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

We have a similar device. When I bought it I plugged it in and waited for the dog to doze. Then I turned it on. He lifted his head and looked around, then got up and quietly left the room.

Whilst the cat's not too bothered about my ultrasonic cleaner (the energy pretty much stays in the liquid), he gets extremely  distressed if I dare to switch on the ultrasonic leak detector that I use for door seals, dodgy walls, etc. This puts a lot of energy into the air at 40kHz, and he can hear it from several rooms away - enough of this energy gets around pretty much any normal house door, and it's well within his hearing range - which according to some sources goes up to about 64kHz - way beyond a dog's, which on a good day will extend to about 40kHz tops. Porpoises and dolphins have probably the best range though - it extends up to about 150kHz.

Thanks, Andy.  I've just spent a happy hour going through http://db.audioasylum.com/cgi/search.mpl?author=EBradMeyer&user_id=45230&forum=ALL&sortRank=None&sort=date&sortOrder=DESC which is one of the author's responses to criticisms of the paper.  It makes the most delicious reading.  I should probably have been doing other things but I just couldn't stop reading the repeated nailing of "audiophiles" to the wall.

So I'm at SBES the other day - Wildduck and ryclark have departed, and I have to hang around for my train, so I went over to the Tannoy stand and had a look at their current monitor range. Tannoy's MD is there, and I asked him to explain about the supertweeters they now fit - response up to 50kHz... You have to bear in mind that I have a badge on that says Acoustic Consultant, and he'd obviously clocked this. My opening question about them is "so you're marketing to bats these days?"

The next five minutes was fascinating. Apparently, although we can't hear anything coming from these supertweeters, they improve the apparent performance we get from their monitors. This information was imparted to me (I didn't interrupt - it was wonderful!) with so many caveats, exceptions, you name it, that I wouldn't have had a pair of them if he was giving them away!

But he's not giving them away at all - they cost a bloody fortune if you buy the retrofits. He knew that he wasn't about to sell me anything, because I'd already told him that I had a pair of Tannoy Devons (flat to 20kHz with no supertweeter) that I was quite happy with as location monitors. But apparently I almost hadn't lived until I'd heard this extended response... (perhaps)

Eventually I told him that I had a pair of Adam P11's as well, and that I couldn't hear any important HF differences if I monitored on those. And that's with mics/pres that he's certainly not going to argue with, so that's okay... He asked what the claimed response of the P11 system is, and I pointed out that the ribbon tweeters in them measure inherently flat up to about 35kHz.

He didn't actually go as far as to accuse me of being deaf, but I'm sure he wanted to. I reckon that my hearing's at least as good as his - and probably better. But I can't hear up to 20kHz - or even get that close, come to that. But I never get complaints about HF levels at all. There is some serious BS going on here, I think!

For once I'm currently recording a CD of piano works at 24/96.  I've just looked at one long file of takes, scanning selection in AA frequency analysis, and basically there's nothing but noise above say 16kHz.  At least with this material, there seems to be no point whatsoever in the higher sampling rate.  I was sufficiently amazed by what I saw that I've just set the equipment up in the kitchen with the anti-rat HF generator, and it is actually recording in the 20kHz+ range - so it's not an equipment defect.

Same with organs, often noted for having a somewhat 'shrill' sound - which means that there's often a lot of HF content up to around 17kHz or so, but nothing of any significance at all above that - just noise. Even with brass instruments, where there are sometimes local artefacts above 20kHz, you wouldn't want them there anyway - they don't enhance the resultant sound one bit!

And it's not that I'm failing to capture what's there - all the mics I currently use have a response that's essentially flat up to 20kHz, although the DPA 4006's can be altered acoustically to reduce or extend this somewhat, with different polar characteristics.

With real recordings of real instruments in real rooms, radiation above 20kHz reaching either microphones or audience to any significant degree is a myth.

Just to be sure, before this morning's session properly started (ugh! Sunday morning sessions are not my favourite!) I walked round the piano jangling my keys while recording - which generates a surprising amount of sound above 20kHz - and later I'll verify that it shows up, and that therefore there's no doubt that the lack of HF elsewhere in the recording is not my fault.  The instrument does sound perfectly bright - possibly a bit over-bright, if anything.

Just to add that I've now looked at a frequency analysis of a keyshake test conducted at the start of the most recent session, as compared with the analysis of the subsequent piano recording - this confirms that the equipment was recording well past 40kHz but that the piano recording only has noise above 16kHz or so.  To my mind this proves that for solo piano, anything more than 44.1Khz is a complete waste of effort.  (It would be interesting to analyse any SACD solo piano recordings there may be).  Other instrumental forces may well produce quite different results, though.

Even if these frequencies accidentally reach the mics, I still don't see how they could be significant - I can enjoy music just as much without them, and I always have done.

What has always intrigued me about this is that all recordings and reproductions are in themsleves very poor reflections of what it was like to actually be there anyway - so why is there so much fuss made about a part of what's perhaps present near the performers only anyway? It's certainly not the impact of ultrasonic frequencies that makes recordings a pale shadow of the real thing, is it?

