"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...