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Testing audiophile claims and myths - Page 160

post #2386 of 3125
Quote:
Originally Posted by EthanWiner View Post


How is that different from reversing the polarity after the fact during playback?
Why do you believe this? Do you have any Wave files or FFT graphs or oscilloscope images that show PCM can't capture transients whose rise times equate to 20 KHz?

Again, I look forward to hearing one or two files you post that sound different when the polarity is reversed.

--Ethan

It is no different, whenever is the polarity inverted in the absolute sense.

 

It can be practically inverted many times in either the recording and/or reproducing chain; as long as the listener is presented with the correct absolute polarity, it is OK.

This is done because sometimes various electrical circuits that do offer other advantages ( lower noise...) are used despite being absolute polarity inverting. 

 

From decades of experience listening to phono cartridges/records it clearly emerged that reasonably flat response well past 20 kHz is required - it produces FAR more conviencing soundstage with recordings that did capture it. DSD128 is the first digital format capable of usable resolution to record the performance of phono cartridges on the most acid test, the square wave response. Any PCM up to 192/24 will distort the fine high frequency/time detail of the better cartridges to the point it can not no longer be distinguishable between two very similar cartridges/ styli. I will be publishing these photos from ANALOG display ( digital storage in Tektronix scope basically giulty of the same as PCM - it IS PCM !!! ) in Turntable Setup  thread

http://www.head-fi.org/t/613136/turntable-setup-questions-thread-dont-start-a-new-thread-ask-your-question-here

as a part of the forthcoming posts on phono cartridge electrical loading. There will be plenty of those - please allow some time, as the whole process will take quite some time and I do not want readers to jump to the wrong conclusion by looking at the very first picture pulled out of context.

 

The differences among different phono cartridge designs will be presented, along with VERY SHORT music samples( because of copyright reasons ) in DSD128. For the correct impression, native DSD128 playback is mandatory. I will also give 48/24 PCM version of the same short DSD128 clips for those without native DSD playback capability - but these can not tell the true story to the full. 

 

Please note that I consider DSD128 the very first usable digital audio format - like the Yugo was the lowest quality usable car. ( And what little Yugos did hit the USA shores, were spiffed up fully loaded models, unless more bare bones models available in what used to be Yugoslavia ).


Edited by analogsurviver - 3/3/14 at 3:55am
post #2387 of 3125

To those interested in comparing the PCM vs DSD, Channel Classics is offering free downloads of samples

http://www.channelclassics.com/try-it-now

in PCM as FLACs 44.1/ 96/192 kHz and DSD64 ( and ocassionally DSD 5 channel ) - including the front page and booklet . 

 

You can use Korg Audiogate software not only to convert from DSD to PCM (and vice versa, if required ) - but to use it as a player.

http://www.korguser.net/audiogate/en/download.html

With rather recently added High Quality as opposed to initially offered Light Load option , it became a truly superb sounding player on PC platform - I *guess* its Mac version is no worse. Same DSD file played by latest versions of Korg Audiogate do sound better than say DFF plugin for the latest Foobar 2000.  Both will convert to PCM - for full DSD quality, DSD DAC is required.

 

As full Audiogate is limited by the need to own a Korg MR series recorder or using Tweeter account for the authorization, there is now only player available for free : http://www.korg.com/us/news/2014/0203/

 

P.S: Sorry - just read authorization/activation by Tweeter acount is no longer supported. Player without using Korg MR series product will also perform in Light Load mode only - giving equal sonics as Foobar 2000. 


Edited by analogsurviver - 3/3/14 at 4:35am
post #2388 of 3125
Quote:
Originally Posted by analogsurviver View Post
 

Differences that big do not require blind A/B testing

 

Are you talking about a big difference when you say you could hear a difference between -90dB and -100dB crosstalk? That was the comparison that I was asking about.

 

Expectation bias affects everyone. But it's much more likely in a person who has their ego invested in hearing things other people can't (i.e.: audiophiles) than in regular people. I would say that blind testing is probably more important for you and I than an average person. Especially since being honest and accurate about what we hear is more important to us.

post #2389 of 3125
Quote:
Originally Posted by analogsurviver View Post
 

From decades of experience listening to phono cartridges/records it clearly emerged that reasonably flat response well past 20 kHz is required - it produces FAR more conviencing soundstage with recordings that did capture it.

 

People who do audio restoration of older recordings have a psychoacoustic trick to prevent recordings with limited high frequency information from sounding muffled. They introduce a little bed of low level, high frequency hiss. The ears hear the hiss and don't miss the lack of high end as much. A severely band limited 78 sounds a lot better with a bed of hiss than clean.

