Quote dmills:

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Stratt,
Mixing has two different meanings!

In audio, it typically means summing (which produces no new sidebands), in most other electronics it means multiplication which obviously does produce new components.

I think you are confusing the two meanings of the word 'mixer'!

Regards, Dan.

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I take your point about sidebands but summing two separately recorded (at 96kHz) instruments that can produce ultrasonic harmonics can result in a sonic subharmonic (beat frequency) can't it? But when recording at 44kHz the required bandlimitation of 22kHz will filter out any of the instruments ultrasonic harmonics and the sonic subharmonic will not be produced.

I'm just thinking that the jury's still out on whether recording original material at 96kHz offers no sonic advantages over 44kHz.

Stratt

I don't understand why the inaudible frequencies picked up by the 96khz sampler would be any more likely to create beat frequencies than those within the 0 - 20khz range of the 44.1khz sampler.

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Anto mo Ninja, Watashi mo Ninja

So called 'sub-harmonic' generated by the beating of two closely spaced frequency signals is a red herring.

The sub-harmonics are not really there. They are a product of how our ears interpret the intermodulation of the signals. You cannot filter out or isolate the sub harmonics, and if you remove one of the signals, the sub harmonics disappear as well.

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Nik
Godin, Axon, Tonelab, Repeater & the skin of my teeth!

Quote molecular:

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I'm no expert on this, but the two types of bat common up here are identified with a detector that pitch shifts their echo-location signals. As far as I can remember, the species are identified by audio at around 40khz and 60khz respectively.

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They are fun boxes to play with. Try pointing one at your laptop screen and/or power supplies for starters... and then have a wander through the house turning things on and off to see how much spurious ultrasonic shash there is that you are unaware of.

And then think really carefully about buying loudspeakers with supertweeters that give them a flat response to 50kHz, or Earthworks microphones flat to 40kHZ!

hugh

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Technical Editor, Sound On Sound

Hello Hugh!

Do you know of any studies that have been conducted on the effects of these supersonic frequencies on people? I know I've woken up agitated the moment people have turned on a CRT telly, but that's hardly bat territory... I just wonder if there's some harder to quantify effect of these things that perhaps people aren't conscious of?

Cheers!

Chris

Quote Stratt:

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Am I wrong?

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No, Stratt, you are quite right. I think the confusion is because one of the participants here had a bee in his bonnet about the effect of the filters on frequwncy conponents very close to the turn over frequency, comnbined with some misunderstood notions about the sampling requirements. Hopefully all resolved now.

hugh

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Technical Editor, Sound On Sound

Quote molecular:

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I don't understand why the inaudible frequencies picked up by the 96khz sampler would be any more likely to create beat frequencies than those within the 0 - 20khz range of the 44.1khz sampler.

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I think the point being made here is that a lot of instruments generate ultrasonic components. In real life, these UHF components will interact with each other because of inherent non-linearities in the instruments, the air and our ears.

If you record instruments individually with a 96kHz sample rate, and processes the mix with similarly specified equipment, those ultrasonic components can be preserved, and they can interact with each other again either when the signal is reproduced, or because of some non-linearities inthe processing equipment.

If you record at a base sample rate, those ultrasonic signals will be removed at source, and there potential for interaction will be lost.

There are many that argue -- and I can seee some logic in this argument -- that this is one possible reason why it is so hard to make brass band recordings that sound like a live brass band, and why close miking individual violins and mixing them together sounds very little like a more distant mic capturing an entire violin section.

hugh

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Technical Editor, Sound On Sound

Quote Korff:

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Do you know of any studies that have been conducted on the effects of these supersonic frequencies on people?

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hi Chris. Yes, There have been several studies, but as far as I know nothing really substantiated. I believe I've read some reports in the AES journals in the past (a Japanese one sticks in my mind, but I think that was because it has been discredited), and in the Journals of the Institute of Acoustics. I can't give you any specific links, but if you serach the websites of those two organisations I'm sure you'll find something of interest.

I think this has also been discussed in one of the standard texts concerning human audiology -- Brian Moore's Introduction to the Psychology of Hearing -- although it's been a while since I read that and I can't reach it on my bookcase right now because of a huge mountain of unfinished work that I must get down before I can go on holiday

hugh

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Technical Editor, Sound On Sound

Not sure about supersonic frequencies but there was this myth floating around that some subsonic frequencies could loosen the human bowels.

Sorry,

Am I in the right thread?

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I'm All Ears.

Quote Ken Long:

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Not sure about supersonic frequencies but there was this myth floating around that some subsonic frequencies could loosen the human bowels.

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Ah, the mythical brown note ...

It's not mythical!

Hugh

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Technical Editor, Sound On Sound

Quote Korff:

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Hello Hugh!

Do you know of any studies that have been conducted on the effects of these supersonic frequencies on people? I know I've woken up agitated the moment people have turned on a CRT telly, but that's hardly bat territory... I just wonder if there's some harder to quantify effect of these things that perhaps people aren't conscious of?

Cheers!

Chris

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CRT's emit an audible hiss... particularly when you turn them on or off. Hit the "Degauss" button on one and you'll hear it.

