Unexpected project...Infinty IRS Beta

[tomlinmgt]

No I understood them as diffuser panels, I just was interested in knowing how you arrive at how many you need, is it based on the linear footage of the wall behind the speakers?

One of the diffuser panels I'm building placed behind each speaker would be effective and an additional one in the middle even better. But those who know a lot more about this stuff than me insist there is a synergy that develops when you array the panels, so that's the route I'm taking. I haven't yet decided on rear wall treatments. I'll try diffusion, absorption, and a mix of both and see what I think. That'll come after the Betas are up and running.

 

[musichal]

Am following this with interest. An aside - I'm still lovin' my Fortes, Michael, and am now having Rick custom-build an equipment cabinet in walnut to match. Hope to be posting pics in a couple weeks, or so.

 

[Ken Boyd]

To be honest I have not powered up any of my speakers other than my Sansui's in the past year. I don't think they would qualify as near field in any stretch of the imagination but they are quite small compared to the rest of my speakers, and they will go quite loud, on my Fisher.

 

[tomlinmgt]

Am following this with interest. An aside - I'm still lovin' my Fortes, Michael, and am now having Rick custom-build an equipment cabinet in walnut to match. Hope to be posting pics in a couple weeks, or so.

Thanks for checking in, Hal. Oh, I wouldn't think for a second your love for the Fortes would've faded a bit. Another set showed up here in the area last week....but at twice the price I gave for yours. They weren't as nice, either. Hell, they'd have to be NOS right out of the boxes to be nicer than yours.

I'm anxious to see Rick's walnut creation....ought to look fantastic flanked by the Fortes.

 

[Negotiableterms]

Yeah big speakers are a pain, I sometimes just think I should get a pair of near field monitors and simplify life.

I've been there for 10+ years and I am tired of it. Near field that is.

Well... there may be an answer to that problem: big nearfield speakers!

From The Stereo Times 2003 CES reporting:

"The 7-foot tall Nearfield Acoustics Pipe Dreams model 18 Reference Hemisphere ($49,000 depending on finish) played marvelously through the elegant VAC PHI 70 Ultriode Mono Amplifiers and PHI 2.0 Master Controller preamplifier through the model 18's. Which if you didn't notice, are composed of eighteen 4" woven carbon fiber midrange/woofers and thirty-six silk-dome tweeters in a line array. Crossed over at 65 Hz, al low-end energy was handled by four 18' subwoofers in two separate enclosures. The sound, as usual, whenever driven with Silversmith cables (my present favorites on the Talon's) was splendidly delicate, while detailed and explosive whenever the music demanded."

The set shown in the reports' CES pic became mine in 2004... so I may be a bit biased.

 

[tomlinmgt]

Well... there may be an answer to that problem: big nearfield speakers!

From The Stereo Times 2003 CES reporting:

"The 7-foot tall Nearfield Acoustics Pipe Dreams model 18 Reference Hemisphere ($49,000 depending on finish) played marvelously through the elegant VAC PHI 70 Ultriode Mono Amplifiers and PHI 2.0 Master Controller preamplifier through the model 18's. Which if you didn't notice, are composed of eighteen 4" woven carbon fiber midrange/woofers and thirty-six silk-dome tweeters in a line array. Crossed over at 65 Hz, al low-end energy was handled by four 18' subwoofers in two separate enclosures. The sound, as usual, whenever driven with Silversmith cables (my present favorites on the Talon's) was splendidly delicate, while detailed and explosive whenever the music demanded."

The set shown in the reports' CES pic became mine in 2004... so I may be a bit biased.

Oh hell, Pipe Dreams. How close can you actually sit to them, NT? How far to you prefer to sit from them?

 

[Negotiableterms]

Oh hell, Pipe Dreams. How close can you actually sit to them, NT? How far to you prefer to sit from them?

Depends on the room, of course, but mine are about 12' apart, and I'm about 12' from the center. Bigger might be better, but I've had them in smaller (8' apart), and they were great that way too.

 

[tomlinmgt]

So are you in the process of building QRD diffusers Michael?

Just finished 'em up yesterday. Have a look.....

http://www.audiokarma.org/forums/attachment.php?attachmentid=453549&d=1378397074

That was the second and last big hurdle I needed to clear to move the Beta project forward. Now I just need to get a little cosmetic work done on the fifth QRD (you can see the top of it in the background of the pic), get them all hung (projects for this weekend), clean up the second mid/hi panel and get the woofers soldered and installed back into the cabinets. Gettin close.

 

[EWizard]

Cool Michael!