 

That's what is going on with your phono cartridge. The LP itself probably has little or no actual signal above 16kHz or so. But a cartridge that reproduces the surface noise in the upper frequencies tricks your ear into thinking it's hearing frequencies that aren't really there. All of it is probably in the range of 16kHz or lower. A cartridge rated to 20kHz probably starts rolling off the high end well below that limit.


Edited by bigshot - 3/3/14 at 11:05am
post #2390 of 3125
Quote:
Originally Posted by analogsurviver View Post
 

It is no different, whenever is the polarity inverted in the absolute sense. It can be practically inverted many times in either the recording and/or reproducing chain; as long as the listener is presented with the correct absolute polarity, it is OK.

 

What happened to the sample of the trumpet that you said sounded clearly different with reversed polarity than correct? Are you still going to post that for us to hear? I'd be very interested to hear that because I've never been able to hear the difference between different absolute polarities before.

post #2391 of 3125
Quote:
Originally Posted by analogsurviver View Post

From decades of experience listening to phono cartridges/records it clearly emerged that reasonably flat response well past 20 kHz is required - it produces FAR more conviencing soundstage with recordings that did capture it.

Ah, the old anecdotal evidence. Do this test again in a controlled fashion, and blind, and you'll find that frequencies higher than people can hear have no effect at all on the sound. The notion that ultrasonic frequencies must be captured and reproduced is the hold grail of audiophoolery. If someone could prove this they'd be famous! Alas, although people have tried countless times, no credible evidence has ever emerged that ultrasonics are audible directly, or indirectly as improved "imaging" etc.

As for phonographs and phono cartridges, any potential "benefit" one might wish was true is swamped out by their high levels of distortion and background noise, and wow timing errors literally 1,000 times greater than any digital jitter.

--Ethan
post #2392 of 3125
Quote:
Originally Posted by analogsurviver View Post
 

To those interested in comparing the PCM vs DSD, Channel Classics is offering free downloads of samples

http://www.channelclassics.com/try-it-now

in PCM as FLACs 44.1/ 96/192 kHz and DSD64 ( and ocassionally DSD 5 channel ) - including the front page and booklet . 

 

You can use Korg Audiogate software not only to convert from DSD to PCM (and vice versa, if required ) - but to use it as a player.

http://www.korguser.net/audiogate/en/download.html

With rather recently added High Quality as opposed to initially offered Light Load option , it became a truly superb sounding player on PC platform - I *guess* its Mac version is no worse. Same DSD file played by latest versions of Korg Audiogate do sound better than say DFF plugin for the latest Foobar 2000.  Both will convert to PCM - for full DSD quality, DSD DAC is required.

 

As full Audiogate is limited by the need to own a Korg MR series recorder or using Tweeter account for the authorization, there is now only player available for free : http://www.korg.com/us/news/2014/0203/

 

P.S: Sorry - just read authorization/activation by Tweeter acount is no longer supported. Player without using Korg MR series product will also perform in Light Load mode only - giving equal sonics as Foobar 2000. 

 

well colour me entertained.  i downloaded the files just for fun (i don't have a DSD DAC, but several different transcoding softwares).

 

the results were not what i expected.  i transcoded the DSD to PCM 24/192 using JRiver, i wish i had a DSD DAC but i'll wait until it actually has music to get :)  everything was played through the modi (and therefore downsampled to 24/96)

 

192 v. 44 PCM: 10/10

192 v. 96 PCM: 6/10

192 v. DSD transcode: 10/10

 

well, turns out the DSD (and the consequent transcode) has a much different R128 value, so i had to use replay gain

 

to me, it was a perceived volume difference (some would say fullness or soundstage but i'm not fooled)

i did check all the files and the R128, replay gain etc. are pretty much the same (less than 0.5dB) other than the DSD which should be fixed using RG.  normally i can't ABX 192(or lesser) lossless from mp3 320 (or even 256).  me thinks there is something else happening that i'm just not picking up quite yet

 

anyways fun to play with

post #2393 of 3125
I put a a pair of polarity test files in the alt.zip over on diyAudio since I can't attach them here
 
 
also included the LTspice file that generates the .wav

 

edit: rethought dither and concerned that I may not have LTspice waveform data compression turned off so I reposted as audio.zip in the same diyAudio thread


Edited by jcx - 3/3/14 at 6:04pm
post #2394 of 3125
Quote:
Originally Posted by bigshot View Post
 

 

What happened to the sample of the trumpet that you said sounded clearly different with reversed polarity than correct? Are you still going to post that for us to hear? I'd be very interested to hear that because I've never been able to hear the difference between different absolute polarities before.

