Sound Quality Vs. Measurements - Page 244 - 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 16th February 2012, 07:32 AM   #2431
diyAudio Member
 
Join Date: Jun 2010
Location: St. Petersburg
Quote:
Originally Posted by a.wayne View Post
Nor Canaduh ! ...............
Actually you can visit AirSpace museum in Washington DC and see Aggregat 4 not far from the Moon landing module. An excellent museum BTW.

NASA was leaded by a team of German engineers captured in Germany by US in 1945. The rest of German specialists were deported to USSR and did the same.

Basically both Soviet and US launch vehicle technology is a split off Werner Von Braun V2 (Werner Von Braun was a chief of NASA later on).

Also modern experts claims that if Germany will start manufacturing of Me-262 half a year earlier that would be Germany who celebrates the victory in WWII.

Sorry pal but you should watch this at least before saying NO

http://en.wikipedia.org/wiki/Space_Race_(TV_series)
  Reply With Quote
Old 16th February 2012, 07:53 AM   #2432
dvv is offline dvv  Serbia
diyAudio Member
 
Join Date: Sep 2004
Location: Belgrade, Serbia
In general support of what Thorsten spoke about, I'd like to mention just two cases I find very interesting and know first hand.

Many years ago, a German made power amplifier, from a company called LAS (Linear Audio Systems), landed on my table. I had no previous knowledge of this company. Anyway, the amp was made semi-old and semi-new school, the voltage amplifier consisting of a differential pair with a current mirror, followed by a cascode stage. Its open loop bandwidth was a whopping 5 kHz, and its overall NFB factor was around 60 dB. Total disaster! But, its output stage used four pairs of TI's BD 249/250 C, the European version of their TIP 35/36 C - but not a straight copy, the BD models had a moderate Ft of ">3 MHz", but their Ton time was just 1 uS and Toff was below 4,5 uS. Remeber, this was in 1980, when typical Ton and Toff times were at least twice that on even the best of them. 2x15,000 uF for both channels, rated at 100 V/uS.

Switch it on and be shocked. Contrary to all reason, that amp made some wonderful music come true. It worked way better than it had any right to.

Quite the opposite with another amp, by Pioneer, I forgot its model designation. Open loop response to over 40 kHz, moderate overall NFB, latest RET (Ring Emmitter Transistors) devices by Sanken, audiophile parts, the works, and it weighed in at over 40 lbs, no joke at all. Capacitors 2x12,000 uF per channel, dual mono, the works.

Switch it on and stay expecting something which will never come. Detailed, but cold and lifeless, no slam, bass lines subjectively say -2 dB below what they should be. Very much a cold shower in comparison with what one would expect from such a product.

So, even measured specs can not only fail to convey the truth, but can actually even be misleading, since that Pioneer measured better in just about every field in the book, and was made much more up to the current philosophy at the time. In both cases, THD and IM were below the 0.01% mark, both had damping factors well over 200:1 at 1 kHz into 8 Ohms (though both were rated at more than delivered), and so forth.

All of which only further convinces me that there are only two absolute certainties in life:
1. You will pay taxes, and
2. Nothing is as simple as it seems to be.
  Reply With Quote
Old 16th February 2012, 07:55 AM   #2433
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by suntechnik View Post
NASA was leaded by a team of German engineers captured in Germany by US in 1945. The rest of German specialists were deported to USSR and did the same.
Yup, post WW2 there where many instances when russian tech and american tech collided in combat or other areas and they where so closely matched, even in looks, that it surprised anyone who did not know that both sides where working with the same blueprints from Germany and the designs teams had origanted from a single team in Germany during WW2.

Quote:
Originally Posted by suntechnik View Post
Also modern experts claims that if Germany will start manufacturing of Me-262 half a year earlier that would be Germany who celebrates the victory in WWII.
I rather doubt that. Germany in WW2 had several major weak points in their military strategy and make-up of the military forces that proved the undoing and can be laid mostly directly at the feat of the beastly Austrian and his Austrian "Comrades" who dominated the Nazi Party.