 

[EWizard]

I'm wondering if any of those QRD panels would benefit me flanking the sides of my bookshelf, behind my listening position?

 

[jimreeves]

Now I just need to get a little cosmetic work done on the fifth QRD (you can see the top of it in the background of the pic), get them all hung (projects for this weekend), clean up the second mid/hi panel and get the woofers soldered and installed back into the cabinets. Gettin close.

Hurry up will ya!
The suspense is killing us! Well, maybe not us, it's killing me! Well, maybe just vicariously killing me...anyway, Hurry up!

 

[jimreeves]

Re; QRD panels and Ewizard's bookshelf got me thinking, what if you have tall bookshelves full of alternating skinny and fat books. Then you pull all the skinny books half way out, then alternately pull half the fat books a quarter way out and leave the rest of the fatties pushed in. Wouldn't that be a sorta-QRD??? :scratch2:

 

[EWizard]

Ya know Jim, I've had that same thought.
I've also had the thought that you could have QRD panels on the back wall of the bookshelves between the back and the books.
Hmmm.

 

[dc270]

Hey Michael-

I got plenty of time to help finish those if you like- just let me know- can barter time for toys!!!
DC

 

[musichal]

I might be willing to come and listen to 'em for you for free. Throw in a cheeseburger and coke and I'll write you a good, objective review. For steak on the grille you get a great, objective review.

 

[tomlinmgt]

Re; QRD panels and Ewizard's bookshelf got me thinking, what if you have tall bookshelves full of alternating skinny and fat books. Then you pull all the skinny books half way out, then alternately pull half the fat books a quarter way out and leave the rest of the fatties pushed in. Wouldn't that be a sorta-QRD??? :scratch2:

Alright, you've forced me into acoustics geek mode. First, understand the construction of a QRD (Quadratic Residue Diffuser) is carefully calculated to achieve proper, even diffusion of specific frequencies. My units are built to within 1/16" tolerance, for example, and I used software to develop the designs. Bookshelves with random arrangements of books will not diffuse....not in terms of the technical definition, that is. They will, however, scatter sonic content but not always in a desirable fashion. Speaking hypothetically, this may create a concentration of content in the 1500-2500 Hz range reflected right at the listening spot yet have content in the 900-1400 Hz range scattered in directions that don't include the listening spot. You can see how this might be a problem.

The general rule is tame reflections and echoes with absorption first and then implement proper, calculated diffusion devices.

Now I sound like a geek and a snob. Happy now? :grumpy:

 

[tomlinmgt]

I'm wondering if any of those QRD panels would benefit me flanking the sides of my bookshelf, behind my listening position?

Diffusion on the rear walls is generally beneficial and recommended so long a your sitting position isn't too close....with the design of the device determining what that minimum distance is.

 

[tomlinmgt]

I might be willing to come and listen to 'em for you for free. Throw in a cheeseburger and coke and I'll write you a good, objective review. For steak on the grille you get a great, objective review.

Oh, so that's why you didn't give a glowing, gushing review of my rig after you came down for a visit. Damn...won't make that mistake again.

 

[Gang-Twanger]

Diffusion on the rear walls is generally beneficial and recommended so long a your sitting position isn't too close....with the design of the device determining what that minimum distance is.

You mean the rear wall, as in BEHIND the listener?

 

[Ken Boyd]

I have no doubt that I would really enjoy listening to those, but to be honest as much as I enjoy this hobby, I have other hobbies as well. I live on an island surrounded by salt water lagoons, and the port out to the ocean is only a few miles from my house. So as much as those cost, I would prefer a nice offshore fishing boat as I enjoy going offshore. I had one stolen a while back with no insurance on it, so I have thought about getting another one just am a bit gun shy with the economy the way it is recently.

Besides those hardly look like downgrading or simplifying life.

Well... there may be an answer to that problem: big nearfield speakers!

From The Stereo Times 2003 CES reporting:

"The 7-foot tall Nearfield Acoustics Pipe Dreams model 18 Reference Hemisphere ($49,000 depending on finish) played marvelously through the elegant VAC PHI 70 Ultriode Mono Amplifiers and PHI 2.0 Master Controller preamplifier through the model 18's. Which if you didn't notice, are composed of eighteen 4" woven carbon fiber midrange/woofers and thirty-six silk-dome tweeters in a line array. Crossed over at 65 Hz, al low-end energy was handled by four 18' subwoofers in two separate enclosures. The sound, as usual, whenever driven with Silversmith cables (my present favorites on the Talon's) was splendidly delicate, while detailed and explosive whenever the music demanded."

The set shown in the reports' CES pic became mine in 2004... so I may be a bit biased.