Can I Build a 1D-QRD Without a Calculus Degree?

tubalicious · 13th December 2008

OK, I have tried to get a simple answer about how to build a 1D-QRD and continue to get complex mathematical equations that leave me scratching my head.

It seems like it would be pretty straight forward and sure it is, I just need someone to break it down to laymen's terms. I have a control room that is 21.5L X 16.5W X 7.5H.

I want to put a QRD on the rear wall this is currently fabric-covered rock wool. I have a bunch of nice wood left over from the studio construction I would like to use. It's already stained and varnished nicely and is 3/4" X 12" X 8'. I can rip it to 7" or whatever but is the exposed edge to thick at 3/4"? Secondly, the rear wall is 9.5 feet, is there not just a simple sequence I can apply to design this? I also dont know if I should make a QRD that fits the whole rear wall or if I should just do the center 6 feet or what? Does my tuning it to whatever deficiencies my room is prone to come into play too? I know, I know, allot of questions for just wanting a simple answer.

I can also take pictures if this would help.

Thank you.

audiovisceral · 13th December 2008

ya it's easy.

Acoustic Calculator 1.5

will show you the basic 7 or 11 well pattern. repeat as much as you like. qrd's sound great.

Ethan Winer · 13th December 2008

I can vouch for the Acoustic Calculator linked above. No math needed, just follow the dimensions the calculator gives you.

Quote:

Originally Posted by tubalicious

I also dont know if I should make a QRD that fits the whole rear wall or if I should just do the center 6 feet or what?

I'd cover the whole width, but just the 6 feet in the middle (vertically). This leaves room for bass traps above and below in the important wall-floor and wall-ceiling corners.

--Ethan

tubalicious · 14th December 2008

Quote:

Originally Posted by Ethan Winer

I can vouch for the Acoustic Calculator linked above. No math needed, just follow the dimensions the calculator gives you.

I'd cover the whole width, but just the 6 feet in the middle (vertically). This leaves room for bass traps above and below in the important wall-floor and wall-ceiling corners.

--Ethan

Cool. Thanks for the quick reply. The ceiling height is only 7.5 feet. 6 feet would only leave me 9" on the top and bottom for trapping. In this instance would the 4 feet or so in the middle (vertically) be more appropriate?

tubalicious · 14th December 2008

Quote:

Originally Posted by audiovisceral

ya it's easy.

Acoustic Calculator 1.5

will show you the basic 7 or 11 well pattern. repeat as much as you like. qrd's sound great.

Can you re-post or elaborate on the link? It is not going there.

Thanks-

-PJ

tubalicious · 14th December 2008

Also, while I have your ear (haha), for a room of this dimension, should I also do diffusion in the left and right sides of the listening position or absorption?

Ethan Winer · 14th December 2008

Quote:

Originally Posted by tubalicious

The ceiling height is only 7.5 feet. 6 feet would only leave me 9" on the top and bottom for trapping. In this instance would the 4 feet or so in the middle (vertically) be more appropriate?

Yes, four feet high is probably perfect with that ceiling height. A two-foot wide panel straddling a corner impinges about 20 inches in each direction. So 7.5 feet minus 40 inches (for traps above and below) leaves 50 inches.

--Ethan

tubalicious · 15th December 2008

Any more info on the correct link to that calculator?

Thanks.

BadJones · 15th December 2008

Could'nt open the link either. try opening the attachment, it's a pdf file for a diy diffuser.

eirikur · 15th December 2008

Quote:

Originally Posted by tubalicious

Any more info on the correct link to that calculator?

Thanks.

Try this:
mh-audio.nl - AcousticCalculator

tubalicious · 15th December 2008

Thanks guys. This has been a huge help. I appreciate it.

Glenn Kuras · 17th December 2008

Quote:

Originally Posted by BadJones

Could'nt open the link either. try opening the attachment, it's a pdf file for a diy diffuser.

I have been looking for this PDF for months. THANK YOU!!!!!!!!!!

tubalicious · 27th December 2008

The PDF that was provided is excellent but only shows one size with a 9" depth.. I have 12" X 8" finished wood and was hoping to rip them down the centre. How do I calculate the sequence and depths for a 6" frame and will 6" be sufficient? Also, the wall it will be affixed to is a 2" X 6" studded, rock wool filled and fabric covered. Will the space above and below absorb enough to be sufficient bass trapping?

Thanks.

13th December 2008	#1
tubalicious Gear Head Joined: Feb 2007 Location: Atlanta, GA Posts: 40 Thread Starter	Can I Build a 1D-QRD Without a Calculus Degree? OK, I have tried to get a simple answer about how to build a 1D-QRD and continue to get complex mathematical equations that leave me scratching my head. It seems like it would be pretty straight forward and sure it is, I just need someone to break it down to laymen's terms. I have a control room that is 21.5L X 16.5W X 7.5H. I want to put a QRD on the rear wall this is currently fabric-covered rock wool. I have a bunch of nice wood left over from the studio construction I would like to use. It's already stained and varnished nicely and is 3/4" X 12" X 8'. I can rip it to 7" or whatever but is the exposed edge to thick at 3/4"? Secondly, the rear wall is 9.5 feet, is there not just a simple sequence I can apply to design this? I also dont know if I should make a QRD that fits the whole rear wall or if I should just do the center 6 feet or what? Does my tuning it to whatever deficiencies my room is prone to come into play too? I know, I know, allot of questions for just wanting a simple answer. I can also take pictures if this would help. Thank you.

15th December 2008	#9
BadJones Lives for gear Joined: Feb 2007 Posts: 552	diffusers Could'nt open the link either. try opening the attachment, it's a pdf file for a diy diffuser.

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13th December 2008	#2
audiovisceral Lives for gear Joined: Apr 2006 Posts: 1,546	ya it's easy. Acoustic Calculator 1.5 will show you the basic 7 or 11 well pattern. repeat as much as you like. qrd's sound great.

14th December 2008	#6
tubalicious Gear Head Joined: Feb 2007 Location: Atlanta, GA Posts: 40 Thread Starter	Also, while I have your ear (haha), for a room of this dimension, should I also do diffusion in the left and right sides of the listening position or absorption?

27th December 2008	#13
tubalicious Gear Head Joined: Feb 2007 Location: Atlanta, GA Posts: 40 Thread Starter	The PDF that was provided is excellent but only shows one size with a 9" depth.. I have 12" X 8" finished wood and was hoping to rip them down the centre. How do I calculate the sequence and depths for a 6" frame and will 6" be sufficient? Also, the wall it will be affixed to is a 2" X 6" studded, rock wool filled and fabric covered. Will the space above and below absorb enough to be sufficient bass trapping? Thanks.