That recording of trumpet sample(s) will take place on March 9, 2014. It will be posted a few days after that.

post #2395 of 3125
Quote:
Originally Posted by bigshot View Post
 

 

People who do audio restoration of older recordings have a psychoacoustic trick to prevent recordings with limited high frequency information from sounding muffled. They introduce a little bed of low level, high frequency hiss. The ears hear the hiss and don't miss the lack of high end as much. A severely band limited 78 sounds a lot better with a bed of hiss than clean.

 

That's what is going on with your phono cartridge. The LP itself probably has little or no actual signal above 16kHz or so. But a cartridge that reproduces the surface noise in the upper frequencies tricks your ear into thinking it's hearing frequencies that aren't really there. All of it is probably in the range of 16kHz or lower. A cartridge rated to 20kHz probably starts rolling off the high end well below that limit.

Actually, that can be the case with restorations of 78s.

 

LP itself DOES have quite a healthy output at 20 kHz ( and above ). I just played some of my DSD recordings of various LPs using Foobar 2000 that also features spectrum analyzer. Better recordings do show output at 20 kHz, CLEARLY in beat with the music, NOT random noise, with the average peak level approx - 40 dB to the maximum in the midrange/bass - according to the music. These levels are quite comparable with CD; in the early days of CD, magazines used to publish the difference in spectrum of LP and its CD counterpart in record reviews - and differences were a few dBs, mainly in the bass, where tracking ability of the cartridge and lenght of time per side of a LP dictated compromises - less so in the treble.

 

Probably in cartridge frequency response will not do it. It can be precisely measured, at least to within the tolerances among various test records; that is a couple of dBs either way, but decent cartridges have no trouble reaching and exceedeing 50 kHz. It is possible to accurately measure the frequency response to approx 67 kHz using test records recorded at 33 1/3 RPM with signals up to 50 kHz - by playing it back at 45 RPM. Needless to say, only the best carts need to apply; most will have severe troubles up to 50 kHz, let alone 67 or so... - an inferiour cartridge will destroy high frequency signal of the test record in a single play...

 

Unfortunately, the best ones are no longer available - for decade(s).  It is true that the higher in frequency one goes, the higher is distortion of phono cartridge. There were a handful of truly excelent designs that could maintain both frequency response and exceedingly low distortion to at least 40 kHz - but I will not name them, as they are nowadays soooo rarely available for sale that any more positive feedback would simply drive the already high prices into the stratosphere. There are much more prospective buyers than cartridges available as it is, no compounding of this problem necessary. 

 

The main attribute of a truly extended response with very low or no deviation from linear cartridge is - freedom from the vinyl noise, particularly ticks and pops.  Records themselves do not noise, most of the noise we perceive as such is the result of mechanical resonances - from stylus tip to the subchassis and/or plinth of the turntable. The same LP can be perceived as noisy or completely benign as far as noise is concerned - depends what is used to play it. 

post #2396 of 3125
Quote:
Originally Posted by analogsurviver View Post
 

LP itself DOES have quite a healthy output at 20 kHz ( and above ). I just played some of my DSD recordings of various LPs using Foobar 2000 that also features spectrum analyzer. Better recordings do show output at 20 kHz, CLEARLY in beat with the music

 

Probably noise caused by groove wear or distortion in the original cutting. 20kHz sound only exists in cymbal and triangle hits, and even then it's masked by the much louder lower harmonics and fundamental. If it exists in music at all, it would be spread out with long gaps of no super audible frequencies between just the right cymbal crash. If it follows the beat, it is almost certainly distortion, not signal.

 

Very high frequencies made for very delicate groove modulations, particularly in inner grooves. After a few playings, they would turn to distorted mush. That's why most LPs have a rolled off high end, giving that "warm vinyl sound".

 

Surface noise like ticks and pops most definitely do come from the vinyl itself. A tonearm resonance can only add a few samples of ring off to the tick or pop, making it a little harder for digital declickers to remove.

 

You're talking in an area that is one of my specialties now.


Edited by bigshot - 3/3/14 at 7:28pm
post #2397 of 3125
Quote:
Originally Posted by bigshot View Post
 

 

Are you talking about a big difference when you say you could hear a difference between -90dB and -100dB crosstalk? That was the comparison that I was asking about.

