Ethan, Dan, Steve, John, i need some heads-up here....

[Eric_Desart]

Glenn,

I don't have that book. Hence can't have an opinion.
If you think based on the info you have that centered is better it's OK for me.
I doesn't fit my belly for now.

If that gives good descriptions about the stuff, Ill buy me one.
Does that book includes any comparative measurements which relates to the point I was discussing?

[gullfo]

Hi Eric, the appendix 1 is devoted to absorption methods and includes several other mechanisms as well as the hangers and compares across a variety of metrics. i think you will find good information there, but we all believe in the belly of Eric too!

[orangenumerik]

Hi Glenn,

I'll get a copy of that book for sure, there are just so many of them, that's just the info i needed to buy one. Thanks.

regards

[Eric_Desart]

Thanks Glenn,

You're a kind guy,
But you give a very general vague answer.
In a gentle, respectful, but indirect/suggestive manner you question my careful reply (Eric missed something).

I was discussing a very specific point, literally asked for.
I want to hear you say that based on the information you have, you advice to mount these hangers in the center between ceiling and floor.
Which was EXACTLY the point I was discussing.
What you do is diffusing my reply without putting anything as alternative.

Or can you please give some scan, quote or metrics from the part showing the answer for the discussed point.

The general fact that it describes absorption mechanisms, and shows related metrics is no answer.
I do understand absorption mechanisms (I specifically studied physical acoustics remember?), I also have books describing absorption mechanisms and teached engineers about them and acoustics in general.
This doesn't mean that it isn't interesting to me to read more and more and learn from it. I know, no matter how hard I try, I will die with much more questions than answers.

It's just because I didn't (and still don't) understand the metrics of hangers, that I searched as hell to find related stuff and only could come up with a university level study telling it's a paradox.
Does Newell solves this paradox?

This is the first time I tell this so explicit here ....
I'm always EXTREMELY careful about this because this calls for more study, but .......
It's just because I didn't understand the metrics of hangers that .....
As far I can tell from everything I can read on the net, I'm the ONLY guy who EVER really compared/measured hangers versus an alternative solution (thick wool on a cavity using the same space constraints and no, not based on THE 1/1 ratio believe/dogma/slogan).

These hangers were mounted by a master carpenter working for Eastlake audio itself, and he got all materials he asked for, applying the design as applied/intended by Eastlake Audio (can't be much closer to the source of the idea/principle).
This wasn't a scaled model as in that British study, but a real live studio application.
And while such hangers are good (but I still don't understand exactly how, when and why), the result was that I never applied them based on these costly and time consuming experiments.
And these results were discussed with Prof. Dr. Ir. G. Vermeir from the Department Acoustics - Catholic University of Leuven, in order to understand/interpret them.
But I do agree, I do not express explicit statements about them, without further study.
But my belly, while certainly fallible, is based on lots and lots of stuff.

Except for the empirical experiences, described often here (but not detailed studied or compared to whatever alternative), and results referred to by John (from his long and valuable experience), from the theoretical point of view I never saw anything convincing yet referred to in the forum.
Moreover, all theoretical references shown here until now (when explanation could be seen), more point to the lack of available insight and real study.
In fact John with the most real live related experience is very careful (which is a scientific attitude to be admired) in the why and how.
He, not just once said (free wording by me): "..... that's how they told me, and when I move them they ........

It are not rarely the ones with MUCH less experience and knowledge than John, who seem to have the final answers.
This doesn't refer specific to you Glenn, I know you're rather careful. In this case that careful that you in fact don't answer the specific question at hand.

There are designs here, the clear ceiling or back wall treatments and comparable, where I do believe them to be good.
But I also see them handled as some magic where a few are forced behind corner traps or whatever narrow spot and for me, giving me the feel of a questionable application.
It's just because I can't prove most of it, and just have my belly to go on, that I rarely intervene in such cases.

In this case however (the centered height), this is a clear principle being discussed and/or asked for.

[gullfo]

if the largest of the hangers are nearly floor to ceiling (and i believe that is size of hangers in the research in Newell's book - but not performed by him - a PhD thesis presented the research). then i would say centered between floor and ceiling.

Eric - since we're all aware of the shortage of detailed mathematic models and detailed research data, let me turn the question a bit and ask (gently): if you were building this corner trap, what would you use? is there a more cost effective method?

[scottmichal]

Would it make sense to put a few inches oh roxul or 703 at the openings into the area with the hangers. If we make that area a trap it seems like it would add an extra level of bass absorption since the sound waves would travel through the insulation, bounce around in the hanger cavity allowing them to do their magic along with more 703 or roxul lining the walls, then eventually exiting back through the insulation at the entrance. Or would that actually reduce the effectiveness of the hangers by absorbing the energy before it reaches the hangers.

[Soundman2020]

Would it make sense to put a few inches oh roxul or 703 at the openings into the area with the hangers.

Yes it does make sense. I often do that on the rear wall, in front of the hangers. It can indeed give you a boost in low frequency absorption.

- Stuart -