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

That said, I am getting a bit fed up with all organ music being referred to as 'hooting'....

You made my day...

because the single largest distorter of transients is the transducer that gets them back into the air - by a long, long way.

The day that will be better recognised a lot of companies will go out of business. I'm out of the loop these days, but is there still any research going on to improve this end of the chain? It looks as flapping cardboard is going to stay forever.

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

While I completely concur with Steve's conclusion (even when you can hear above 20Khz, the timbre of an instrument is unaffected), I think this is slightly overstated.  Lots of editing in spectral view (with B&K 4006, AKG 414, and Neumann KM-84 mics as the mic sources) has shown me what goes on above 20K is measurable, though rarely significant, and probably never audible.  Percussion, of course, gives the strongest upper energy, and loud trumpets can be pretty interesting too.  But the one that really piques my curiosity is... violins.  You can have a whole orchestra nearly drowning out the strings but still see the unique fingerprint of violin vibrato up in the 20-24Khz range -- the only thing prominent in that range!  Can you hear this?  Of course not; it's masked by the substantially louder amplitudes of the rest of the spectrum.

So pick your myth, I suppose... to the mic and Spectral View one could make the case that something significant is there.  But not to the ear.

I'll have to try this on my young kids and find out what they can hear.

By the way, Peter, if you can get piano overtones to 16Khz, you're doing well.  I usually don't see much above 11 or 12.  I suppose if you miked it a few mm from the hammers, you'd get a much more visually pleasing result (while torturing the ears to a very unmusical one!).

I think this is slightly overstated. 

I don't think it is - if it's 'probably never audible' and doesn't affect timbre, then to reach the audience to a significant degree it would have to be loud enough to cause damage - because otherwise it's not significant, as we've already established - because we can't detect the signifier. So I'd say that it was correctly stated - and although contentious on the face of it, it's not really when you examine it a bit.

And the other thing about this, of course, is that you can pick it up locally to the instruments, but nowhere near as much gets to an audience positioned somewhat further away. Most microphones tend to end up at least slighty closer than most of the audience are, and spot mics a lot closer. So from the perspective of the people listening to the recording, you've probably overbalanced the ultrasonics anyway, if you record and reproduce at a sufficient bit rate without attenuating them. As I've said before, I roll this stuff off completely - and I've never had a single complaint about it.

I think that all that violin ultrasonic detritus (on instruments that can be pretty excruciating in the wrong hands, and sometimes in the right ones...*) is probably enhanced by using too much rosin. Best thing to do with that is roll it all off regardless, and do the dogs and cats a favour. Also, on reproduction equipment with less than stellar intermodulation distortion performance, it's probably going to sound better like that anyway, because it won't be exciting problems.

I think that there's quite enough to worry about when making recordings at the best of times without worrying about the stuff that you can't hear as well. I think that recordists should concentrate on getting the best out of performers rather than trying to confuse the domestic wildlife, myself.

*One of my sisters played a good violin extremely badly as a teenager, and it regularly set my teeth on edge. I was mighty relieved when she gave it up, and concentrated on singing instead. Fortunately my own children have all veered away from anything that's bowed and even my other sister, who played the cello for ages, now only plays the double bass - so I'm spared these days!

As an aside, this Cymbal stop is apparently a solely Polish invention - lots of tiny untuned pipes on a single foot for each note.  I guess that close up there's lots of ultrasonics there, and even at a distance it's hardly likely to be described as "hooting"!

Paul

As an aside, this Cymbal stop is apparently a solely Polish invention - lots of tiny untuned pipes on a single foot for each note.  I guess that close up there's lots of ultrasonics there, and even at a distance it's hardly likely to be described as "hooting"!