 

Expectation bias affects everyone. But it's much more likely in a person who has their ego invested in hearing things other people can't (i.e.: audiophiles) than in regular people. I would say that blind testing is probably more important for you and I than an average person. Especially since being honest and accurate about what we hear is more important to us.

-90dB and -100dB crosstalk difference is not that audible at first; it is best appreciated only after listening for extended period to 100db device and then switching back to 90 dB one. 

 

So fine perceptions are comparable to listening at concerts. No experienced performer will put the composition he or she wants to present to the audience in the best light possible at the very beginning of a concert - there will be those arriving late ( caught in traffic, etc ) , with mind still fixed "did I park the car in the zone allowed for parking or not " - and not on music itself. It takes about 5-10 minutes to an average person to "calm down" and starts to truly follow the music - and experienced performers will put some "warm up music" at the beginning of the concert. Similar is with 90 and 100 dB separation devices - quick A/B will most likely not tell you anything, because you have not yet reached the concentration etc necessary. 

 

Whenever possible, I do use blind testing. But you can not always get another person to switch the gear for you while developing the final version of the modification for any audio device - not n times in a row - where n is quickly approaching high double figure.  There are practical limitations to this, unfortunately.

post #2398 of 3125

I am concerned about your hearing. If you are spending long periods of time listening to music at extreme volumes to hear noise down at -90dB your ears have to be thrashed by now. Take care of your hearing.

 

Blind testing is required. Find a friend to help. I think you are quite a bit more susceptible than most to expectation bias.


Edited by bigshot - 3/3/14 at 7:38pm
post #2399 of 3125
Quote:
Originally Posted by bigshot View Post
 

 

Probably noise caused by groove wear or distortion in the original cutting. 20kHz sound only exists in cymbal and triangle hits, and even then it's masked by the much louder lower harmonics and fundamental. If it exists in music at all, it would be spread out with long gaps of no super audible frequencies between just the right cymbal crash. If it follows the beat, it is almost certainly distortion, not signal.

 

Very high frequencies made for very delicate groove modulations, particularly in inner grooves. After a few playings, they would turn to distorted mush. That's why most LPs have a rolled off high end, giving that "warm vinyl sound".

 

Surface noise like ticks and pops most definitely do come from the vinyl itself. A tonearm resonance can only add a few samples of ring off to the tick or pop, making it a little harder for digital declickers to remove.

I would love to have analog master tape, pressed analog record and digital "whatever" of the same recording - and compare those. 

 

I agree that fundamentals are much lower in frequency and much higher in amplitude - even in cymbal and triangle. But harmonisc should follow the beat.

 

I agree very high frequency make for a very delicate groove modulation - and that "average" equipment unfortunately turns them into distorted mush - particularly in the inner grooves. However, using available technology, not the generally no longer available one from the 80's (when there was peak in phono playback equipment quality ), it is possible to all but eliminate these effects.  But it is absolutely incorrect that these effects cause warm vinyl sound - wear and tear on vinyl records INCREASE high frequency response and add distortion, making treble more prominent and in extreme cases harsh - most definitely not warm.

 

Surface ticks and pops can get extremely suppresed by the correct choice of materials - starting with cantilever of the cartridge>suspension>generator>mechanical interface of cartridge to tonearm>tonearm headshell>tonearm tube>tonearm bearings/tonearm base - etc, etc.  The use of stone materials for cantilevers, such as sapphire, ruby and diamond, is NOT a gimmick - Dynavector used to offer both ruby cantilevered Karat cartridge (at lower cost) and diamond cantilevered one (at higher cost). There is marked difference between the two - and it is also evident that diamond one is MUCH quieter in the groove. All other things but cantilever material being equal. Ruby cart is now long history, but DV17D3, as the latest incarnation of Karat Diamond is called, is still going strong - after 35 years since the original DV100D made its debut in 1979.

 

One can always tell which cart is better - by listening to the "needle talk"  when playing back a vynil record, without the turntable connected to the rest of the system.

The one that is the quietest will always win...

post #2400 of 3125
Quote:
Originally Posted by analogsurviver View Post
 

I would love to have analog master tape, pressed analog record and digital "whatever" of the same recording - and compare those. 

 

I had that opportunity. A record I produced way back when was released on both vinyl and CD. We recorded on 24 track tape. The CD sounded exactly like the master. The record didn't. Not surprising because we output the master to 4 track ADAT, and the ADAT sounded exactly the same.

 

The way to minimize pops and clicks is to adjust the stylus tip size and shape to slide in under the band of groove wear. The tonearm and base of the turntable have very little to do with it.


Edited by bigshot - 3/3/14 at 8:12pm
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