"SACD and DVD-A proven no better the CD in a year of listening tests"

I do recall reading early on in my (self-trained) audio "carreer" of some pretty complex mathematical constructs that basically "deconstructed" HF components into (very low-level) modulation artefacts of lower frequencies. It was mostly out of my league, but the gist was that there WAS (past tense?) some argument that HF components could modify low frequency components (mostly low-level lower frequency) as harmonics.

I don't recall any papers ever where anybody actually tested this rigorously and came up with a statistically meaningful result in terms of being able to percieve any differences - I think largely because the ear can deconstruct whatever's there to a large degree, and if an additional component was added, the ear would effectively remove it again if it wasn't recieved (by mechanical means) in the first place. There is, however, a body of research that indicates that extreme HF content makes no difference whatsoever to pitch determination, or the perception of timbre...

I know that reading the original blog report left me with a bunch of questions about the methodology, the characteristics of the sound source(s) (identical isn't necessarily NOT a variable, if the characteristics were limiting all the audio experiments - a cardboard woofer and a $2 tweeter would definitely make someone think that there was no difference between a well-mastered HD recording and a 22k downsample of the same thing), but I have to assume from other comments here that no part of any of the equipment used was limiting or colouring the results in any way.

One of the reasons for testing this on a variety of systems is to eliminate some of the issues that go with the concept of 'identical' - by testing on a variety of systems that have been determined to be 'good', and not relying on one system in particular. But as far as I'm concerned, if you can't tell the difference when you use exemplary equipment with Quad ESLs (which have staggeringly good/accurate transient and phase response) then it simply ain't there - which it isn't, of course.

Maybe they should have used Monster (TM) Oxygen-Free (R) Coaxial 240V cable...

We have a thread about that somewhere - there are circumstances where that appalling monster stuff can actually make things worse, not better!

I'm sitting here listening to an Earthworks demo CD (www.earthworksaudio.com) for their "HDM High Definition Microphones" which tout impressive impulse response (i.e. reduced ringing following an impulse) and flat frequency response to as high as 50Khz.  They're suggesting that this accuracy improves the detail and believability regardless of the audio chain (44/16 CD valid, so are cheap mixer preamps) because the accuracy affects the entire frequency spectrum.

I don't immediately hear more detail; I hear a more aggressive mid-upper midrange, which flatters some things and sounds unnatural on others; and I hear more room ambiance (translate: short reflections/slaps).

So if any of you want to go after a technical writeup about this (Steve, is this a bunch of stuff not strewn together very well, or is that just the state of my flu-recovery brain?),  here's an article that serves the purpose.

By the way, the author of that article is David Blackmer, founder and engineer of Earthworks, and rather notably also the founder of DBX.  No slouch engineer.

By the way, the author of that article is David Blackmer, founder and engineer of Earthworks, and rather notably also the founder of DBX.  No slouch engineer.

Yes, but it's still self-serving, isn't it? And on that basis, I'm afraid no credence can be attached to it.

How many independent ABX tests has David Blackmer taken part in where the results have been published? Can you find any at all? I'm afraid that in the real world, none of his claims have been shown to be repeatably demonstrable.

And as for his reputation - well, it's very easy to trade on your 'reputation', and in Blackmer's case it helps to recall that this was the man who foisted the DBX noise reduction system (with some apalling aretefacts) onto us with no apologies at all. Personally, I can't take anything he says about 'quality' too seriously.

DB also introduced a delta-modulation digital recording system in the early '80s (I probably have the AES pre-print hidden somewhere)  along the lines common at the time.  Processor which outputs data on a video pedestal, recorded on a one-inch helical.  One majpr issue at the time was variable quality of world-wide distribution of cutting masters.  Put the digital recorder across the output of the cutter feedback coil as usual , but then clone it as many times as needed and send them off. Each one identical to the original.  Better than the 4th or 5th generation dub that often turned up.

The exact specifications (clock frequency, effective S/N) elude me, but there was some degree of integration in the coding to deliver appropriate signal to noise, possibly some analog compansion as well.  However, I clearly remember that the perception of the AES group listening to the results, was the improved (it's that word again) "musicality" of the result.   Possibly the better standard of conversion, possibly the lack of sharp cutoff anti-alias filters, maybe the higher tolerance of the ear to slope overload rather than peak overload, and the suitably of delta modulation for a basically triangular spectrum.  Of course all the production issues that plague DSD applied equally then.  Now confined to the garbage bin of history ....

How many independent ABX tests has David Blackmer taken part in where the results have been published? Can you find any at all? I'm afraid that in the real world, none of his claims have been shown to be repeatably demonstrable.

No disagreement here...  I don't have the time and motivation to do this justice, and the foregone conclusion would of course be NO!  Yes, it is self-serving by definition -- it's company propaganda masquerading as a white paper.  I wish an independant someone would do the work, though.

And as for his reputation - well, it's very easy to trade on your 'reputation', and in Blackmer's case it helps to recall that this was the man who foisted the DBX noise reduction system (with some apalling aretefacts) onto us with no apologies at all. Personally, I can't take anything he says about 'quality' too seriously.

