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Talk but not walk?

Hi Guys

This isn't meant to start a fight, but it is important to on lookers. As a qualifier, I have my own audio forum where we report on audio issues as we empirically test them. It helps us short cut on theories and developing methods of listening. We have a wide range of systems and they are all over the world adding their experiences to the mix. Some are engineers, some are artist and others are audiophiles both new and old. One question I am almost always asked while I am visiting other forums, from some of my members and also members of the forum I am visiting is, why do so many HEA hobbyist talk theory without any, or very limited, empirical testing or experience?

I have been around empirical testing labs since I was a kid, and one thing that is certain is, you can always tell if someone is talking without walking. Right now on this forum there are easily 20 threads going on where folks are talking theory and there is absolutely no doubt to any of us who have actually done the testing needed, that the guy talking has never done the actual empirical testing themselves. I've seen this happen with HEA reviewers and designers and a ton of hobbyist. My question is this, why?

You would think that this hobby would be about listening and experience, so why are there so many myths created and why, in this hobby in particular, do people claim they know something without ever experimenting or being part of a team of empirical science folks. It's not that hard to setup a real empirical testing ground, so why don't we see this happen?

I'm not asking for peoples credentials, and I'm not asking to be trolled, I'm simply asking why talk and not walk? In many ways HEA is on pause while the rest of audio innovation is moving forward. I'm also not asking you guys to defend HEA, we've all heard it been there done it. What I'm asking is a very simple question in a hobby that is suppose to be based on "doing", why fake it?

thanks, be polite

Michael Green

www.michaelgreenaudio.net


michaelgreenaudio
glupson
7,842 posts
 
prof,

do not take it too personally. You could not win. It seems that I became a troll, too, despite fully in good faith trying to explain why people cannot afford trial and error approach on everything. In fact, many would agree that it would be foolish. I am only sorry that I never got my answer about laminar flow as advertised on the website. It is baffling me.
glupson
7,842 posts
 
Michael Green,

I just noticed your post and am glad I did not end up being a troll. I do think that both you and prof have taken your arguments too seriously. I tried to stay in the middle, focusing on more tangible things.
prof
3,491 posts
 
Hi glupson,

Certainly not taken personally!

I honestly think a thread like this can be, and to some degree has been, turned into something somewhat valuable. I think it’s a good thing to identify the types of posts that are "bad faith" style posts, including the follow up replies.

I think if someone has a problem with a specific person, argument or claim, he should be specific about it. At least supplying examples. Otherwise it’s just an excuse to lodge gripes without being challenged on them, and therefore not showing openness to the idea you are wrong, and letting someone make the case you are mistaken.

And that’s not to mention the undercurrent of self-advertising that puts a stink into the noses of many people reading such threads.

I certainly defend the right of high end audio salesmen and manufacturers to post here, as they can contribute valuable information. (Geoff even contributed to one of my threads asking about turntable isolation, and I appreciated that!)

But I don’t think it should be at the price of those people always going unchallenged, if they are making critiques, gripes or bad-faith posts, and disguising advertising for their own web sites or products as dialogues about something else.

(And I’ve had people telling me I’ve given voice to their own feelings about this thread, so I'm comfortable that it wasn't "just myself" that I was arguing for).
glupson
7,842 posts
 
prof,

I kind of enjoyed this thread. Probably due to its bizarre turns. There were inexplicable characters, weird responses ("your adult diapers are elastic", or something to that effect), some concise and sharp observations, strange non-questions, a few topics completely unrelated to the original one floating around at random, a little bit of basic physics ("what is sound"), some pointers to other websites, one potentially interesting link on youtube (even if it was me who posted it), and food for my own thoughts rising from all the jungle I just mentioned. It was all quite entertaining. I learned, prompted by the thread but not in it, about some design features of airplanes, paint quality issues, how drums get tuned, botany (Nevada trees), CD-making process, dynamic ranges of albums I have, and a few more things. I have to give Michael Green credit and thanks for that. Had I started a thread, it would have died after a post or two. As this is supposed to be "hobby" website, I consider coming here "waste of time" or "entertainment" so I will have to admit that it served the purpose. All along, while following discussions on audiophile website Audiogon, I sat in silence or, at best, listened to Internet radio on $50 Bluetooth speaker. Not that I did not need room tuning, I probably would not have been considered worthy of logging in. Life is good. Just do not take it too seriously. I am sorry you got so upset.
geoffkait's avatar
geoffkait
23,365 posts
 
Turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, which tend to produce chaotic eddies, vortices and other flow instabilities.

The Reynolds number Re is defined as,

Re = fluid density x fluid velocity x characteristic linear dimension / dynamic viscosity of the fluid

where:

ρ is the density of the fluid (SI units: kg/m3)
u is the velocity of the fluid with respect to the object (m/s)
L is a characteristic linear dimension (m)
μ is the dynamic viscosity of the fluid (Pa·s or N·s/m2 or kg/m·s)
ν is the kinematic viscosity of the fluid (m2/s).

Reynolds number is proportional to the velocity of the fluid (air) which is rather low in a listening room, so Reynolds number will be relatively low. I don’t recall my pants legs flapping in the breeze whilst listening. It’s not exactly a wind tunnel. So turbulent flow is very unlikely or perhaps impossible. This is not to say there might be some advantage sonically to “organizing” laminar flow using shutters. Remember organizing laminar flow doesn’t mean there has to be turbulent flow or that turbulent flow is prevented.

I personally would have to experiment with the shutters to see what happens sonically. The viscosity of the air in a given room will be fairly constant except in the case of bowls of ice cold water, one or two or three or more, that I mentioned, in which case the viscosity and thus the Reynolds number will be different lower in the room than higher up. Reynolds number is mostly a function of temperature. And the speed of sound is slower in cold air than warm air. Therefore the part of the acoustic wave higher up in the room will be faster than lower down so that the wave will bend over and down toward the listener position. He will hear more of the sound, especially the treble, including ambient information. But because of the speed of sound issue not really Reynolds number.
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