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-   -   Reconfiguring the Bedroom System with Alpha 4A Panels (https://www.audioaficionado.org/showthread.php?t=45256)

jimtranr 03-01-2019 06:02 PM

Reconfiguring the Bedroom System with Alpha 4A Panels
 
In my earlier thread on GIK-treating my bedroom audio system I responded to robd2 that its almost wholly absorber configuration did not sound overdamped. But, having been infected long ago with incurable audiophilia curiosa, I couldn't help but wonder way down deep if I couldn't squeeze just a bit more "life" out of the audio presentation in the acoustically-challenged 13'x11'x7'8" room by replacing the existing traps with some of GIK's Alpha 4A diffusor/absorber panels.

So I ordered four 11.5"x45.5" and four 23"x45.5" Alpha 4As. That would give me enough, I thought, to allow me to experiment with various placement options to determine the "just right" configuration. (You see, Serge, you were right--the room is a lab, after all.) If any Alphas were left over after my listening evaluations, the "extras" would find a loving home in the living-dining-room system.

As the photos and diagram indicate, all eight Alphas ultimately remained in the bedroom.

https://www.audioaficionado.org/pict...pictureid=4944

https://www.audioaficionado.org/pict...pictureid=4945

https://www.audioaficionado.org/pict...pictureid=4937

You can see that the narrow Alphas straddle the room's three usable corners, though clearance issues precluded orienting them at a 45-degree angle. They're mounted using GIK-supplied sawtooth hangers and Home Depot-purchased L-hooks drilled into the respective walls (using a rudimentary ABC trig formula to calculate their locations). The door-mounted Alpha hangs via an exposed screw drilled into a DIY over-the-doortop fitting I cobbled together from scrap lumber.

The tops of the L-hook- and door-mounted Alphas project out farther than the bottoms. To render them "straight-firing" into the room, I inserted spongy packing foam behind the Alphas as shown below.

https://www.audioaficionado.org/pict...pictureid=4946

https://www.audioaficionado.org/pict...pictureid=4947

If you read the earlier thread, you may remember that I tried the scatter-plated 244s in both the first- and second-reflection-point positions--and wasn't impressed with what "scatter" brought to the listening table. At the time, I couldn't move the scatter-plated trap further back on the right side, because that would have interfered with access to the closet. I subsequently rearranged the location of the closet's contents so I could cover one of its folding doors without incurring a major inconvenience. That enabled me to locate the right-side Alpha 4A further back on that side "wall". As a consequence, none of the Alphas is closer to either ear than five feet-plus.

So what's the verdict?

"This is the best sound out of your systems I've ever heard. Whatever you spent on this, you did good, Jim."

Thus my wife’s evaluation after auditioning a variety of symphonic, choral, jazz, opera, solo vocal, and “big” film score program material for a couple of hours in the bedroom system's newly-revised acoustic environment. I agree with her assessment--except on one point. It's the Alpha 4As that "did good".

Put another way, my back-then response to robd2 was incorrect. What I hear now with the Alphas in place is what I'd term "greater stage presence" in recordings made with an eye (or should I say "ear"?) to capturing the "sound" of the performance venue and all the activity associated with it.

I don't mean just hall ambience, though it's clearly more abundant and "touchy-feely", with a beyond-the-front- (and in some cases, side-) wall reach that not only obliterates room boundaries but breathes a more than reasonable facsimile of fresh air. What's equally noticeable is improved vocal and instrumental articulation, whether with massed ensemble or unaccompanied soloist. The subtle, sometimes previously-masked innards of complex musical passages are more clearly discernible, and so too the subtleties of dynamic nuance. With a well-made recording, the listener winds up inhabiting a reach-in-and-touch three-dimensionality that exceeds holographic.

Turns out that getting "a bit more" life out of the system was aiming too low. Way too low.

Antonmb 03-02-2019 12:36 PM

Your wife is a saint.

jimtranr 03-02-2019 01:46 PM

Quote:

Originally Posted by Antonmb (Post 955662)
Your wife is a saint.

Amen to that, Tony.

In that vein, it's notable that she refers to the new configuration as "Jim's cathedral", saying that she was tempted to enter the first audition holding a lighted candle and wishing she had some incense close at hand. But while I know that, inwardly, she rolls her eyes at the room's new esthetic, she's glad that it relieves what was its previous wholly Stonehenge ambience.

Fortunately, she appreciates what the new configuration brings to the listening experience. And that's the way it has been for the nearly 38 years we've been together. So I count myself extremely lucky.

jimtranr 03-03-2019 09:05 PM

I thought it might be useful as a reference point to specify at least some of the program material auditioned in evaluating the "performance" of the Alpha 4A panels in the bedroom system as discerned from the nearfield listening position used separately by my wife and me. All of it was laptop-fed and consisted of everything from CD rips (16/44) to high-resolution PCM (24/88 through 24/352) and DSD 64 and128 downloads.

Pictured below is a representative, though by no means complete, sample of the auditioned material:

https://www.audioaficionado.org/pict...pictureid=4955

Adding the Alpha 4As' "scatter" to the room improved transparency noticeably, whether the source was the twin guitars of Carlos Barbosa-Lima and Sharon Isbin, the voices of Mirella Freni, Christa Ludwig, June Monheit, or Sarah Vaughan, the more-distinctly-layered choirs of the Turtle Creek Chorale, the cymbal brushstrokes of Johan Dielemans, or massed tuttis wrung out of the Boston Symphony or New York Philharmonic by, respectively, Andris Nelsons and Leonard Bernstein.

I'm ordinarily not into "gimmick" recordings, but I had to try something out, given the broader rear-of-the-room diffusion envelope afforded with all of the Alpha 4As in place. Back in the early 1970s, San Francisco Bay Area FM station KIOI (or "K101" as it was marketed by its owner, James Gabbert) combined on occasional weekend evenings with classical station KDFC (Wikipedia says KFMS, but that's wrong) to broadcast quadraphonic programs, with KIOI on the front channels, KDFC on the rear.

Having built a Heathkit Scheiber decoder, a second tuner (Dyna FM-3), and a second amp (Dyna SCA-35) as well as owning a spare set of speakers (AR-4x's), I hosted several neighborhood listening sessions in my then-Pacifica home to the combined broadcasts. One of the pieces broadcast at every session was the Mystic Moods Orchestra playing Maurice Jarre's title theme for "Grand Prix"--and it was backgrounded by Brad Miller-mic'd race cars (Formula 1s?) tearing around the track. The illusion of being surrounded by all that horsepower in quad was quite impressive.

I've gotten "close" with the two-channel version over the years (I think thanks to an out-of-phase mix on the stereo recording), but I wasn't prepared for how far behind my listening position the cars "go" with the Alpha 4As installed. I'm not suggesting that as a selling point, but simply to indicate how effectively they "open up" the room when positioned far enough behind the listener. (And, yes...the "saint" also appreciates hearing Brabham, Clark, Hill [both of 'em], Ginther, and the rest roar around what I now call Woodhenge.)

jimtranr 03-06-2019 06:07 PM

Height matters...
 
If you've looked at the photos of the left and right side "walls" (consisting essentially of windows that "begin" at almost chest height on one side and a folding-door closet on the other), you may have noticed that the tops of the Alpha 4As in those positions are lower than those of the first-reflection-point 244s.

That's because even though both types of panels are mounted on DIY 5"-tall platforms, the Alphas are 2.5" shorter than the 244s. To remedy that visual disparity--and to see whether elevating the Alphas would make a discernible difference in audible system "performance"--I rummaged around my basement workshop for scrap lumber and cobbled together some makeshift 4"-tall blocks to place atop the Alphas' risers.

Elevating the Alphas by that amount puts their tops about 12" above the plane of my ears when I'm seated at the prime listening location on the edge of the bed. To test that placement's efficacy, I played three very familiar orchestral tracks--Aaron Copland's "El Salon Mexico" (Bernstein, Sony/Columbia DSD128), Gustav Holst's "Fugal Overture" (Boult, Lyrita, 16/44 rip), and the fourth movement of Dmitri Shostakovich's 10th Symphony (Nelsons, DGG, 24/96--I've always felt that in the climax of this work the composer was asserting with shaking fist, "I outlived that S.O.B. Djugashvili, after all").

What a difference. In each instance, the recording venue's soundstage expanded in depth, breadth, and the palpability of that "fresh air" sensation I alluded to in my original post. Nothing subtle about the speakers' disappearing act here.

I should note that, to my ears, the sense of increased "liveness" does not render the presentation "bright" or "harsh". Far from it. The combination of diffusion and absorption embedded in the Alphas strikes the right balance in the bedroom system as now configured. It's notable, for example, that the string bass and bassoon--important elements in the Shosty 10th's final movement--"hit" the listener with gut-wrenching presence. And the winds and brass? I'm still shaking my head.

One thing left to do: Build permanent 9"-tall risers for the side-wall Alpha 4As. Maybe then I'll post photos. :D

kubla36 03-06-2019 11:24 PM

It doesn’t take long for me to remember to move my alphas in front of the TV. I’ll be reading, turn on some background music, and after a while notice how the stage seems a bit shallower and a little information missing. Sound panels up and it’s all better.

jimtranr 03-27-2019 03:54 PM

Quote:

Originally Posted by kubla36 (Post 956390)
It doesn’t take long for me to remember to move my alphas in front of the TV. I’ll be reading, turn on some background music, and after a while notice how the stage seems a bit shallower and a little information missing. Sound panels up and it’s all better.

Roger that, kubla.

One benefit continued listening has demonstrated is just how effectively the selective (in this instance, one might even argue "wholesale") addition of diffusion has made the Studio 20s--and with them, the wall and furniture boundaries--"disappear" with recordings not hard-panned to them in the mix. This in a space replete with SBIR horrors accentuated by the inability to move the speakers further out into the room due to normal-use foot-traffic patterns.

Now my wife gets jittery every time I train my eyes on the living-dining room system walls.

Puma Cat 08-10-2019 02:51 PM

I have to read this thread thoroughly as I have GIK Acousics products I need to set up as well. Right now, I only have 2 24" x 24" Alpha 4A panels, which I hung on the "front" (the one behind the speakers) yesterday. They really brought a notable improvement to focus and clarity of the presentation. I will be buying a few more, but I have to go in small steps. I installed the four 24 X 48" GIK Polyfusors when I first got them from Keith and they made the room notably over-damped.

Lots of good information here to go through, thanks, Jim!

Puma Cat 08-10-2019 08:27 PM

So...I read this set of posting by Jim with considerable interest.

In particular, his comment:

"I don't mean just hall ambience, though it's clearly more abundant and "touchy-feely", with a beyond-the-front- (and in some cases, side-) wall reach that not only obliterates room boundaries but breathes a more than reasonable facsimile of fresh air. What's equally noticeable is improved vocal and instrumental articulation, whether with massed ensemble or unaccompanied soloist. The subtle, sometimes previously-masked innards of complex musical passages are more clearly discernible, and so too the subtleties of dynamic nuance."

is what I noticed just putting two 24" X 24" panels up along the half-wall that is behind my audio rack and comprises my "front wall".

As mentioned above, I'll be getting some more of these, but they likely will be the 11" x 45" panels.

jimtranr 08-15-2019 09:11 PM

Quote:

Originally Posted by Puma Cat (Post 975706)
As mentioned above, I'll be getting some more of these, but they likely will be the 11" x 45" panels.

That will certainly give you placement flexibility and the opportunity to experiment with various configurations.


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