Sound Quality Vs. Measurements - Page 141 - diyAudio
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 25th January 2012, 07:46 PM   #1401
tvrgeek is offline tvrgeek  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Md
Re, post 1393
It would seem we don't know THE right way to build an amp, but we know SOME very good ones. Each has different tradeoffs, and what clues from an imperfect signal cause us to interpret what we hear as pleasing or correct are not uniform. So, different proponents and detractors who due to their personal perceptions, hold their views passionately.

Science fact is within a range of acceptable statistical deviation. It is not the yes or no we would like it to be. Is light a particle of a wave? The answer is a clear "it depends."

This site is a free and open public forum. It has many of us wallowing in our stupidity, insightful views from those with the real practical experience, and everyone else. Part of being educated is both recognizing the difference as well as respecting it.

Please, let the debates continue! Besides like one of the great Peanuts cartoons had Linus say "Some of those old wives were pretty sharp"
  Reply With Quote
Old 25th January 2012, 07:51 PM   #1402
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
Originally Posted by mr_push_pull View Post
I've read many papers on various aspects of psychoacoustics. most of the times, nothing is mentioned about: the subjects used (are they trained listeners? are they average listeners? are they young, old, proven to have good hearing etc?), used gear, listening room etc. also, short sound samples are often used (isolated piano, sax you get the idea), while things can largely change with real music...
Could you list some of these papers? The researchers with whom I'm familiar generally are quite explicit about these variables.
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 25th January 2012, 08:23 PM   #1403
diyAudio Member
 
Join Date: Mar 2004
Location: At the output stage
Send a message via Yahoo to mr_push_pull
Quote:
Originally Posted by tvrgeek View Post
Re, post 1393
It would seem we don't know THE right way to build an amp, but we know SOME very good ones. Each has different tradeoffs, and what clues from an imperfect signal cause us to interpret what we hear as pleasing or correct are not uniform. So, different proponents and detractors who due to their personal perceptions, hold their views passionately.
even personal preference can be measured. science can account for that "subjective" deviation of preference from mean. can't see any reason why it shouldn't.

Quote:
Originally Posted by tvrgeek View Post
Science fact is within a range of acceptable statistical deviation. It is not the yes or no we would like it to be. Is light a particle of a wave? The answer is a clear "it depends."
well, it would seem very ambiguous and hard to define. but at the same time I see lots of people that would apparently die defending their beliefs. kind of a contradiction.

Quote:
Originally Posted by tvrgeek View Post
This site is a free and open public forum. It has many of us wallowing in our stupidity, insightful views from those with the real practical experience, and everyone else. Part of being educated is both recognizing the difference as well as respecting it.
I've said that myself in the past. a forum is what it is and nothing more. but there are times when one simply can't ignore that there are some people obsessively repeating over and over and over and over the same things without even trying to care about scientific proof.

Quote:
Originally Posted by tvrgeek View Post
Please, let the debates continue! Besides like one of the great Peanuts cartoons had Linus say "Some of those old wives were pretty sharp"
yes, my signature reflects my current view on some of the discussions here.


Quote:
Originally Posted by SY View Post
Could you list some of these papers? The researchers with whom I'm familiar generally are quite explicit about these variables.
I can't quote exact names right now but if you insist I can search.
just yesterday I was reading this paper on the correlation of sensation of harshness/preciseness with spectral distribution. guess what, the only subject used was the writer himself. also I can't remember many papers where the used equipment was mentioned. for all I know, they may have been using Logitech speakers.


now on a more philosophical note. I know people that sold their expensive, new speakers and switched to speakers that were made in the early '90s. I can't think of many people that sold their current production cars to return to some '90s model, except for nostalgic reasons. same thing with TVs or whatever. audio doesn't seem to obey the same rules and that is for obvious reasons, IMO.
__________________
we all love a good ol' stereotype until it's against us
  Reply With Quote
Old 25th January 2012, 09:01 PM   #1404
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Quote:
Originally Posted by mr_push_pull View Post
I can't quote exact names right now but if you insist I can search.
just yesterday I was reading this paper on the correlation of sensation of harshness/preciseness with spectral distribution. guess what, the only subject used was the writer himself. also I can't remember many papers where the used equipment was mentioned. for all I know, they may have been using Logitech speakers.
A couple cites would be nice so that I can get an idea of what you're talking about. Thanks!
__________________
You might be screaming "No, no, no" and all they hear is "Who wants cake?" Let me tell you something: They all do. They all want cake.- Wilford Brimley
  Reply With Quote
Old 25th January 2012, 09:20 PM   #1405
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Quote:
Originally Posted by tvrgeek
It would seem we don't know THE right way to build an amp
I doubt if this exists. Is there A right way to build a bridge, or a car? All engineering is compromise. That is why I find it amusing when people talk about the 'ultimate' amp/DAC/speaker etc.

