room

Did all of you audiophiles realise that the room will make a far more significant difference, which is indubitable ?


Think about the distortion of sound due to the room compared with the distortion of the signal due to a mere cable.

Lets discuss...

 

I agree

 

"ding -ding"

round one.....

 

if you analyze final frequency response of a system(phase and amplitude) you will find all system effect on the sound like per/power or speaker or cables differ from room effect on the sound. electronics effect is more on phase and linearity but room effect is delaying signal and suming them that it cause damage to the sound field.
i think spending 100,000$ on a system in a bad room will not give you the good sound.

 

Yep it's true. Still there are people who live and work in Knightsbridge yet own Ferraris.

 

I'm sure most of us did realise.....some of us will even have used room EQ systems such as TAG/Meridian/Tact etc.

 

Happy New Year (again). My new years resolution is not to fuel the flames of pointless cable debates, or room debates, or rack debates, or hifi gizmo debates.

Mind you, I've never managed to keep a new year resolution intact after the first month or so in the past.....

 

I wish I had known 30 years ago what I know now about room acoustics. It would have saved me a fortune. Whenever I had problems with the sound - usually booming bass - I always assumed that the kit was at fault and changed it for something else.

 

well no techno bear, there's not much that can be done about it either.

The size of the room is important but so is the shape.

you can't change that, and yes, alexs2, you can use eq, and you can use acoustic products, but they dont work.

 

Lol, now you are just trying to be a protagonist

 

I'm sure you know a little about rooms since you are studying sound engineering .

 

Hi,

I would point out that the various distortions are of very different nature. The problem is that the human auditory system works one way and measurement gear another.



The absence of a material difference according to single dimension measurements does not preclude the presence of an audible difference (unless you happen to be Douglas Self) nor does the presence of a large amount of "distortion" according to such a measurement (that is difference between source signal and output signal) neccesarily result in gross or even at all audible differences.

Untill we have a comprehensive working model of the human auditory system (which would imply our ability to make an artificial copy of any major part of it, in other words "near perfect" hearing prosthetics) we must accept uncertainties and the fact that the way of the 'scope is not allways that of the ear.

So, the bottom line is that untill we really understand what causes differences in "cable sound" (and I find most common theories somewhat insufficient) and how to measure these all these discussions are futile.

As a final one, do YOU actually realise that the Human Ear has > 30% THD (for a 200Hz Tone @ 92db) and narrowband frequency response variations exceeding +/-20db with an averaged response that varies wildely with level and frequency and barely manages +/-10db 60Hz-8KHz?

What is even the grossest distortion in electronic equipment and from room effects compared to that? Anyone who made a recording microphone THAT BAD would be kindly taken aside and shot quick and painlessly out of mercy.

Yet few would argue that just because the Ear is such a $hitty transducer distortion below 30% and Frequency response variations below 20db are inaudible.

Ciao T

 

I assume that means you've tried at least one of these systems,but then if you had,you wouldnt be saying something like that.

Properly set up,all of these,and especially the TAG system,do work extremely well in managing room modes and bass problems.

 

I have read about your system on the internet. Perhaps we could get together to have a chat and listen one day ? ?


regards,

johnny

 

Hi,

First, it is not a contradiction. By pointing out that what is measured not always (but sometimes) correlates well with what being heard I underscore the point of uncertainty.

Alas, my facts and figures come from standard works on the subject and are backed by a long list of references. If I have too much time some time soon I might dig them out. For now some I have handy:

The Level of Harmonics produced in the Ear by Order and SPL:



The "average" sensitivity of the Ear with frequency for a given SPL:

The question is rethorical. My point is that the Ear is not a linear microphone and that the "DSP" performed in the brain has great impact on resolution etc., as transducer the Ear is hopeless, in acoustical terms.

Measurements that make sense if we wish to present a microphone with a clear and undistorted signal do not make sure that we will present the ear/brain system with something it recognises as undistorted nor is there any close causal relation between what measures poor when attempting to present an undistorted signal to a microphone and what is percieved as distorted.

