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DavidPiska
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Building a High End Listening Room – Full Story

I would like to share with you a series of articles focused on room acoustics.

4: Fine-tuning the Acoustics
https://www.rdacoustic.cz/en/blog/2020/05/15/building-a-high-end-listening-room-4-fine-tuning-acoustics/

3: QRD67H – Hybrid Diffuser
https://www.rdacoustic.cz/en/blog/2020/05/02/building-a-high-end-listening-room-3-qrd67h-hybrid-diffuser/

2: Construction
https://www.rdacoustic.cz/en/blog/2020/04/21/building-a-high-end-listening-room-2-construction/

1: Goals
https://www.rdacoustic.cz/en/blog/2020/03/17/building-a-high-end-listening-room-1-goals/

COmusicaddict
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Thanks.

Links appreciated!

geoffkait
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Not a big fan of foam or

Not a big fan of foam or ceiling treatments. Compresses the sound and makes it all phasey.

DavidPiska
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Not a big fan of foam or

Not a big fan of foam or ceiling treatments. Compresses the sound and makes it all phasey.

Hi, sorry for answering this late, but I'll do it anyway:

Why do you think ceiling treatment per say causes what you say it does?

Also, when you speak of "compressed sound", do you mean parts of the frequency spectrum disappearing? That could happen with too much damping, which foam is used for, but what we used are diffusers – if you take a closer look, most of the surface is diffusive, not absorptive. Soundproofing one's room too much can hardly be the goal. :) Standing waves/resonance frequencies/sound reflections have to be treated, but enough acoustic energy of course has to stay (both of which the diffuser that combines a layer of wood+foam is especially good at).

And finally, I don't know what you mean by "phasey" sound.

geoffkait
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The best way to proceed with

The best way to proceed with room acoustics is to first map out the entire room for sound pressure, which requires a sound pressure level SPL meter and a test tone generator and one or more test tone frequencies. Without a map you’ll be unable to find the treasure. All attempts to treat the room by trial and error are like trying to solve x equations in x + n unknowns.

When you have located standing waves, slap echos, sound pressure peaks, e.g., room corners, first reflection points then those acoustic anomalies can be treated with some appropriate acoustic device. I am not (rpt not) saying these are the only anomalies in the room, but they are the major acoustic type anomalies.

For every action there is an opposite reaction so room treatments can often have negative reactions, for example tube traps and diffusers must be located with care, a tube trap directly in the corner might not be the ideal locations. And like speakers tube traps can usually benefit from some damping. In addition, speaker position is critical in a given room and must be re-evaluated as the room treatment program progresses. Speaker location itself is an entire discussion and cannot be done Willy Nilly.

I scrupulously avoid treatments such as SOXEX foam as even a small amount in the room obviously hurts the sound. Don’t get me started on chairs and sofas in the room that contain foam. One should proceed with caution as it’s quite easy to over-commit to some concept or another. Don’t get trapped by self-fulfilling prophecies. I’m a big fan of resonators, like crystals for example, isolation, Helmholtz resonators and even some far fetched devices such as tiny little bowl resonators and Schumann frequency generators. and so much more. Heck, I’m even a fan of isolating all furniture in the room.

Geoff Kait
Machina Dynamica
Not Too Chicken to Change

DavidPiska
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Right. We could certainly

Right. We could certainly agree and disagree on many things. Bowls and such funny things aside, I would actually agree with most of what you say here. While we consider decay time the most important parameter, starting with that, standing waves, frequency response and so on and basing the treatment choices on those and not trial and error, and only then fine-tuning the room once that is done, all of that (and so why we chose to do what we did) is in the articles linked.

What I don't understand is what any of the knowledge/thoughts you placed in your reply has to do with my question (which was rather simple, as was your initial reply), or our room for that matter, except maybe that you don't like foam for "obvious reasons" (I don't know SOXEX in particular).

geoffkait
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Are you referring to Ceiling

Are you referring to Ceiling treatments, been there done that. Didn’t like the results. I would not say never though.

As for “funny little bowls” he who laughs last laughs best. :-)

One of the very worst sounding rooms I ever heard was one that had around $20,000 worth of room treatments. No air, no soundstage, no extension, no pleasure. :-(

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