R/E/P Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: Bass Traps and Diffusers  (Read 3991 times)

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Bass Traps and Diffusers
« on: November 09, 2007, 07:37:55 AM »
It seemed it was not a good sign that my mixes (in the car) only sounded balanced after turning the bass almost all the way down and cranking the treble a bit.
So I had a friend evaluate them in his control room. 6 dB reduction at around 300 Hz(Q?)and a slight boost at 6K and up made everything so much better.
This morning I downloaded Ethan's ModeCalc and bingo....huge bump from 200-350. Gotta build some bass traps.
I'm thinking the top end could be from reflections, so strategically placed absorbtion and diffusion around the mix position? (RFZ?)
Or I could just slap an EQ across the 2-buss......

Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.

gullfo

  • Full Member
  • ***
  • Offline Offline
  • Posts: 133
Re: Bass Traps and Diffusers
« Reply #1 on: November 09, 2007, 11:37:11 AM »
bass traps definitely, and some 1" absorbers on your first reflection points plus maybe some on the rear wall to reduce the reflections from the back without making things dead...
Logged
Glenn Stanton

www.runnel.com/

Ethan Winer

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 571
Re: Bass Traps and Diffusers
« Reply #2 on: November 09, 2007, 02:55:23 PM »
Bill Urick wrote on Fri, 09 November 2007 07:37

This morning I downloaded Ethan's ModeCalc and bingo....huge bump from 200-350. Gotta build some bass traps.

ModeCalc is great for designing a new room, but it's no substitute for actually measuring what you have. Regardless, all rooms need as much bass trapping as possible, so definitely start there.

Quote:

Or I could just slap an EQ across the 2-buss

Please tell me you're kidding. Shocked

--Ethan
Logged

gullfo

  • Full Member
  • ***
  • Offline Offline
  • Posts: 133
Re: Bass Traps and Diffusers
« Reply #3 on: November 09, 2007, 03:22:19 PM »
EQ is still valid as the __final_step__ in getting everything as neutral as possible, its just that is a very small adjustment compared to the overall room treatment...
Logged
Glenn Stanton

www.runnel.com/

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Re: Bass Traps and Diffusers
« Reply #4 on: November 09, 2007, 08:56:12 PM »
Ethan Winer wrote on Fri, 09 November 2007 14:55

Bill Urick wrote on Fri, 09 November 2007 07:37

This morning I downloaded Ethan's ModeCalc and bingo....huge bump from 200-350. Gotta build some bass traps.

ModeCalc is great for designing a new room, but it's no substitute for actually measuring what you have. Regardless, all rooms need as much bass trapping as possible, so definitely start there.

Quote:

Or I could just slap an EQ across the 2-buss

Please tell me you're kidding. Shocked

--Ethan


Weeeeeeeeeeeeell.............

It would be a lot less trouble.....

But, yes.
Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.

J.F.Oros

  • Newbie
  • *
  • Offline Offline
  • Posts: 42
Re: Bass Traps and Diffusers
« Reply #5 on: November 11, 2007, 07:24:27 AM »
gullfo wrote on Fri, 09 November 2007 22:22

EQ is still valid as the __final_step__ in getting everything as neutral as possible

At least in the very low frequency range (under 60-70Hz) where passive acoustic treatment is much harder to properly do it ...
Logged
[ Flaviu Oros - acoustics engineer ]
[ JF Studio Design - Romania ]

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Re: Bass Traps and Diffusers
« Reply #6 on: November 11, 2007, 07:03:17 PM »
So.........

Anyone got a suggestion re what makes a good membrane?
For a bass trap?
Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.

gullfo

  • Full Member
  • ***
  • Offline Offline
  • Posts: 133
Re: Bass Traps and Diffusers
« Reply #7 on: November 12, 2007, 07:58:10 AM »
plywood, MDF, just about any material with an even density that can be easily worked with. a quick search should give you a bunch of sites with panel construction info and how to calculate the panel center frequency etc. one trick is to cut a 12"x12" piece of the material and weigh it so you know how dense it actually is. thicker/denser panels and deeper traps equal lower frequency.
Logged
Glenn Stanton

www.runnel.com/

franman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 580
Re: Bass Traps and Diffusers
« Reply #8 on: November 13, 2007, 08:00:28 PM »
gullfo wrote on Fri, 09 November 2007 11:37

bass traps definitely, and some 1" absorbers on your first reflection points plus maybe some on the rear wall to reduce the reflections from the back without making things dead...


I would suggest more like 3-4" minimum absorption at the first reflection points.. to affect comb filtering down to midrange... the 6K think is most likely a harmonic of something lower as the path length difference for 6K is quite short.
Logged
Francis Manzella - President, FM Design Ltd.
                 - Managing Director, Griffin Audio
fmdesign.com
griffinaudiousa.com

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Re: Bass Traps and Diffusers
« Reply #9 on: November 13, 2007, 10:47:31 PM »
Thanks all. After reading everything I could find re bass traps I'm looking at two 4' x 8' corner traps, 4" of 703 in the rear of the room, possibly with roll insulation behind them. Sound reasonable? Gotta deal with the bass first. Ethan seems to favor a more broad band approach. A wood membrane appears to be more frequency selective (as is my problem) but I'm not sure whether to try that first. Decisions, decisions.....
Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.

franman

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 580
Re: Bass Traps and Diffusers
« Reply #10 on: November 15, 2007, 12:10:11 AM »
Start with all the broadband stuff (corners and deep traps) you're describing. These will affect your specific problem frequencies as well, so afterwards you can decide if frequency specific traps (panels, resonators) are required. That's the ticket.   Cool
Logged
Francis Manzella - President, FM Design Ltd.
                 - Managing Director, Griffin Audio
fmdesign.com
griffinaudiousa.com

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Re: Bass Traps and Diffusers
« Reply #11 on: November 15, 2007, 07:10:58 AM »
Thanks Franman, that's the endorsement I was hoping for. If these don't do it I'll look at adding some of these:

http://www.ethanwiner.com/BTPlans.gif

but I hope the 4x8's take care of it....

Thanks to all for the input!
Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Re: Bass Traps and Diffusers
« Reply #12 on: November 20, 2007, 07:55:21 AM »
gullfo wrote on Fri, 09 November 2007 11:37

bass traps definitely, and some 1" absorbers on your first reflection points plus maybe some on the rear wall to reduce the reflections from the back without making things dead...


Re first reflection points....
The room is 12'x26'x10' Any problem with using 2" absorbers only, no diffusers, at 1'st reflection points?
Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.

gullfo

  • Full Member
  • ***
  • Offline Offline
  • Posts: 133
Re: Bass Traps and Diffusers
« Reply #13 on: November 20, 2007, 11:21:08 AM »
2" 703 3pcf works, otherwise as Fran suggested, 3-4" - you want something with a mid-absorption coefficient of > 0.9. I like 1" or 2" angled off the wall as pretty effective but it depends on the rest of the absorption in the room as well.

index.php/fa/6714/0/
Logged
Glenn Stanton

www.runnel.com/

Bill_Urick

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1626
Re: Bass Traps and Diffusers
« Reply #14 on: November 20, 2007, 04:56:21 PM »
Angled 703.
Seems like a good idea.
Thanks!
Logged
Good sense is, of all things among men, the most equally distributed; for everyone thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.
Pages: [1]   Go Up
« previous next »
 

Site Hosted By Ashdown Technologies, Inc.

Page created in 0.064 seconds with 19 queries.