And that is a DIRECT AND CAUSAL result of the way in which the function of microphone, mike preamp and DAT recorder differ from the Ear/Brain system.

Sure, my door is general open to all. I'm in Edmonton, PM me.... Currently short of time, maybe February? We could make it a little ZG gettogether, I suspect Simon (Tenson) would come, maybe BBZ feels like dropping in?

Ciao T

 

thorsten,

I do not disagree that the ear is not linear in response.

but we are all taught that roughly, 20 to 20 khz is the range.

below this, we can ALL feel the sound.

Above this range, makes a difference , (whether it is direct or indirect), to what is heard WITHIN the range.

So I'm not sure what your point is, so please make it explicitly clear.

Will we each have a chance to sit down for a period of time(in the sweet spot) and listen to our own material ?

 

Hi,

A line drawn on a green table by comittee consensus.

MY POINT is simple.

Due to the nature of the human auditory stystem certain types and patterns of distortion (be it harmonic, IMD, FR et al) will be well masked and hence are inaudible even in large amounts while in other areas the human auditory system is capable of identifying very small signals (or small levels of certain types of distortion) even many db below a steady state or random noisefloor, which would make them rather difficult to find and analyse with traditional measurement equipment.

Hence all bets are completely off as to the effects of anything, as to how much the room effects can mask small changes to the signal that are of a completely different nature to the changes imposed by room effects and so on.

The best we can do is to empirically "sound out" the limits. I agree that this would ideally be done in competently implemented double blind tests which are set up to maximise sensitivity by carefull arrangements of systems, rooms and finally suitable selection of listeners. Sadly this rarely if ever happens, both because of practical difficulty to undertake such studies without significant funding to a suitable level of statistical power and reliability, but more often because those who promote and carry out the most (in)famous blind tests in audio have a clear and present agenda that has no relation to actually finding any truth, merley to produce specious, semi-scientific support for their own various thesis's.

Sure, gatherings at my place tend more towards Social than music, I must warn and there are limitations, right now no burned CD's, but real CD's in clean condition and LP's are welcome.

Maybe by the time we meet I will have sorted out the PC Playback Audio side to my satisfaction, in which case any format is fine.

Ciao T

 

The problem lies with the measurement metrics that we use not being sufficient to characterise all the qualities to which the human ear is senstive. Lab equipment IS sufficient to the task but the problem lies in defining what you are going to measure and how to interpret the results - typical for a nonlinear system. The idea that lab equipment is insufficient is a myth that arises out of confusion with the fact that the WAY we use and analyse using lab equipment is inadequate. This is compunded by the fact that our knowledge of the ears working and the associated process of perception is not perfect.

 

Hi,

Not quiet. A Human Radio Operator is able to tease out considerable amounts of "signal" that are burried under 20 - 40db of noise (excercises for battlefield radio operators simulating the post nuclear strike rise in static - been there, done that and got the T-Shirt), simple groups of spoken words and numbers (in military coding).

We have no "lab" or even military battlefield gear that is quite equal to the same task, in fact our most advanced comms gear with huge bandwidth over a fairly narrow bandwidth connections slow to a crawl once noise levels get anywhere near trigger levels, never mind 20db above trigger level.

So no, there are areas, especially in acoustic pattern recognition where nothing artificial is yet equal to the human auditory system (never mind animals with much more acute if less "general purpose" hearing than us humans).

Ciao T

 

40db of noise? I spent some working in both automatic speech recognition systems for fighter cockpits and also for V/UHF radio evaluations with added noise. Thats too much.

The problem is the mindset of applying simple linear spectral analysis for nonlinear systems. I am not talking about pattern recognition thats something else. A modern top of the range spectrum analyser has dynamic range and descrimination the ear could never match however the problem comes when you just apply to measure 2nd harmonic distortion! Analysis and pattern recognition are not the same thing. I dont argue that humans are better than machines at pattern recognition (even then sometimes only though its more common for sound) but this includes an aspect of perception as well as measurement and it is at the perception level that machines fall over. Which is another argument entirely and definately my "home turf" as opposed to audio engineering in which my knowledge is occasionally inadequate!