I doubt it very much - and that's based on some recent experience with a load of misbehaving pipes that small in an organ with a lot of short-footage mutation stops. The timbre you get from pipes that length is quite pure in harmonic terms, and doesn't extend beyond the normal hearing range at all. The reason that those cymbal stops are built like that is precisely because organ pipes of this nature don't produce a lot of extended harmonics - but if in that case, it's an artificial HF 'chiff' noise they wanted to add, and that seems like a sensible way to save a lot of extra action-building that you don't need.  In principle, there's no reason why you couldn't use the same approach with the top pipes of a cornet, only with tuning slides on the pipes, so that the result was harmonically related. But with either case, you need the small pipes, because it's a lack of harmonics that you are trying to overcome.

You are more likely to get ultrasonic output from some much longer reed stops on some organs, because of the way that they resonate - in a similar way to what happens with a trumpet. In a trumpet, it's the body itself resonating that causes the ultrasonic output, not the excitation as such. But generally this doesn't happen much with organ reeds either, because the material that most pipes and resonators are made of is relatively well damped, and supported. Both of these factors reduce the potential for ultrasonic emissions quite significantly. In an organ with decorative en chamade trumpets, it might be a different matter when it comes to ultrasonic emissions altogether, though.

So, in my recording of the organ I had the trouble with, there is no output above about 17kHz at all. But, I still think that in many ways, it sounds over-bright. That wouldn't matter so much if this was balanced out a bit better, but it still has some pedal deficiencies, as far as I'm concerned. And if they can sell enough CDs, then perhaps the church's music trust can afford to rectify this. And yes it has to be the music trust - it's the only part of the organisation that's truly viable these days in financial terms, because it's the only bit that draws the crowds.

By the way, Peter, if you can get piano overtones to 16Khz, you're doing well.  I usually don't see much above 11 or 12.  I suppose if you miked it a few mm from the hammers, you'd get a much more visually pleasing result (while torturing the ears to a very unmusical one!).

For once I actually measured the distance from the piano to the mic as I have to recreate the same sound for the last session in a couple of weeks time (well, from the tail leg of the piano to the mic stand) and it was 2.6 metres - FWIW.

Meanwhile a quick check of the recent organ/choir recording I mentioned the other day - which was only 16/44.1 - reveals stuff all the way to 20kHz and more, but watching the waveform, most of the HF content simply relates to esses.  Looking at an organ solo portion only, there seems to be nothing describable as significant about 18kHz at the most.

Interesting stuff!

That all makes a lot of sense. Just in the interests of investigating, I'll record my next session at 88.2k, which the HD24 has no trouble with, and see what, if anything, occurs that I may have missed - apart from echo-locating bats, that is...

[1. Ears:]

The topic discussed here is a highly interesting one and I hope not to offend any of the established masters by plugging in lately. To state it at the very beginning: I consider the distribution of stereophonic material in a higher resolution than the red book standard as a waste that is aimed at the psychoaudiofidelists that consider gold plated AC power lines as an indispensable prerequisite.

Despite that global remark I would like to expose some more detailed experience and opinions. I try to structure this a bit as otherwise, not using my native language, I am prone to get struggled.

1. Ears: When I was about 14, I had the chance to test my ears at an audio fair and people and myself were astonished that I could perceive 22 kHz. At that time I also remember that blowing a dog whistle close to me caused heavy pain. BTW: I was never asthmatic but suffered from many middle ear inflammations. At 20 to 24, when I was working as a part time sound assistant in early TV to earn money for my engineering studies I also recall that all the 15.625 kHz singing from the monitors was annoying. That has gone as my ears are 70 (both !) and have a cut off at 13 kHz, which is reasonable for my age but bad for Hi-Fi. Nevertheless I assume that I still can distinguish between good and bad sound reproduction. Question: Should we provide frequency response to beyond 40 kHz just to repeat the pains of a dog whistle to some eccentric people as I was (and still am) ? NO !

