Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th January 2012, 03:10 PM   #681
M Gregg is offline M Gregg  United Kingdom
diyAudio Member
 
M Gregg's Avatar
 
Join Date: Jun 2010
Location: UK
Its realy difficult..

Of course the HIFI in another room is reality..with all the sonic distortions..
I guess the problem is we are trying to make one location sound like another..

Perhaps thats why the HIFI can't do this it has to be tuned to the room acoustics..If you move it it will sound out of "tune"..

We are back to the Bass & treble controls...
So if we make an amp or system flat and have zero distortion its flat with reference to what...

Regards
M. Gregg
__________________
What is the sound of one hand clapping?
  Reply With Quote
Old 9th January 2012, 03:16 PM   #682
M Gregg is offline M Gregg  United Kingdom
diyAudio Member
 
M Gregg's Avatar
 
Join Date: Jun 2010
Location: UK
Its perhaps this that is the difference,

The distortion is zero so its sterile...mixing with room acoustics..

If a whole system was zero distortion from source to speakers with a non reactive room we might get close..or would we...

Regards
M. Gregg
__________________
What is the sound of one hand clapping?
  Reply With Quote
Old 9th January 2012, 03:22 PM   #683
M Gregg is offline M Gregg  United Kingdom
diyAudio Member
 
M Gregg's Avatar
 
Join Date: Jun 2010
Location: UK
So final thought..

We need the correct distortions to fool us into thinking its reality and if its loud enough to overcome the room acoustic..then its realy only head phones..

Regards
M. Gregg
__________________
What is the sound of one hand clapping?
  Reply With Quote
Old 9th January 2012, 03:23 PM   #684
diyAudio Member
 
DBMandrake's Avatar
 
Join Date: Nov 2010
Location: Glasgow, UK
Quote:
Originally Posted by DF96 View Post
Comparison with TV also brings in another issue: given a free choice, some people opt for distortion. For example, many people set up a TV with colours which are brighter (e.g. more saturated) than reality. They then get used to this, so a correctly set up TV looks pale and bland to them.
Excellent point. The audio equivalent is deliberate manipulations of the frequency response as alluded to by ThorstenL. There is no denying that certain non-flat response curves can sound impressive, or "larger than life" so to speak, in various different ways, but I find that the sense of being impressed is only short lived.

Our brain knows what sounds normal and eventually over time it "rebells" against it, whether it be by listening fatigue, or by attempting to psycho-acoustically compensate for the error - eg learning the error through constant exposure to it across all music types, and then factoring it out - which is something I'm sure that happens with bass response peaks and dips caused by room modes, which we eventually don't notice nearly as much with time. If we move the speakers thus re-arranging the peaks and dips it then throws them into stark relief, until we get used to the new arrangement.

Prolonged exposure to music on speakers that are tonally unbalanced I find gradually shifts my sense of what sounds balanced. For example too much bass eventually sounds more balanced, which then makes you feel like the bass needs turning up again to reach the previous perceptual balance etc...and can cause a slippery slope effect.

On the other hand prolonged exposure to a tonally balanced system doesn't seem to have that effect, at least on me - my perception of balance doesn't shift much at all even after hours of listening. This whole shift of perception / acclimatisation thing that happens with our hearing is an excellent reason why even if we're judging subjective quality through listening we still need measurements as an anchor to stop us sliding down the slippery slope...

Frequency response is of particular interest when it comes to "deliberate errors that might or might not sound pleasing" because some flaws in audio quality are irreversible and cumulative (like distortion and noise, dynamic range compression, excessive room reflections etc) whilst frequency response errors can be corrected by complimentary errors elsewhere in the reproduction chain.

It could be that someone that prefers a certain small "tweak" to the frequency response is actually unwittingly correcting for a complementary error elsewhere in the chain, rather than genuinely liking a non-flat end-to-end response. Because of the circle of confusion and the amount of processing that goes on in most recordings its very hard to know for sure though.
__________________
- Simon

Last edited by DBMandrake; 9th January 2012 at 03:28 PM.
  Reply With Quote
Old 9th January 2012, 03:57 PM   #685
M Gregg is offline M Gregg  United Kingdom
diyAudio Member
 
M Gregg's Avatar
 
Join Date: Jun 2010
Location: UK
If room acoustics are the problem..

What are the frequencies required to Null room sound or what frequencies will over come room acoustics (I know you can't remove them).

How do you create a flat frequency response that will remove room "sound"..

Then again what is needed to fool the ear into the close to reality sound..

Distortion....Humm an open window with a lorry driving by....we can tolerate some distraction<<<is this why after a point distortion is not a problem..Then again the ticking clock comes to mind removed by the mind after a point so you only notice when it stops... As long as the distortion is constant..with no change can the mind remove it like the clock..

Regards
M. Gregg
__________________
What is the sound of one hand clapping?
  Reply With Quote
Old 9th January 2012, 04:21 PM   #686
diyAudio Member
 
Join Date: May 2010
Quote:
Originally Posted by Pano View Post
Pollsters do it every day.
And the results are accurate, plus or minus 5%, 19 times out of 20.

How would we expect an audio amp to perform if the max power THD spec were given as 20W p/ch @ 5% THD with an asterisk that noted we really mean 20W p/ch @ 0 to 10% THD except every 20th song, in which case it will be [some value] greater than 10% up and including 100%?

Or, alternately, a panel of listeners consistently gave the amp high marks but every 20th time the same group listened it induced nausea?
__________________
" ... Go back to the beginning of a technology before the priesthood was established; that was the time when people were communicating information, not proving why there needs to be Priests. This is why the old texts tend to be so good. ..."