The biggest issue was not having superior or "miracle" weapons (except the A-Bomb perhaps) in good time. Most of what Germany had in more conventional stuff was plenty good enough to stand up to anything fielded by the allies on a 1:1 basis. What was missing was enough fuel to operate them and enough raw materials to build enough of them.

For example, the lack of a heavy bomber force stopped Germany from doing to the russian and english war industry and air force infra structure early on what the Americans and British did to the german in the latter part of the war (at horrendous civilian casualties it may be added).

There where many other such areas where the political leadership of Germany at the time made perfectly disastrous decisions about allocation of funding for research and production.

Well, ancient history. But it illustrates that superior quality does not always trump superior quantity.

Ciao T
  Reply With Quote
Old 16th February 2012, 08:09 AM   #2434
dvv is offline dvv  Serbia
diyAudio Member
 
Join Date: Sep 2004
Location: Belgrade, Serbia
Quote:
Originally Posted by suntechnik View Post
Actually you can visit AirSpace museum in Washington DC and see Aggregat 4 not far from the Moon landing module. An excellent museum BTW.

NASA was leaded by a team of German engineers captured in Germany by US in 1945. The rest of German specialists were deported to USSR and did the same.

Basically both Soviet and US launch vehicle technology is a split off Werner Von Braun V2 (Werner Von Braun was a chief of NASA later on).

Also modern experts claims that if Germany will start manufacturing of Me-262 half a year earlier that would be Germany who celebrates the victory in WWII.

Sorry pal but you should watch this at least before saying NO

http://en.wikipedia.org/wiki/Space_Race_(TV_series)
I beg to disagree.

Having a new plane nobody can catch at that moment is a strong advantage, no doubt of it, and it would have dragged on that war for years yet, with untold additional victims.

However, the old military adage, dating back to Roman times, still holds true without exception: you will have only that territory which your soldiers' feet can tread.

Fast forward to our times, with technology undreamt of in WWII. The US and the West had Iraq under sanctions for years on end, but in the end, they had to send soldiers, people, to make anything happen. Same thing in Afghanistan. And what excatly did they achieve? Nothing, really, just more havoc and more civil war. Their soliders did NOT walk their entire territoty, which left plenty of space for the other side to hide and operate from.

The drones used today will no doubt evolve further, and while they can do significant damage, they will NOT win wars. They are much more of an assasination weapon than a war winning one.

Like it or not, it still comes down to living people.

Your post above is historically and factually quite true, and I'd just like to add one thing - just as what would become NASA took German scientists headed by Werner von Braun, so the OS which would become CIA took German espionage and counterespionage people to share their experiences in "fighting communism" (when it was well known that many of them hunted down Jews, Gypsies etc as well as native German opposition). Again, PEOPLE, not just records, models, etc.
  Reply With Quote
Old 16th February 2012, 08:32 AM   #2435
dvv is offline dvv  Serbia
diyAudio Member
 
Join Date: Sep 2004
Location: Belgrade, Serbia
Quote:
Originally Posted by ThorstenL View Post
...

Well, ancient history. But it illustrates that superior quality does not always trump superior quantity.

Ciao T
My dad had started studying mechanical engineering in 1940, a year before the old Yugoslavia was involved in WWII. Fast forwarding, in 1944, some serious Allied help was delivered to Tito's Partisan movement, by then over half a million men strong.

Dad was in the technical corps, charged with the duty of introducing new US made tanks to the battle brew. Those tanks were used for exactly 3 days before they were sent to be rear support and reserve, while the Russian T-34 was pushed to the forefront.

