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new room, worse response, wtf?
Old 21st June 2009
  #1
Gear Nut
 

new room, worse response, wtf?

So I just moved and was very excited when my wife let me use the big family room for the studio. I just set everything up and was very dissapointed with the response. The room is 13x30x8 (way bigger than the bedroom I was in in out last house) and I set up 38% in and mounted the 8 bass traps I have. The bass is very uneven. I used ARC in my last room ( I know it's not a cure all, but coupled with the room treatment I was pretty happy) and I was hoping to not have to use it in the new room. Based on what I was hearing, I ran ARC and sure enough I have a 10db peak around 150hz which ARC doesn't deal with very well. What gives? Why is the bass response worse in the much larger room and how do I fix it?

Thanks!
Old 22nd June 2009
  #2
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Bump-worthy..

I'm in a similar situation: moved the studio from a bedroom to much larger living room. Got more basstraps, moved speakers away from walls and corners. Followed all the tips (speakers centered & firing long ways, 38% rule, tweeters at ear level.)

All this and I am having more bass issues now than before. :(
Old 22nd June 2009
  #3
Gear Nut
 

Any chance your speakers are about 3' 9" (or 7'6") off the front wall?

What kind of bass traps do you have? Where are they in the room?
Old 22nd June 2009
  #4
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Speakers are 3' 4" (from wall to front of speaker).

I have 4 mini traps, 1 microtrap and 6 Gik 244's in corners, behind sub & over mix position.
Old 22nd June 2009
  #5
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andrebrito's Avatar
 

You always have bass issues no matter the size of the control room unless it is really big.

The good thing is that the ear's sensibility is weaker at lower frequencies and the larger the space the lower are the first axial modes. tje ones with the strong peaks in rectangular rooms.

You might also be dealing with SBIR as well.
Old 22nd June 2009
  #6
Gear Nut
 

Quote:
Originally Posted by Gohanto View Post
Any chance your speakers are about 3' 9" (or 7'6") off the front wall?

What kind of bass traps do you have? Where are they in the room?
Actually, with the listening position 38% from the front wall the speakers were about 7 1/2 feet from the wall. I ended up moving much closer to the front wall (the speakers are about 3-4 feet from the wall) and put all of my bass traps (8 GIK 244's) on the front wall. The response did get better, the 150ish peak went down from 10db to 5-6db and a dip below that almost went away but it's still not as good as I expected it to be. What's the significance of those measurements you listed? Do you have a better suggestion for speaker/bass trap position for a 30x12x8 room with 8 bass traps?

thanks
Old 22nd June 2009
  #7
Gear Nut
 

Quote:
Originally Posted by KPHayes View Post
Actually, with the listening position 38% from the front wall the speakers were about 7 1/2 feet from the wall. I ended up moving much closer to the front wall (the speakers are about 3-4 feet from the wall) and put all of my bass traps (8 GIK 244's) on the front wall. The response did get better, the 150ish peak went down from 10db to 5-6db and a dip below that almost went away but it's still not as good as I expected it to be. What's the significance of those measurements you listed? Do you have a better suggestion for speaker/bass trap position for a 30x12x8 room with 8 bass traps?

thanks
The 3' 9" and 7'6" (the later is just a multiple of 3'9") measurements are the distances from the front wall where 150Hz would double from the reflections. Multiples of the 3'9" distance may also create issues off the back wall as well.

So it's not a likely room mode issue (which deals with the general dimensions of the room, which is what 38% rule applies to) but the sound traveling backwards from the speaker hitting the front wall and then bounces back and overlaping with the original signal causing peaks and dips. The best way to eliminate this would be having traps (spaced off the wall appropriately) placed at the first reflection point for the speakers along the front wall and the wall directly behind the speaker. Hopefully that'll help if it's the key problem.
Old 22nd June 2009
  #8
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Schaap's Avatar
Did you put basstraps in the wall/ceilingcorner(s) behind your speakerposition?
Old 22nd June 2009
  #9
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Putting the 244's on the front wall dealt with the suspected SBIR issues which likely were coupling with other positional and modal issues. That said, I'm not sure that all 8 on the front wall is the best place to put them.

A larger room will simply shift modal issues lower in frequency. It won't get rid of them.

I'm also assuming that the room is not perfectly rectangular, has openings into other spaces, etc. which will impact room response. Any chance of a sketch of the space showing what we're dealing with here?

Realistically, without any EQ, if you can get the response in a residential room to be within +/-4, you're doing pretty well. Obviously we'd like to get better if possible. It's just going to take some experimentation and potentially more treatment.

Bryan
Old 22nd June 2009
  #10
Gear Nut
 

Quote:
Originally Posted by Gohanto View Post
The best way to eliminate this would be having traps (spaced off the wall appropriately) placed at the first reflection point for the speakers along the front wall and the wall directly behind the speaker. Hopefully that'll help if it's the key problem.
Cool. Just to make sure I'm clear, you're referring to placing bass traps on the front and rear walls using the 'mirror on the wall, put trap where you can see reflection of speaker' method, right?

As of now, I have bass traps in the wall/wall corners (floor to ceiling) of the front wall, one directly behind each speaker, and two horizontally on a 6 inch ledge halfway up the wall. I'll try moving some to the back wall. By properly spaced off the wall, I assume you mean 4 inches? Any reason to move my listening position at this point?

Thanks for the help, I appreciate it!
Old 22nd June 2009
  #11
Gear Guru
 
Glenn Kuras's Avatar
Hey,
Since you bought our product you are more then happy to drop us a email or give us a call. It is very common for people to move rooms and need our help again with set up. As Bryan said you may need to try a few things before you can get it just right.
Old 22nd June 2009
  #12
Gear Nut
 

Quote:
Originally Posted by Glenn Kuras View Post
Hey,
Since you bought our product you are more then happy to drop us a email or give us a call. It is very common for people to move rooms and need our help again with set up. As Bryan said you may need to try a few things before you can get it just right.
Thanks Glenn, I may take you up on that if I have some time, but most of my time spent working on this is after hours and the weekend.

As Bryan said, there's a little more to the room than I described. I've attached a poorly done paint picture from the top view. Some things I haven't mentioned - there's a 7 inch ledge on the front and left walls halfway up from the foundation, the back right corner opens up to the stairway upstairs. I keep the doors on the right wall closed. The green shows the location of my 8 bass traps on the front wall. Suggestions?
Attached Thumbnails
new room, worse response, wtf?-room.jpg  
Old 22nd June 2009
  #13
Lives for gear
 

Front wall and front corners are good. For the rear, I'd pair them side by side directly behind the mix position on the rear wall. Nulls coming off the back are very common. You can try it just leaning them against the wall on a couple of folding chairs to experiment.

Bryan
Old 22nd June 2009
  #14
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Are any of you guys actually listening to the rooms or just making graphs?
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