2. Ultrasonics: The battle is still open about how much spectral power is produced by different sources of sound. I tend to assume there is much more ultrasonic content as commonly believed. This holds certainly for many (nasty) types of noises such as brakes of trains, rattling chains or pressurised hammers. With respect to piano, I have some controversial opinion as to the limits stated as 11 – 12 kHz or 16 kHz. I have recently recorded piano recital, experimentally in 88.2/24 bit format. In AA, I found some spectral traces up to 24 kHz. You may argue this as deficiencies of my recording equipment and not a real acoustical content. I can neither prove the one nor disprove the other. Listening to the original 88.2/24 file and the reduced one to 44.1/16 did not reveal the least difference. Thus, my initial statement stays, hopefully not only due to my personal lowpass in the ears. Unfortunately, a recent Jazz session I had taken only in 44.1/24 format – yet there are components up to 20 kHz. Question: Does the possibility of ultrasonic presence influence the quality of recording and reproduction ? NO! (Except the dog whistle for borderliners)

3. Microphones/Loudspeakers: The majority even of well reputed microphones are not suited for ultrasonic recording. The exception known to me (apart from some types built for measurement ) is the one of Sennheiser. The commonly used small diaphragm types may extend slightly beyond 20 kHz, depending on size. The family of large diaphragm microphones are physically limited to an edge frequency below 20 kHz. Among these is also the admired Neumann U87 which is down 10 dB at 20 kHz in cardiod position and even worse in figure of 8. Despite that I would vividly welcome to get a pair as I cannot afford them for personal use. For loudspeakers there is much more need to get an overall smooth response and a rigid low fundament. The latter is often lost in the modern trend to small cabinets. I admit the ribbon high frequency unit of the PA11 as a very brilliant (sometimes a bit overly) reproducer.  For the overall impression I like to stick to the old 15” Tannoy coaxials in a Westminster-like cabinet, especially when refurbished with a new rubber suspension. My Abessins, unfortunately they passed away 4 years ago, indicated a sine close to 20 kHz by a very strong look at me. They could only be stressed when playing back the purr of an unknown cat. It is a shame that Tannoy corrupted their own elegant coaxial principle by the 50 kHz units, that are neither coaxial nor make otherwise sense. In my eyes it is a step down from the reputation as for at least 2 or 3 decades, the Tannoys were the only monitors found in the studios of Swiss National Broadcast and TV. Question: Is it a primary sign of quality that microphones and Speakers go into ultrasonics ? NO !

4. Recording Equipment: Steve pointed out that different quality in reproduction from 96/88.2 kHz and 48/44.1 kHz sampling may result from the non ideal antialiasing filters. Those familiar with DSP will certainly agree that filtering to 20 kHz is easier (and therefore usually better) from 96/88.2 kHz sampling than from the lower frequencies. This may be a reason to master at the higher sample rates. The pay is longer processing time for editing and mastering and the outcome barely audible. Question: Is it worth that effort ? I do not know ! Better to invest more care into the recording situation such as microphone placement

At 20 to 24, when I was working as a part time sound assistant in early TV to earn money for my engineering studies I also recall that all the 15.625 kHz singing from the monitors was annoying.

I remember when both I and television were quite young, I could stand outside a friend's front door and tell from the high frequency whistle whether their TV was on or not - if it was on I would leave without asking if my friend could come out to play!  As I grew older, they seemed to improve TVs so that the noise could no longer be hear.  But of course, it was my ears already going downhill...

Oh, I second that.  I never hear this anymore, but as a kid I also remember being annoyed.  That frequency is still perceivable to me -- if it's loud enough.

By the way, welcome Bert, and interesting to hear your perspective on the matter. 

In a trumpet, it's the body itself resonating that causes the ultrasonic output, not the excitation as such.

I always assumed it was like the human voice: a spectrally-rich puff of air is produced at the source (almost like a triangle wave) of a rather unpleasant tone that is filtered and enhanced along the acoustic path of the sound.  But now that I think of it, listening to a brass player warming up on a mouthpiece alone isn't likely to induce stress from ultrasonic frequency overload -- it's not a bright sound at all.