New Posts New Posts RSS Feed - Phase response doesn't matter anymore ?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Welcome to the Graham Slee Audio Products Owners Forum

 

Open to all owners plus those contemplating the purchase of a Graham Slee HiFi System Components audio product and wishing to use this forum's loaner program: join here (Rules on posting can be found here)

This website along with trade marks Graham Slee and HiFi System Components are owned by Cadman Enterprises Ltd

Phase response doesn't matter anymore ?
 Post Reply Post Reply Page  12>
Author
  Topic Search Topic Search  Topic Options Topic Options
shamu144 View Drop Down
Regular
Regular


Joined: 02 Nov 2010
Status: Offline
Points: 64 		Post Options Post Options   Thanks (0) Thanks(0)   Quote shamu144 Quote  Post ReplyReply Direct Link To This Post Topic: Phase response doesn't matter anymore ?
    Posted: 07 Aug 2011 at 3:59pm

I stumbled across this wiki page related to audio system measurments which I found an interesting read for those of us who are not familiar with this technical language and allow to get a glimpse of meaningfull measurments for audio signals.

When considering analog signals, I notice that some measurments are fairly common and very often quoted by manufacturers, like the frequency response (FR) or total harmonic distorsion (THD).
 
However, phase response is almost never quoted in the technical literature of manufacturers... When digging a little further, I get the impression that this concept is actually a fundamental aspect in audio signal processing, and is used for characterizing the behaviour of a system in the time domain. Under certains asumptions, the phase response and the frequency response can be used to fully describe the "so-important" transient response of a system (as opposed to steady state). That was a fascinating learning for me.
 
Phase response or phase shift (expressed in degrees as a function of the frequency) is apparently as meaningfull in audio as the standard and much more common Frequency response. Problem is that there do not seem to be an agreement in the Audio community on how it affects the sound we listen, nor does it appear necessary to have a perfectly flat (0º) phase response to produce good sound. 
 
An interesting paper for us headphone geeks is the AES report by Lipsh*tz: On the Audibility of Midrange Phase Distorsion in Audio Systems, where they determine that the audibility of phase distorsion is in fact far greater with headphones than with loudspeakers !
 
Another thesis report reach similar conclusions when analyzing The Influence of Phase Distorsion in Sound Quality, and notice that especially speech reproduction through headphones is extremely sensitive to phase distorsion... They also note that training can easily increase the skills of the listener to detect it.
 
As headphone users, shouldn't we pay much more attention to proper phase response of our systems, and maybe not so much to frequency response (highly individual HRTF make almost imposible achieve a perfectly flat FR) ? How could we know this, without proper measurments published by manufacturers ?
 
Is this the key for a true musical listening experience ?


Edited by shamu144 - 07 Aug 2011 at 4:01pm
Back to Top
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Retired

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 16314 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 07 Aug 2011 at 7:06pm
Originally posted by shamu144 shamu144 wrote:

...shouldn't we pay much more attention to proper phase response of our systems...?


"Phase Integrity" anybody?

I've been hammering on about it since 1998!!!

Also see the graph on this page http://www.phonostagepreamp.com/reflexmcphonostagepreamp.htm

And what is Ultra-Linear about?

"We call this innovation Ultra-Linear because that was the tag used to describe the great performance of the best sounding valve amps that first made their appearance in the mid 1940's. These techniques vastly reduce the phase modulation distortion and linearity distortions that are hard for solid-state audio designers to perceive let alone measure."

shamu, it seems nobody is interested - the hyper's say my explanations are hype and the reviewers all have tin-ear. So in 2008 we decided to launch this owners club forum for the express reason of giving the truth an airing.
That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
Back to Top
Fatmangolf View Drop Down
Moderator Group
Moderator Group
Avatar

Joined: 23 Dec 2009
Location: Middlesbrough
Status: Offline
Points: 9695 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Fatmangolf Quote  Post ReplyReply Direct Link To This Post Posted: 07 Aug 2011 at 7:17pm
Thank heavens you did Graham! I have seen the term "linearity" used about in other forums but the phase distortion you have worked to minimise is making a real difference in my hi-fi.
Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
Back to Top
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Retired

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 16314 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 07 Aug 2011 at 7:30pm
PS:

Whilst my competitors studied selling techniques and how to make their first million I was studying this very subject and every product I've designed considers this important matter.



But the customer (and reviewer) will more often than not fall for the competitor's sales line...
That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
Back to Top
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Retired

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 16314 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 07 Aug 2011 at 7:36pm
PPS:

Here's some more work on phase and gain margin...



It makes the difference between a screamer (what tin-ear reviewers like best) and something really musical (what customers like best).
That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
Back to Top
Graham Slee View Drop Down
Admin Group
Admin Group
Avatar
Retired

Joined: 11 Jan 2008
Location: South Yorkshire
Status: Offline
Points: 16314 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Graham Slee Quote  Post ReplyReply Direct Link To This Post Posted: 07 Aug 2011 at 7:40pm
PPPS:

You can hear the difference with loudspeakers too!
That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
Back to Top
shamu144 View Drop Down
Regular
Regular


Joined: 02 Nov 2010
Status: Offline
Points: 64 		Post Options Post Options   Thanks (0) Thanks(0)   Quote shamu144 Quote  Post ReplyReply Direct Link To This Post Posted: 07 Aug 2011 at 11:28pm
Originally posted by Graham Slee Graham Slee wrote:

shamu, it seems nobody is interested - the hyper's say my explanations are hype and the reviewers all have tin-ear. So in 2008 we decided to launch this owners club forum for the express reason of giving the truth an airing.
 
Or maybe few of us know ! Back 8 months ago, I did not have the slightest idea what phase response meant (well, I still don't but at least I think I understand now the basic and how important it should be when designing).
 
It is this forum and of course my listening experience with the UL that has braught to my attention this new dimension of the music reproduction.
 
However, I feel we lack some standardized measurments in the audio industry for this critical notion of phase response that would allow us to compare in a meaningfull way different designs from different manufacturers. I am not saying this is easy, but as long as this is not provided, I fear marketing strategies will keep increasing their victims count.
 
PS: I also belong to this post "baby boomers" generation, and might explain my lack of awareness in those more technical aspects.


Edited by shamu144 - 07 Aug 2011 at 11:44pm
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.072 seconds.