CRTs often emit a high-frequency whine / whistle at the horizontal scan frequency which I seem to remember is around 16Khz for a UK TV but will be higher for a monitor with high resolution or high vertical refresh rate.

I *used* to be able to hear it, but those days are gone.

Edited by markhodges (09/07/08 07:39 AM)

Quote Hugh Robjohns:

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If you record instruments individually with a 96kHz sample rate, and processes the mix with similarly specified equipment, those ultrasonic components can be preserved, and they can interact with each other again either when the signal is reproduced, or because of some non-linearities inthe processing equipment.

If you record at a base sample rate, those ultrasonic signals will be removed at source, and there potential for interaction will be lost.

There are many that argue -- and I can seee some logic in this argument -- that this is one possible reason why it is so hard to make brass band recordings that sound like a live brass band, and why close miking individual violins and mixing them together sounds very little like a more distant mic capturing an entire violin section.

hugh

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Sorry, yes. - I had thought the post was saying that in some circumstances 44.1 would be *better* than 96, as it would disallow such audible interference.

H

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Anto mo Ninja, Watashi mo Ninja

Quote Interweaved:

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CRT's emit an audible hiss... particularly when you turn them on or off. Hit the "Degauss" button on one and you'll hear it.

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I think he was referring to the line scan whistle which in the case of a PAL TV is at 15.625kHz.

Hugh

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Technical Editor, Sound On Sound

Quote Hugh Robjohns:

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I think he was referring to the line scan whistle which in the case of a PAL TV is at 15.625kHz.

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Many years ago when I could hear this, it annoyed me.
Now I can't hear it, it annoys me even more!

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Cubase, guitars.

Going back to the original question. I was considering this myself whether to start a new project at 96 or 44.1 and someone on the mastering forum said that some cheaper converters sound better at 44.1 than 96 so it is worth doing a quick A/B. I did this using my Brauner phantom se mic into a dav preamp and then into my RME Fireface 800 interface. Monitoring via PMC TB2+ sa speakers. I recorded a solo voice and there was an instantly noticeable difference between the 2 recordings I made. 96 sounded less grainy and more natural. I also put a little LA2A and plate 140 from my UAD card on both the 96 version still sounding noticeably smoother. I was kind of hoping it wouldn't be so as I have only one UAD1 and may have to get another now or use less plugins! I reckon if you were going to do a full on Rock or Pop production the difference may or may not be noticeable or 44.1 may be more appropriate for the sound you are trying to achieve. The point is it is worth doing a very quick A/B with your own setup especially if you are going to have your project mastered by someone with high end gear because I reckon most of the benefits will filter down to the production CD at 44.1.

Quote ESE:

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The point is it is worth doing a very quick A/B with your own setup especially if you are going to have your project mastered by someone with high end gear because I reckon most of the benefits will filter down to the production CD at 44.1.

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You should do a blind test. Then you have proved something. And you'll probably be surprised by the results.

Quote Nuno_:

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Quote ESE:

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The point is it is worth doing a very quick A/B with your own setup especially if you are going to have your project mastered by someone with high end gear because I reckon most of the benefits will filter down to the production CD at 44.1.

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You should do a blind test. Then you have proved something. And you'll probably be surprised by the results.

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In my setup the difference wasn't that subtle at all to require deliberation and going back and forth. The vocalist instantly noticed the difference too. There were clear sonic differences. Whether it will filter down to making a difference on a production CD at 44.1 I can only guess but I think it probably will. Particularly I would guess on open sounding acoustic material. The point is it is worth doing a test to see if there is a difference in your own particular setup and which sound you prefer. If you can't hear any differences stick with 44.1 I'd guess.

Quote ESE:

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Quote Nuno_:

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Quote ESE:

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The point is it is worth doing a very quick A/B with your own setup especially if you are going to have your project mastered by someone with high end gear because I reckon most of the benefits will filter down to the production CD at 44.1.

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You should do a blind test. Then you have proved something. And you'll probably be surprised by the results.

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In my setup the difference wasn't that subtle at all to require deliberation and going back and forth. The vocalist instantly noticed the difference too. There were clear sonic differences. Whether it will filter down to making a difference on a production CD at 44.1 I can only guess but I think it probably will. Particularly I would guess on open sounding acoustic material. The point is it is worth doing a test to see if there is a difference in your own particular setup and which sound you prefer. If you can't hear any differences stick with 44.1 I'd guess.

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I am not saying that you didn't hear a difference, or that there was no difference to be heard. What I mean is that without a blind test your perception is influenced by your beliefs, and thus it's not in any way objective. As you probably know, it is called the placebo effect. By doing a blind test you remove it from the equation and then we can then know that you heard a difference, instead of knowing that you think you heard a difference.

If the difference is that obvious, then you should have no problem identifying it 100% of the time and then you'd have proven that you can actually hear the difference.

Anyway, it reminds me of those funny high end people at gearslutz that always categorically affirm things like that an apogee definitely sounds better than a RME, and many tested them side by side and heard obvious differences. Yet, when someone posted wave files recorded trough both units without disclosing which was which, most picked the RME as sounding better.

Needless to say since most people contradicted themselves and were a bit embarrassed by the result, I haven't seen a blind test there since. For some reason every poster seems opposed to them.