Last edited by Johnny2Bad; 9th January 2012 at 04:27 PM.
  Reply With Quote
Old 9th January 2012, 04:32 PM   #687
M Gregg is offline M Gregg  United Kingdom
diyAudio Member
 
M Gregg's Avatar
 
Join Date: Jun 2010
Location: UK
One other analogy..
The aeroplane...do you design a plane and not wind tunnel test it..
Test the wings separate the fuselage and tail plain all made with different people with a different plane in mind...then bring it all together and hope it works..

If you only test each HIFI component on its own and bring them all together..They have got to be flat response to work any thing else forget it..<<measurement

So how do you tune the HIFI? (with mods) or adding components that shape the sound.. adding and removing distortions and of course selection of components..and what transports work best with....<<<wind tunnel test..

Regards
M. Gregg
__________________
What is the sound of one hand clapping?

Last edited by M Gregg; 9th January 2012 at 04:34 PM.
  Reply With Quote
Old 9th January 2012, 04:33 PM   #688
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Milliways
Blog Entries: 4
Quote:
Originally Posted by DBMandrake View Post
Pano, with his "Sound Quality Index" ?
Not I! Sorry, it probably read like that. Sound Quality Index was just my shorthand for relating what we can measure to what we perceive as quality sound. I don't think one number will do it, no way.
I would dearly love to see some suite of measurements that DO give us a good indication of sound quality. But I need to do a lot of thinking before I post any more nonsense.

My business is images and they are a lot easier to judge. Not without problems and subjective debates, tho - even there.
__________________
Take the Speaker Voltage Test!
  Reply With Quote
Old 9th January 2012, 04:43 PM   #689
diyAudio Member
 
Join Date: May 2010
Quote:
Originally Posted by M Gregg View Post
If room acoustics are the problem..

What are the frequencies required to Null room sound or what frequencies will over come room acoustics (I know you can't remove them).

How do you create a flat frequency response that will remove room "sound"..

Then again what is needed to fool the ear into the close to reality sound..

Distortion....Humm an open window with a lorry driving by....we can tolerate some distraction<<<is this why after a point distortion is not a problem..Then again the ticking clock comes to mind removed by the mind after a point so you only notice when it stops... As long as the distortion is constant..with no change can the mind remove it like the clock..

Regards
M. Gregg
Although the room can introduce aberrations that interfere with a good reproductive performance, it is the same aberration that would happen with live music in the same room. I don't feel these are problems that relate to the reproduction of recorded music vs a live performance, since a bad sounding room sounds bad regardless; you would not want to listen to your cousin singing and playing guitar in that room either, if overall quality of the sound was important, or if you were attempting to record the performance.

This is different from audio amplifiers (etc) where there may be an issue with the amplified performance that is absent from the live one, and the goal is to eliminate the issue with the amplifier.

Similarly, our brains smooth over many inputs ... otherwise merely sitting at the keyboard and typing this sentence would be impossible. Without this ability, is doubtful even the act of listening to a hifi would be possible at all. So, this is not only normal, it's necessary.

We don't expect the same fidelity from an office radio than we do from a hifi, and much of that is due to the fact we are deliberately listening to the hifi rather than allowing our brains to essentially ignore the details and giving us the smoothed over result only, as with the office radio. Indeed, if everyone actually critically listened to the radio, the purpose of being in the office ... get some work done ... would be the task that is smoothed over, done without thinking.

If the average office radio were all we wanted, there would be no hifi industry at all and the whole discussion would have no earthly use; an adequate modern office radio that serves as a background to the primary task of work is a done deal and needs no further refinement.

Although room problems and sensory distractions are an everyday fact of life, they are not reasons to say we've done all we can do with regard to hifi reproductive quality, nor are they excuses for failure to continue to seek improvement. That they are issues with overall reproductive quality is undeniable; that they are significant to the point where no further work on amplifier distortion is needed is giving them too much credit.

Since an amplifier can create distortions that no room could, we should be trying to eliminate (or find a metric to measure) those specifically. Maybe those that are left once that set is solved or determined, are benign and don't matter as much. It is in that sense the issues you raised have their value. For example, there are some who say flat frequency response is not so important compared to other forms of distortion; perhaps the typical room problem, which introduces alterations in flat response yet is not necessarily bothersome, is illustrative of why; it's a normal, natural issue we tolerate well.
__________________
" ... Go back to the beginning of a technology before the priesthood was established; that was the time when people were communicating information, not proving why there needs to be Priests. This is why the old texts tend to be so good. ..."

Last edited by Johnny2Bad; 9th January 2012 at 05:06 PM.
  Reply With Quote
Old 9th January 2012, 04:49 PM   #690
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Musicians here on the forum understand well that they would sound in different rooms differently. Like, in one hall they sound nice, in another like a cat's cry. Why should we expect the same real sound in different rooms? And is equipment guilty if in bathroom the orchestra sounds like an orchestra in bathroom?
__________________
If I disappear suddenly, that means I finally created a time machine and pushed wrong button that brought me to Stalin's Russia. In any experiment any result is the result. Even if it is negative.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sound Card for Measurements Marik Solid State 2 2nd January 2012 08:59 PM
Sound Card Recommendations (For Audio Measurements) dchisholm Equipment & Tools 5 16th July 2011 09:40 AM
How to protect sound card during amp measurements? okapi Everything Else 13 2nd September 2008 03:06 PM
Quality Control differences = variations in sound quality? KT Class D 0 14th November 2004 06:51 AM
Sound cards - test and measurements jackinnj Everything Else 2 5th July 2003 03:02 PM


New To Site? Need Help?

All times are GMT. The time now is 09:18 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2