And like Dolby B tapes, almost none of which are correctly trackable anymore, was the Holy Grail?  This is a pick-your-poison issue -- using DBX to record piano on cassette was a bad idea.  But the way that system worked allowed me to record things in the pre-digital days that were impossible any other way.  And those tapes still "track."* 

Whether obscure early-digital recording, industry standard compressor-limiter devices, or noise reduction, DB's achievements warrant that this be given at least a thorough look-over, in my opinion.
Which, perhaps, we have just done.



*Actually, its success was its downfall.  Using DBX in a quality system preserved so much extra source detail that the inevitable noise artifacts seemed particularly out-of-place. 

I remember watching an Imax movie (Chronos) where the audio, played back on a 35mm interlocked 6-track mag dubber, used DBX I rather than Dolby A, and in the theater noticed as the audio crept up from silence that hiss was pumping in...    No doubt you'd hear this on a DVD copy too!  But killer dynamic range?  Well, you know.

*Actually, its success was its downfall.  Using DBX in a quality system preserved so much extra source detail that the inevitable noise artifacts seemed particularly out-of-place. 

Yes... and even applying NR to the results doesn't end up giving you an acceptable result either - I tried.

To be fair, the system worked well enough if applied per track to multitrack systems where you only got one instrument per track - as long as that instrument wasn't a piano! I still preferred Ray Dolby's more advanced systems, even though they were harder to set up properly. At least he'd thought about the pumping problem...

[THIS]

Snake Oil alert!  If money is no object, you can have THIS for your home theater, with speaker response from 1Hz to 102.5Khz.  Sounds great to me -- especially if someone else is paying for it!

with speaker response from 1Hz to 102.5Khz.  Sounds great to me...

I read somewhere in the blurb that the response of the system includes DC. Since air is an elastic medium, I suspect that this might be a tad unnecessary...

These highly specialized musical instruments feature outboard passive cross-overs and the most exotic of wood cabinetry - African Sapele.

Sapele isn't exactly ideal, or idealogically sound either, for speaker cabinets, and anyway, aren't you supposed to view your cinema in the dark? What's the point of the (might look exotic, but...) sapele, then? And a loudspeaker is a musical instrument now? How much skill does it require to learn to play it?

What?  Get real!  If you paid that much for your sound system and a video projector that would put out daylight brightness, you'd leave the lights on too so you can sit in constant admiration of your extraordinary achievement, and hope that everyone else is drooling too.  Hee hee...

I read somewhere in the blurb that the response of the system includes DC. Since air is an elastic medium, I suspect that this might be a tad unnecessary...

 
Surely this is merely a measurement of an over-achieving HVAC system!

Surely this is merely a measurement of an over-achieving HVAC system!

Ah, but you're going to need a good HVAC to keep the room cool because of all those toobs!

(If you're in the UK, that's valves...)

This just in with the April, 2008 issue of Mix Magazine, in the "Insider Audio" feature by Paul Lehrman:

The Emporer's New Sampling Rate

Enjoy.  Smugly.

(Yes, this references the same study that was the subject of the article linked by Peter in the original post, many moons ago.)

Very nicely written.

Hey Folks

I missed to track this item for a while. Being back now I found this to be a gross error as the newly announced audio system reproducing from DC to above 100 kHz is really fantastic. Yet, for my personal use it is kind of an overkill, as there is no one left that can profit from the upper 3 octaves since the death of my 2 Abessyn cats, and, on the other side, elephants communicating by infrasonics are very rare in my region. Nevertheless I sight a very particular application for this system I would like to promote here. I think that the inventors, intending the system for Audio reproduction are rather on the wrong steamboat as we use to say in german.

In the alpine regions, especially in Switzerland and Bavaria, singular weather conditions exist dominated by a particular warm wind coming from south. It is called "FOEN" (unfortunately i know no translation for it). This badly reputed situation causes a number of problems to part of the population such as headaches, dizziness, and forces many individuals to stay away from work. The mechanism causing this is recognized as strong variations in barometric pressure bouncing up and down within fractions of an hour. Beyond the incompetence of UBS top banking managers, this is a non negligible factor influencing national income in my country.

Similar to compensation of ambient noise already realised by some companies, a low pressure compensation would be a great relief for these those suffering from FOEN. No doubt that many might be willing to pay considerable amounts for such equipment. It might be a giant step for the health system as medical treatment has shown to be rather problematic so far. I am willing to act as general contractor due to my experience gained in refurbishing old houses and to hire competend people able to seal windows and doors hermetically to keep pressure. I could even abandon my audio activities for that and might also be willing to remove the apple from my scull. Comments are NOT welcome.
 

Being back now I found this to be a gross error as the newly announced audio system reproducing from DC to above 100 kHz is really fantastic.

Just on a technical point, you can't transmit a DC excursion of a loudspeaker cone through air, because air is an elastic medium. Accordingly it tends not to stay where you put it for very long...