In other words, if you made a recording such that when it was played in your living room, it effectively transported you to the location (in audible terms), I think that the shock of that much realism would rapidly make you forget all about the possibilities of ultrasonic frequencies  - they wouldn't even be the least of your listening experience, because you wouldn't 'experience' them anyway unless you sat amongst the performers - perhaps - and who would want to sit there for a listening experience?

unless you sat amongst the performers - perhaps - and who would want to sit there for a listening experience?

The producers of not a few "surround" (i.e. 5.1) recordings, I'm afraid.  I have certainly read one arguing that it must be preferable to sit in the middle of a string quartet!

And on the realism bit, that is why I have long been a supporter of developments like ambisonics - even though this is still doomed to incomplete success because of the remaining influence of the listening room (which may also be why ambisonics is most widely used for large-scale sound projection).

Paul

unless you sat amongst the performers - perhaps - and who would want to sit there for a listening experience?

The producers of not a few "surround" (i.e. 5.1) recordings, I'm afraid.  I have certainly read one arguing that it must be preferable to sit in the middle of a string quartet!

Yes... I'm aware of them. Fortunately for common sense, they don't count. If they persist in trying to sell gimmiky sound, then as far as potential purchasers are concerned, they are going to fail. And who's that doing any favours for? Pretty much nobody except themselves, as far as I can see.

I have no objections in the slightest to ambisonics, to the limited extent that it works. But even to get that far, it's staggeringly impractical - which is why it will never catch on. I've tried a few ambisonic experiments with my Soundfield MkV, but in practical terms, I've only ever used it as a steerable stereo mic with some rather useful post-production characteristics. And I've heard a few of these larger-scale ambisonics demos too. Every single one of them has not caused the suspension of acoustic disbelief on my part... although I'll freely admit that they could easily have been improved in acoustic terms; the venues weren't really ideal for any sort of reproduction, never mind surround.

I have no objections in the slightest to ambisonics, to the limited extent that it works. But even to get that far, it's staggeringly impractical - which is why it will never catch on.

Since when was "practical" the main consideration?  Stereo was initially seen as domestically impractical; quad was seen as impractical; but none the less, quite a lot of people now have a grotty 5.1 system - and I believe it is possible to coax a better impression of space out of those systems using ambisonic techniques than by using the weird and wonderful collections of ironmongery with microphones sticking out of them that I have come across.

Paul

Since when was "practical" the main consideration?  Stereo was initially seen as domestically impractical; quad was seen as impractical; but none the less, quite a lot of people now have a grotty 5.1 system - and I believe it is possible to coax a better impression of space out of those systems using ambisonic techniques than by using the weird and wonderful collections of ironmongery with microphones sticking out of them that I have come across.

I think that practicality is a consideration for a lot of people, actually, and that 2 was a good number for a lot of practically-minded people to stop at, both in terms of being able to manufacture the apparatus to record and play on, and in terms of domestic acceptability. Heaven knows, it's been hard enough here to get even a couple of decent loudspeakers into our living room (we are currently in a failed state from that POV), never mind 5.1 - *SWMBO's objected completely and utterly to this, even though it would be mostly for her benefit, because I'm not the one watching the films. And I know of a lot of similar households...

I've personally yet to see a well set up domestic 5.1 rig, although I've been told that there is one somewhere... and all of the attempts that I've seen have been flawed to the extent of being no more than effects systems, and not very good ones at that. But since that was all that the format was really intended for, perhaps that isn't so surprising.

I agree entirely about the strange hardware concoctions though - no good will come from any of them, and technically they make no sense. AFAIK the only strange hardware multi-mic concoction that's ever found any degree of long-term acceptability is the Decca Tree, and that's only really necessary to compensate for the appalling state of most listening situations. But those strange five-arm constructions with the Neumann mics on look for all the world like gold-plated turds, and probably sound that way too. Have you ever heard anything that's knowingly come from one? I don't think that I have.

*If you get the impression that SWMBO doesn't appreciate good sound, you'd be right - she has other stirling qualities, though, and much better visual sense. That said, I am getting a bit fed up with all organ music being referred to as 'hooting'....

I've never seen a domestic installation of a 5.1 system.  Plenty of stereo systems with one speaker on top of the bookcase and the other behind the sofa, though.

Debates like this are always fascinating - apart from anything else, it forces us to confront the prejudices and experiences of others.

I have seen the results of my colleague ozpeter's experiments with the WMD (Weapon of Marsupial Determent) which are perfectly valid.  The results on the piano are as one expects for such a large scale high inertia source.  However the key jangle tests might be more representative of cymbals, bell trees, and sitars plucked or struck with hard objects.  Now whether he found the key jangles more realistic and musically satisfying, we didn't get round to ...  (And I'm not sure that I would want to listen to these sources at the distance the mics are usually placed.)

The AESJ paper at the heart of this is interesting but I would have some qualms with details of the methodology and configuration.    But publication by a learned society is merely an invitation to others to attempt to replicate the test and achieve the same results.  Wait a year or so and see what follows (Malcolm Hawksworth, over to you ...)

