QRD height question

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PDR

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QRD height question
« on: 2 Dec 2011, 10:24 pm »
I have a QRD that I would like to place on the wall behind my open baffle speakers.
Its 4' high and 7'-4.5" long.

My speakers are about 6' from the wall.....Question:

Should the height of the QRD be determined by my Tweeters?....
Should I center (height) it with them?
Center of the wall?

The speakers are GR V-1s.....shown on my avatar.

Thanks

srlaudio

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Re: QRD height question
« Reply #1 on: 17 Dec 2011, 04:35 am »
I would put them at 18" off the floor to the bottom of the diffuser, centered on the wall.  This is a good starting place, and experimentation is encouraged.....

InfernoSTi

Re: QRD height question
« Reply #2 on: 17 Dec 2011, 02:14 pm »
I have Allen's (SRLAudio) Prime 37 diffusor.  Getting it up off the floor makes a huge difference.  I started out with it between the speakers in front but have been using it on one side for first reflection treatment to "balance" my room better.  I have been extremely happy with the product.  Oh, and I'm using OB (Hawthorne Audio SSI Trios).

John

bpape

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Re: QRD height question
« Reply #3 on: 18 Dec 2011, 03:00 pm »
Agreed.  Get it up off the floor a bit.  The woofer rear wave (pending crossover frequency and the low cutoff of the diffuser) isn't going to be diffused anyway.

Bryan

PDR

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Re: QRD height question
« Reply #4 on: 19 Dec 2011, 09:27 pm »
Thanks for the responses.
I just havnt had time to raise it yet....too busy with X-mass.
This weekend I will raise it.....There is a outlet on the wall, so 18" will prob be about right.

Inferno......I was inspired by your thread, and built these myself.....its the DIY in me.

It replaces a poly diffuser that I built, so far even on the floor I like it. Its placed on the front wall between my speakers. About 7' behind them, I pulled the OBs out another ft.

They were made from styrofoam.....took about 7hrs to build....if they dont pan out in the long run, no lose, they were very cheap to build.










PDR

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Re: QRD height question
« Reply #5 on: 28 Dec 2011, 12:54 am »
Mounted the QRD today.
It works extremely well, better than the poly I had before.
Very happy with the dipoles, will try my arrays next and see
what happens.



 

Rob S.

Re: QRD height question
« Reply #6 on: 28 Dec 2011, 02:18 am »
Wow!  Nice looking diffusor!  Like the colors, I'd love to have done mine DIY but lack the skills,time,patience so I had Allen @ SRL Acoustics do it for me.
4th picture from the end of this album: http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1156

What depth did you go with for your build?

Rob S.

PDR

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Re: QRD height question
« Reply #7 on: 3 Jan 2012, 11:57 pm »
Hi Rob,

Sorry for the delay on getting back....The depth is 8"

Big Red Machine

Re: QRD height question
« Reply #8 on: 4 Jan 2012, 12:31 am »
When you need/want a high prime number, then DIY is pretty much the economical path:




PDR

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Re: QRD height question
« Reply #9 on: 4 Jan 2012, 01:15 am »
Was just admiring your work today BRM......nice job!
What did you use for coating your styro?....looks like a roll on of some sort.
DIY has been very good to me... 8)

Big Red Machine

Re: QRD height question
« Reply #10 on: 4 Jan 2012, 11:03 am »
I pre-painted the pieces with latex before cutting the smaller pieces on the table saw.  Then I only needed to touch up the edges before assembly.

InfernoSTi

Re: QRD height question
« Reply #11 on: 16 Jan 2012, 02:58 pm »
PDR,

I want to say "great job" on your project...wow, you made those look great!  How have you liked them raised and having lived with them for a while?

And thanks for the comment...that made my day when I saw it. I wish I had such excellent DIY skills as yourself.  I manage it but they never have that finished look!  :lol:

Well done, indeed!

John

Thanks for the responses.
I just havnt had time to raise it yet....too busy with X-mass.
This weekend I will raise it.....There is a outlet on the wall, so 18" will prob be about right.

Inferno......I was inspired by your thread, and built these myself.....its the DIY in me.

It replaces a poly diffuser that I built, so far even on the floor I like it. Its placed on the front wall between my speakers. About 7' behind them, I pulled the OBs out another ft.

They were made from styrofoam.....took about 7hrs to build....if they dont pan out in the long run, no lose, they were very cheap to build.








PDR

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Re: QRD height question
« Reply #12 on: 19 Jan 2012, 12:28 am »
John, I have come to really like this Diffuser and what it does for my room.

Its given me more height....although I think that may be because the poly I had was only 4' high....and depth to my soundstage...perhaps more width as well.
It has really focused the vocals and instruments...where they came from a general
direction before they are now pinpoint. Sounds that travel across or back and forth
are too.....you know exactly where everything is now.

Still havnt had time to try my arrays out with them, soon though.

I dont know if these changes are whats suppose to come with a QRD, but its what I am getting..... :D

Perry

InfernoSTi

Re: QRD height question
« Reply #13 on: 19 Jan 2012, 12:16 pm »
The added clarity is exactly what I experience with my Prime 37 diffusor, Perry.  I get more depth and a smoother sound stage, as well.

What seemed "clear" before was actually muddy by comparison...but there wasn't a way to hear that until you add the diffusor.  I spent about a month without it and then added it back in and the change was immediate and a real step up. 

I have mine on the side wall in the first reflection position.  My room is offset to that side so the speakers are about 12 feet from the left side wall and 3 feet from the right side wall.  I have it on the "near" side (right) and it balances the room nicely.  I have some absorber panels on the far side wall and it all works great.

I glad you really like the diffusor...I wish more folks would have the opportunity to hear them in their listening rooms.

John

Big Red Machine

Re: QRD height question
« Reply #14 on: 19 Jan 2012, 12:37 pm »
I like the painting scheme you used.  Classy. 

And I agree, until you try diffusion you never really know what it can do for you.  I was pondering the idea of building some for my ceiling instead of the hodge podge of brands I have up there now.