The differences were cruical. The US tank (I think but am not sure it was the Patton, but I could be wrong) was easily the more suprior machine in practically all aspects - it had heavier armament, it was way better armoured than the T-34 all around, it's comms equipment was the lates word, etc, etc. Unfortunately, it also had a Detroit petrol engine, which did about 1 mile per 1 gallon of fuel, so they had to drag their own fuel tanks on wheels behind them, since they were deployed on exceptionally mountainous terrain, and in a country torn up in war, petrol was very hard to come by. Unlike G. Patton, we did not have the US Air Force send 50 McDonnel-Douglas Dakotas to drop fule by parachute 150 miles into the enemy territory.

The Russian T-34 in comparisom, if it didn't have its cannon and machine guns, could have been considered as a child's toy. Comms equipment as rumentary as it could be made, any armour to speak of was mounted only on the front of the tank, and so forth. But, it had an outstanding Diesel engine which was a legend in the way it was tolerant to inferior fuel, just what the army needs in time of war. And it was a KISS principle device, it was concieved as excpetionally easy to make - and was made in astounding numbers, so much so that it literally flooded the battlefield. Had to, because the only way a T-34 could hurt a German Tiger tank was to clobber him from behind, right into the engine bay, and for that to happen, there had to be enough of them so the German crew simply could not evade them all.

Which proves Thorsten's point - yes, quality matters, but enough quantity will eventually swamp the quality because quality is harder to make and can't keep up the pace.

An old WWII time saying:

The British understood WW2 as a game of croquet - hit one ball through the gate here, another there, and you will evetually end up at the last gate.

The Americans understood WW2 as a game of American football - grab the ball and go for a touchdown, and damn the cost.

The Russians understood WW2 as a game of chess - sacrifice the pawn here to grab the queen there.

Only the Germans took WW2 seriously and that's why they lost it.
  Reply With Quote
Old 16th February 2012, 09:14 AM   #2436
diyAudio Member
 
Join Date: Jan 2007
abraxalito, ThorstenL,

Could you point me to any research/published work that backs up your view?
I find that usually people who "flirt" with the "subjectivists' side" often discard the objective approach altogether and make no effort in researching and backing up their "truth" any further.
Much like what they accuse their opponents of doing - but at least they have posted some data to back their modus operandi up.
It's all out there to prove wrong if you're up to the task. If you don't take that extra mile and just stick to your beliefs, working on your projects without providing any objective or at least structured evidence to justify your approach, it's not surprising people will get the impression you are a member of a cult building audio gear based on "beliefs".
It is engineering after all.

For example one can find boatloads of work on noise shaping and its usability.
I understand there are people who believe noise shaping is not actually as "harmless" as we're told and others who believe noise shaping is just noise.
Could you point me to any published, peer-reviewed work that invalidates previous work on noise shaping or at least provides some evidence of its "evils"?
__________________
"You have a hierarchy: a mathematician, a physicist (which is a failed mathematician), and an engineer (which is a failed physicist)." - Andrew Jones

Last edited by TheShaman; 16th February 2012 at 09:30 AM.
  Reply With Quote
Old 16th February 2012, 09:32 AM   #2437
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 103
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
I'm not sure where beliefs come into this. I listen to S-D type converters (AD1955, PCM1792) and find they don't sound like the real instrument when compared to a simple and dirt-cheap multibit DAC (TDA1545,3 for example). I know from reading people like Stanley Lipshitz that noise shaping has issues in regards to dither. I read the ESS datasheet and noise modulation is admitted to be a facet of that chip (a plot is shown of noise vs DC level), which is held up to be the best of the S-D incarnations. I don't think the issue of whether noise modulation exists is in dispute, what's disputed is whether its significantly audible. I'm making a leap of faith if you like - in attributing the qualitative differences in what I hear to this issue - its because I know of no other significant issue with the technology.