Quote:
Is light a particle of a wave? The answer is a clear "it depends."
Yes, it depends on what question you ask. If you ask "which slit did it go through?", the answer is "both; it is a wave". If you ask "where on the screen did it end up?", the answer is "here; it is a particle". Physicists have learnt to live with this. Others have not, so try to get round the results of experiments.
  Reply With Quote
Old 25th January 2012, 09:30 PM   #1406
wahab is offline wahab  Algeria
diyAudio Member
 
Join Date: Nov 2009
Location: algeria/france
If "it" is there , then it s a particle but if it s by there then it s a wave...
  Reply With Quote
Old 25th January 2012, 09:58 PM   #1407
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by mr_push_pull View Post
what needs to be studied (and for some reason isn't) is what makes a specific topology sound better.
It is exactly what I am doing the whole my life.
__________________
"Our youth [...] have bad manners, contempt for authority; they show disrespect for their elders, contradict their parents, [...] and tyrannize their teachers. -- Plato, 447-367 BCE
  Reply With Quote
Old 25th January 2012, 10:08 PM   #1408
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by a.wayne View Post
Ask before , so i will sneak it in again , why no Hybrids, seems it would be the best compromise between all topologies, so why not more Hybrids...?
You are banging again in wide open gates.

All my power amp and mic pre designs since I come back to audio design in 2006 combine tubes and semiconductors. Some exceptions are SS only designs, like condenser mike with no tubes, crossover, mixer, other toys... However, before that (in 70-80'th) I used SS only because I had belief that transistors are more convenient, and tubes are obsoleted. Now I firmly believe that tubes will never be obsoleted. They have advantages for analog audio applications, especially when properly assisted by semiconductors.

What is usually called "Hybrid", is some weird combination of bad tube preamp with no feedback, high output resistance, and bad SS output followers presenting non-linear load to that poor tube. I don't play such silly games, you may search for my Tower-III thread here, it is totally different approach. But the word "Hybrid" is discredited, unfortunately, so it is hard to convince people even to consider to check how well hybrid amp can sound, when properly cooked by talented chef.
__________________
"Our youth [...] have bad manners, contempt for authority; they show disrespect for their elders, contradict their parents, [...] and tyrannize their teachers. -- Plato, 447-367 BCE
  Reply With Quote
Old 25th January 2012, 10:37 PM   #1409
tvrgeek is offline tvrgeek  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Md
It would be fun to raise a pint or two with many on this page.

The gentleman from Digi-Key responded to my unpleasant letter about On-Semi. My suggestion was to take a look at his supply chain. I doubt someone is counterfitting a 7 cent transistor, but selling seconds at full price seems very likely. Either that, or On-Semi (Sanyo) builds garbage intentionally. Digi-Key is stand up. I wonder if On-Semi is.

Mr. PP, Guess you never have had the pleasure of driving an old Morgan or TVR. You drive a shoebox Chevy for nostalgia, you drive an old British roadster for the thrill. 135 in a 64 Plus-4 is far more adrenalin than any new car. Alas, my knees can't deal with a clutch anymore.

So we still don't know which objective measure correlates to some perceived deficiency. Thinking outside the box per say, what effect would result in playing with the resonance or Q between the amp output filter and the speaker? We add capacitance to cancel driver inductance, but is that a good thing? We add indictance to keep the amp happy with the capacitive load. But the speaker load is unknown to the amp designer, so how do we pick the best output filter? Could this be one of the reasons otherwise very good amps get different results on different speakers? Or is it just something to make ugly square waves in magazine reviews and has no effect on the sound? It is tough to design half a system and tweeters do some really nasty things, so I worry about the interaction.
  Reply With Quote
Old 25th January 2012, 11:08 PM   #1410
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Tvr, you are just naive. Look at the complete specs for the 2N2222, and learn and grow. Second, the POSITION that this part is used can be filled by just about 100 different parts without any trouble at all.
Your second-guessing WHY we add Zobel networks and series inductors is below 'sophomoric', we are fully understanding why we NEED to add these extra components, and we wish that we did not have to.
For the record, the REASON a difficult load looks so bad with a given amp sometimes, has mostly to do with DAMPING FACTOR, not Zobel networks, etc. However, I must say that ANY amp using over 2uH inductance is potentially problematic, like the Hafler 120 that you are fixing. Bad design! Even Bob Cordell would agree with me on this, (I think).

Last edited by john curl; 25th January 2012 at 11:36 PM.
  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
Quality Control differences = variations in sound quality? KT Class D 3 4th June 2014 12:02 AM
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
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 11:56 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