.
Old 3rd February 2013 | Show parent
  #44
Gear Guru
 
1 Review written
🎧 15 years
Position

When optimising speaker and listener positions, 2 inch increments are often recommended. So yes, inches really do matter, and yes, even at LF.

There is confusion about regarding keeping speakers out from walls.
The biggest problems occur when they are out from the wall but not far enough. Quite often, almost touching the wall measures best. You can easily try this for yourself now.

Note REW has Periodic Pink Noise and an RTA. Zoom to 30-200Hz and you can perform many of these tests very quickly. e.g. Look at the RTA while moving the speaker or mic.

I would find it easier to compare Waterfalls if they were in the same sequence as you have been using. e.g. L(2) L(3) R(2) R(3) L+R(2) L+R(3)
The next and previous tabs skip between them nicely.

You are looking for a tie breaker in a very close call situation.

Perhaps you could try to find treatment which applies to both 2 and 3, and go ahead with that.

Rest easy however in the fact that you have avoided the worst area and that both good choices seem very close.

In this case I am leaning towards the better looking FR graphs rather than Waterfalls. This is because I am focussed on the harmful effects of nearby boundaries.

DD
Old 3rd February 2013 | Show parent
  #45
Gear Maniac
 
bonestar's Avatar
 
🎧 10 years
I feel like my ability to use REW and post meaningful results has grown significantly over the course of this thread. I also feel like my initial question doesn't really apply anymore and this thread has become muddled with my meanderings. Maybe I'll start a new thread and post everything correctly and in an organized manner from the start.
πŸ“ Reply
Topic:
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump