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-   -   And now for the far more problematic Bedroom System... (https://www.audioaficionado.org/showthread.php?t=38753)

robd2 10-08-2017 09:55 AM

This is a great real world case study Jim, thank you for sharing. I have a very unconventional room layout that I'm also embarking on a journey to acoustically treat. I'm going to try and document here as you did as this is super helpful.

Regarding your first reflection point panels, did you try the 244s with scatter plates in this position? Diffusion is still the biggest mystery to me, when to use and when not.

jimtranr 10-08-2017 04:26 PM

No, robd2, as indicated earlier in the thread, I'd tried the scatter-plated 244s at only the second reflection points. And thought full-range 244s in that position elicited "better" performance from the system.

However, I conducted that audition before finishing up the acoustic treatment with the DIY panels covering the jewel cases...and making a number of component changes (replacing the active preamp with a passive, upgrading the adapter connecting the Uptone Audio REGEN to my USB DAC, replacing the standard USB 3.0 cable connecting the music-source external drive to the laptop with a Wireworld Starlight, slipping Stillpoints UltraMinis under the laptop, DAC, and amp, and--as of this coming Tuesday--replacing my old Tara speaker cable with Blue Jeans/Belden 10-gauge).

Once the new speaker cable settles in, I'll give the scatter-plated 244s a go at the first reflection points and maybe again at the second reflection points to see what, if any, changes I hear. I don't know the precise auditioning timeline, as I'm now neck-deep in a murder mystery I started writing in July and am spending most of my time these days working on that.

If I hear any changes that I consider improvements with a repositioning of the scatter-plates at either reflection point, I'll post here.

Jim

jimtranr 03-27-2018 06:40 PM

A minor(?) addition...
 
If you've followed this thread and been subjected to the occasional photo and/or positioning diagram, you've probably noticed that with the bedroom door open there's effectively no right front corner to trap. Besides, placing a trap in that location could interfere with foot traffic in and out of the room.

But, being a self-styled audiophile with an amazingly forbearing spouse (though she's drawn a redline at putting up a "cloud" in there), I decided to see how placing a 12"x48" Monster filched from the living-dining-room system in that location would impact the audible performance of the bedroom rig. The door, after all, is veneer-faced hollow-core, which suggests to me no-no's like "reflection" and "sound board".

I first tried hanging the Monster on one of those felt-covered plastic doortop hooks you can find at Bed Bath & Beyond so its height would correspond to that of the front-wall 244s and center Monster array. Right away it was obvious that doing so extended the lateral soundstage, particularly on large-scale orchestral recordings (symphonies, concerti, ballet, and "big" film scores). It also improved front-to-back layering on recordings not perspective-flattened in the mixing process.

But how would aural performance fare if I simply planted the Monster on the floor, as shown in the photo below? Even better, as it turns out. The extended soundstage was there, all right. So, too, the layering, and an even more palpable presentation of intra-soundstage space, sustain, and decay. I won't recount the number of OMGs uttered while listening from one piece to the next.

End result: I'll order another trap so I can return the "loaner" to the living-dining-room system. What's nice about the 12"x48" trap is that it's portable enough to be moved without hassle into that location for serious listening and out at other times.

https://www.audioaficionado.org/pict...pictureid=4656

https://www.audioaficionado.org/pict...pictureid=4655

chessman 03-28-2018 03:48 AM

Hey Jim, does the murder mystery involve a wife killing an audiophile? :stirthepot::64714-slap::D

jimtranr 03-28-2018 12:40 PM

Quote:

Originally Posted by chessman (Post 908458)
Hey Jim, does the murder mystery involve a wife killing an audiophile? :stirthepot::64714-slap::D

ROTFL!

No, Randy, though that's a great idea for one. But, tolerant as she is, Mrs. T refers every now and then to the panels as "those things". And I'm sure she'll have something choice to say when the new Monster due to ship on Friday shows up at our door. :D

jimtranr 03-31-2018 06:37 PM

More than five months ago I indicated to robd that once I finished tweaking the bedroom audio system I'd give diffusion another shot at the first-reflection and then at the second reflection points, and further back, by placing scatter-plated 244s there.