There is an inherent bias in some of the comments here that by the time (through diligence and experience) we achieve the status and respect of audio luminary, the usual process of decline has set it, and the top octave of our hearing capability is a distant memory (like me - my left ear is 60 years old, my right ear is 40 years old, stereo monitoring on headphones is most unreliable).  But those of inferior years who have not reached luminary status but have their hearing by and large intact may have a different view of that top octave.

I am much more inclined to look at differences in the amplitude/time response of different configurations rather the usual amplitude/frequency.  And I want to know if the results can be duplicated in different populations (European, Asian, South American).  Maybe somebody like Prism could produce a version of their converters optimised (doesn't that beg the question) for 16/44K1 and compare the results with other configurations including say 88K2/24 native, and likewise subsequently reduced to 16/44K1 all played back on the same configuration.

But I'm also a broadcast engineer (pragmatist) and I know that even 16/44K1 exceeds by a wide margin the capability of our broadcast chain so recording straight to CD is highly satisfactory for our primary purpose.  And I recall my dealings with a Sydney based audio guru from whom I purchased many years ago my long neglected wideband AM tuner.   This is someone who would 'upgrade' your favourite bit of audio gear to remove all those nasty commercial impediments to good sound.  He remarked that the best sound available to him was direct broadcast from the Sydney Opera House via ABC-FM.  For this particular situation, it was physical program lines from the OH to Broadcast House, through broadcast standard analog gear (and some switching equipment that might have been a bit passe) and out again by physical program lines to the transmitter.   The amount of transformer iron in this circuit would endear it to some of the analog fraternity, but for me the  killer was knowing that everything went through a rolloff above 15 khz and significant (>50dB) attentuation at 19kHZ.   So promoting his gear as having response extending way beyond 20kHz was maybe a bit of hypocracy on his part ...

Jeremiah (crying in the wilderness) Ch 17 v 9 (King James) says:  "The heart is deceitful above all things, and desperately wicked: who can know it?"  Remove the first and last letter of the second word, (error in translation?) and the result is equally valid.

The AESJ paper at the heart of this is interesting but I would have some qualms with details of the methodology and configuration.    But publication by a learned society is merely an invitation to others to attempt to replicate the test and achieve the same results.  Wait a year or so and see what follows (Malcolm Hawksworth, over to you ...)

That's been discussed by others - mainly people who will not believe the outcome, even if the rest of the world accepts it. Certainly Greisinger's researcher's credentials, and his research methodology are beyond dispute as far as I'm concerned - speaking as a researcher. The right thing was done, in the right way, as he always would. But I'm slightly more concerned about some aspects of some of the Brad Meyer/Moran setups, I must admit...

There is an inherent bias in some of the comments here that by the time (through diligence and experience) we achieve the status and respect of audio luminary, the usual process of decline has set it, and the top octave of our hearing capability is a distant memory (like me - my left ear is 60 years old, my right ear is 40 years old, stereo monitoring on headphones is most unreliable).  But those of inferior years who have not reached luminary status but have their hearing by and large intact may have a different view of that top octave.

Well, I might be getting older, but I have a perfectly fine memory. I can recall being able to hear dog whistles well into my 20's (which with hindsight proves, I suppose, that my hearing range may have been a bit more extended than I thought, because most of my peers couldn't do this). The other thing I can remember well is what real instruments sounded like then, in comparison to good recordings. And with individual instruments known to exhibit ultrasonic sound (mainly brass - they are actually the worst offenders, I think), you could achieve results which, if listened to on good monitors, sounded timbrally pretty much identical to the real thing - without the ultrasonic part being recorded at all, because the analogue equipment response stopped a little short of 20kHz.

I was lucky - I actually had the opportunity to experience this as a part of somebody's research. But I do recall, even then, realising that anything that actually had a flat response up to 20kHz was going to do the business, regardless. So if I'm biassed - which I might well be - it's because of an experience I had at an age when if there was a difference to be heard, I probably would have heard it.

So regardless of whether one could actually hear the ultrasonic content or not, I still don't think that it makes a scrap of difference worth having to the percieved timbre of an instrument.

I am much more inclined to look at differences in the amplitude/time response of different configurations rather the usual amplitude/frequency.  And I want to know if the results can be duplicated in different populations (European, Asian, South American).  Maybe somebody like Prism could produce a version of their converters optimised (doesn't that beg the question) for 16/44K1 and compare the results with other configurations including say 88K2/24 native, and likewise subsequently reduced to 16/44K1 all played back on the same configuration.

Without getting into a huge discussion about it (and it would be huge), I have to say that the converters themselves are nowhere in this (excluding anti-alias filters of course), because the single largest distorter of transients is the transducer that gets them back into the air - by a long, long way. Even the best normal monitors you can get make quite a mess of transients (for anybody else wondering, that's the initial amplitude/time response of a loudspeaker/headphone). And it's for this reason that the only room system that is least likely to create massive transient smear is the 4th one in Brad Meyer/Moran - the system with the ELS's in it. That would have an exemplary step function response, and the lowest transient smear you can achieve. The only other things that get close are small full-range drivers like Auratones, but they're not a patch on an ELS.

The listening test I did was using original Quad ESL57's, incidentally, and the rest of the chain was state of the art (back then) analogue.