<edit> As regards to your remarks about absence of 'structured evidence to justify my approach' - why would you feel there's a need for me to provide such? The market is the final arbiter - if my approach sucks in terms of sound quality, I have no doubt the market will let me know by voting with its collective wallet.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin

Last edited by abraxalito; 16th February 2012 at 09:44 AM.
  Reply With Quote
Old 16th February 2012, 09:40 AM   #2438
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by TheShaman View Post
Could you point me to any research/published work that backs up your view?
I am neither interested, nor do I have the time to put together a complete list of references in support of all the many facets and aspects of my views, where they are backed by work of others (some is based on personal experience and evaluation).

If you ask more specifically with regards to a specific view, I can provide references.

If for example you needed some background on how much distortion speakers produce, I can give a specific reference or raft thereof.

If you ask regarding the available SNR of a recording microphone, I can give examples.

If you wonder where I may gotten my notions what levels of HD at what SPL's and and of what order are audible with music or pure tones I may again be able to oblige.

I do not automatically post references for things I note, because much of the work is both extensive, long standing and widely publicised (except by certain people who would rather that true evidence based approaches would go away so they can continue to peddle their ideas).

So for the life of I cannot see what excuse anyone, involved with in the topic of audio quality and how measurements relate, may make to be unaware of it (my dog ate my homework)?

Ciao T
  Reply With Quote
Old 16th February 2012, 10:17 AM   #2439
tvrgeek is offline tvrgeek  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Md
Quote:
Originally Posted by suntechnik View Post
Actually you can visit AirSpace museum in Washington DC and see Aggregat 4 not far from the Moon landing module. An excellent museum BTW.

NASA was leaded by a team of German engineers captured in Germany by US in 1945. The rest of German specialists were deported to USSR and did the same.

Basically both Soviet and US launch vehicle technology is a split off Werner Von Braun V2 (Werner Von Braun was a chief of NASA later on).

Also modern experts claims that if Germany will start manufacturing of Me-262 half a year earlier that would be Germany who celebrates the victory in WWII.

Sorry pal but you should watch this at least before saying NO

http://en.wikipedia.org/wiki/Space_Race_(TV_series)
Shameless local plug,
The Air and Space Museum on the mall in downtown DC is definitively worth a trip. Finally, they are getting more "stuff" to put on display to give all due credit. You can't see it in only a day. Plus, you have to have a day to drive west to the Dulles annex where the SR-71 and Shuttle sit. You can no longer tour the old warehouses at Garber. Let me tell you cool it is to walk up inches from the only flying saucer, ( Avero) and hundreds of items that will never make it on display. A wall full of giant propellers off blimps and dirgables, but no one knows which ones. Engines. There was one sitting there: inline 6, twin overhead cam, direct injection, twin ignition driven from the cams, twin turbos with intercoolers. Features that would make any new Euro sedan proud. 1926. They also have what is left of the Japanese clone of the ME192. Built from memory as we sunk the sub with the plans.
  Reply With Quote
Old 16th February 2012, 10:18 AM   #2440
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

One more note.

Quote:
Originally Posted by TheShaman View Post
For example one can find boatloads of work on noise shaping and its usability.
Yet what we cannot find easily are works that actually are evidence based comparing which noise shaping algorithms at the levels routinely deployed in ADC and DAC's are able to preserve a music signal without audible degradation.

The we are treated to is a PhD doing a bit handwaving, referencing the equal loudness curves and claiming noise-shaping with the inverse of this is "psycho-acoustically optimised".

Given the evidence of the actual evaluation of by far more gentle noise shaping algorithms used for CD-Production one would be very werary of the introduction of much more aggressive versions, whithout extensive testing...

Quote:
Originally Posted by TheShaman View Post
Could you point me to any published, peer-reviewed work that invalidates previous work on noise shaping or at least provides some evidence of its "evils"?
How about instead of asking me for evidence why noise shaping is "bad" you point me to any published, peer-reviewed work that validates previous work on noise shaping using rigorous and extensive listening testing (including sufficient positive and negative controls etc.) or at least provides some evidence of it being reliably inaudible?

Ciao T
  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 03:26 AM.


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