Although the tweaking is not yet complete--I'm awaiting an Uptone LPS-1.2 power supply upgrade for my ISO REGEN--I've done the diffusion listening tests in the following order:

1. I borrowed a pair of scatter-plated 244s from my living-dining-room system (so I wouldn't have to remove similar panels from the bedroom's rear walls) to test their effect at the first reflection point;

2. I moved the borrowed S-P panels to the second-reflection point (and some points further back) and reinstalled standard 244s at the first-reflection point;

3. I returned the borrowed S-P panels to the living-dining-room system and placed 2'x2' SRL Acoustics polystyrene QRD diffusers atop the second-reflection-point four-foot-tall 244s;

4. I put the 244s down on their sides so the bottom of each SRL diffuser was parked two feet above the floor.

In each instance, my ears were at least five feet from the respective-side scatter plate or diffuser. I tried different listening positions (a tricky proposition atop a bed) from extreme nearfield to the apex of a roughly equilateral triangle based on the toed-in positions of my Paradigm Studio 20s. What I settled on as the "ideal" position put my ears just slightly forward of the side-to-side plane formed between the scattering/diffusion devices. I diagrammed the room layout three posts earlier in this thread.

For source material, I listened to rips and downloaded 16/44 tracks of digital remasters of analog-sourced Lyrita classical recordings engineered and pressed by Decca during the 1960's and 1970's. I selected those because I'm familiar with the performances (compositions by British composers William Alwyn, Arnold Bax, Gustav Holst, and E.J. Moeran) and the naturalness of the mostly-Kenneth Wilkinson-engineered recordings. My reasoning: If anomalies showed up in these recordings, the rest was inescapably forgetaboutit.

Conclusion: I've reverted to the original trap configuration diagrammed three posts below. In each instance where scatter or diffusion was employed at either the first- or second-reflection points, or points further back along the side walls, I heard peaky mids not unlike the squawks emanating from a horn-loaded midrange driver or two I played with way back (I mean way back) in the Dark Ages. I could discern no benefit (e.g., a sense or perception of increased spaciousness or "airiness") that would even begin to offset the audible downside.

So in this room, at least, the rear-wall scatter plates suffice.

robd2 03-31-2018 09:01 PM

Excellent writeup Jim, thanks for following through. Your documented "experiments" are very informative to those of us also trying to tune our rooms.

bigblue 04-01-2018 05:04 AM

Great to follow your thread Jim.
Did you ever contemplate the possibility to go with high end headphones instead if speakers. It could be an alternative if/when you reach the end of the line with regards to room treatment.

jimtranr 04-01-2018 01:43 PM

Quote:

Originally Posted by bigblue (Post 909072)
Great to follow your thread Jim.
Did you ever contemplate the possibility to go with high end headphones instead if speakers. It could be an alternative if/when you reach the end of the line with regards to room treatment.

Thanks, bigblue. I'm strictly a listening-to-speakers guy, so headphones aren't even a remote consideration at this point. I'm fortunate in having a spouse who doesn't mind if music streams out of the open-door bedroom--not infrequently at high levels--while she's elsewhere in the house, even when she's watching TV in the living room. (Sorry, guys, she doesn't have any sisters.)

As for "end of the line", I'm virtually there. A 2'x4' Monster is due here on Thursday and will replace the 1'x4' pair at front-wall center. I'll park one of those "skinny" Monsters at the door so I can send the loaner home to the living room.

The last trapping option I want to try is turning the second skinny Monster sideways and installing it above the center Monster (thereby creating a "T") to test what, if any, effect treating the wall-ceiling intersection at that location will have on perceived system performance. Once that's done, so am I.

jimtranr 04-04-2018 04:47 PM

While awaiting the arrival of the 2'x4' Monster...
 
to replace the two 1'x4' Monsters previously hung at front-wall center (location indicated by the bare picture hooks), I've hung one of those one-by-fours horizontally at the wall-ceiling intersection centered between the speakers. The other one-by-four now fronts the open bedroom door. Now this place is really beginning to look like Stonehenge.

https://www.audioaficionado.org/pict...pictureid=4660

Once I install the 2'x4' Monster (due here later this afternoon, a day early, wouldn't you know), I'll do listening tests and post my impressions. However, Mrs. hasn't seen this yet, so you may not hear from me.


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