PONO

[Davo]

There is life above 20 KHz.
http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

I don't think anyone would argue that instruments emit frequencies above 20kHz. At least no one in this thread seemed to.

I'm just following the signal path, starting with pressure waves in the air. Some tweeters can reproduce frequencies up to 100 KHz.

[stringtapper]

There is life above 20 KHz.
http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

I don't think anyone would argue that instruments emit frequencies above 20kHz. At least no one in this thread seemed to.

I'm just following the signal path, starting with pressure waves in the air. Some tweeters can reproduce frequencies up to 100 KHz.

Sure, we can imagine an ideal testing environment. You're finding some frequency responses I haven't been able to find. Cool.

But it still doesn't get at the key problem in all of this: how ultrasonic frequencies are (or aren't) impacting the audible range in a way that can be perceived as an improvement over not having the ultrasonic frequencies present.

[H20nly]

i joked about it earlier.... but seriously... how can these frequencies be put back in the music?

i get it that these frequencies could have an impact during the initial recording, mixing, and mixdown that does have a meaningful affect despite being inaudable, but once those frequencies are exported or processed out... how can they be mastered back in? that doesn't make a lick of sense to me. it's like trying to glue hair back on after a hair cut... just not the same. i can see cleaning up elements such as hiss or muddiness, raising the volume levels, and fine tuning the EQ, but putting back something that was lost at the press or during the transfers seems implausible. having access to the original masters used for vinyl, cassette, or CD production might be a step in frequency retrieval process, but that seems like a step backward - yeah, let's give Sony, Columbia, Virgin et al one more reason to milk the rights and flex ownership of the catalogue of damn near every artist prior to 2005ish and just most beyond.

as far as PONO the player goes... what would be a cool twist is if it delivered ease of use (not acting like an overly possessive pimp with your music like iTunes does), hi quality format support (any current format), AND if it was reasonably/respectably priced for all of the pain it removes and hi quality sound and the smooth loading/unloading of music it delivers (say 100 - 160 dollar range). iPods were/are expensive... even more so now considering that our smart phones will do the same and a shit ton more - and we already carry those... many more of us carry them now than when iPods first hit the market (flip phone era). with smart phones going from business to consumer hands it seems to cut out this niche player market beyond at the gym/running/cycling. whipping out a PONO loaded with hi quality sounding recordings and plugging it into an audio input on a stereo somewhere (car, home, friends house) seems like it would have some merit if someone could afford to do it. but using a hi-fidelity player with bullshit earbuds cancels out the end result (as mentioned earlier in the thread). using one with Beats By Dre type headphones at PONO's current pricing *scheme* means that you're literally carrying almost 1000 bucks in audio equipment on you. seems like a recipe for getting mugged... and oh, by the way... the music is then colored by the Beats algorithm and we're back to not having music exactly as the artist intended... but rather how Dre sets his 12 band EQ in one of his 6-fo Impalas.

[Davo]

But it still doesn't get at the key problem in all of this: how ultrasonic frequencies are (or aren't) impacting the audible range in a way that can be perceived as an improvement over not having the ultrasonic frequencies present.

Is that they"key problem"? I said how ultrasonic waves might modulate sonic ones. You also had concerns about inter-modulation distortion. That will only be present in the non-linear parts of the system. We know that some microphones are fairly linear up to quite a high frequency. Any inter-modulation distortion will presumably be well outside of the audible range (where the system components become less linear).Maybe slightly distorted hyper-sonic energy is better that no energy at all?

It might be a bit off topic, but apparently modulated hyper-sonic audio is hyper-directional and can be made to generate audible frequencies. http://en.wikipedia.org/wiki/Sound_from_ultrasound.

[re:dream]

It all reminds me a bit of

[fishmonkey]

the few experimental studies that have been done on ultrasonic frequencies suggest that we can perceive them in some circumstances, however it is through bone conductance, not our ear drums...

another important question would be what ultrasonic frequencies are actually preserved after conventional audio tools are used in the recording and production process...

[Davo]

the few experimental studies that have been done on ultrasonic frequencies suggest that we can perceive them in some circumstances, however it is through bone conductance, not our ear drums...

another important question would be what ultrasonic frequencies are actually preserved after conventional audio tools are used in the recording and production process...

If you follow the signal path thrgh it seems that there is some possiblity of preservation. Pono might need a good driver configuration for accurate reproduction, possibly in-ear might be best. Bone conduction might be important but there is also a possiblity of untrasonic modulation of sonic freequencies, and possibly some additionial directional (positional, spatial) information in the hypersonic range.

[Forge.]

and a glass of water

one of the few forum elders old enough to appreciate that reference.

[Forge.]

I taught a class recently where I used the test tone in Ableton right up to 20k to see who could hear it. Over about 14k I was pretty much out of the game, some of the younger ones showed some discomfort when I went higher and cranked the volume WAY up.

Point being... music is about using sound to convey feeling and emotion. The vast bulk of that is going to happen within the main range of hearing we are all most sensitive to.

There is probably little real feeling going to be stirred up above 10k.. let alone 15.. 20... anything above that is just a waste of time and energy in *real* terms.

the vast bulk of the shit that really pushes our buttons is probably between around 50 Hz and 5000Hz. If you are at a gig with cheap foam ear plugs in and Bob marley is on stage, almost everything you need from that experience will be within that range. Some other shit between 5 and 15k might give it a slight sense of sweetness.. but after a few rum and cokes and spliffs you are not going to give the slightest fuck about any of it

bass that you can feel, groove you can feel, melody and lyrics that mean something to you.... perspective

listening at home on high end gear sometimes this shit might matter... but it rarely matters to me. The things I want from the music I listen to aren't usually that kind of wanky shit.

we have better things to do with our time

[HorusProject]

Some information on "high resolution" audio from Mr Ethan Winer

"The lack of benefits of "hi-res" audio are well known.

Both of my AES workshops, and the resulting videos I made, explain why 44.1 KHz is sufficient:

http://www.youtube.com/watch?v=BYTlN6wjcvQ
http://www.youtube.com/watch?v=Zvireu2SGZM

There are several published accounts of people not being able to tell when a 44/16 "bottleneck" was inserted into a hi-res playback path. Meyer & Moran's tested 60 people over a period of one year in 554 separate trials, and the results showed that statistically nobody was able to tell the difference:

http://www.aes.org/e-lib/browse.cfm?elib=14195

This article explains some of the reasons people might believe they hear an improvement when none exists:

http://www.ethanwiner.com/perception.htm

And of course my Audio Expert book explains in much more detail:

http://www.ethanwiner.com/book.htm

This is probably more than you asked for! "

Cheers,

[stringtapper]

Hey thanks for all of that! I had a feeling Winer would come up in all of this.

[stringtapper]

Some tweeters can reproduce frequencies up to 100 KHz.

Can you give an example of one? Thanks.

[stringtapper]

Well after reading many articles and online discussions and having some correspondence with Ethan Winer (who is a really nice guy!) I think I've come down on the "hi-res is bullshit" side of the argument.

On intermodulation distortion: This is a result of non-linearities within a sound system. In other words this isn't a part of the actual sound that needs to be preserved by using high sample rates but rather an artifact of the equipment in the audio chain such as amplifiers and speakers. Once again for clarity: The ultrasonic frequencies going on around us in the air are not causing intermodulation distortion by interacting with frequencies in the audible range. It's something that happens after the sound has been captured and is in the system.

Intermodulation distortion can occur in our ears though. It happens when sound sources become very loud and distort creating a psychoacoustic effect that we perceive as combination tones.

Ethan Winer describes it well in his book:

Even though few people can hear frequencies above 20 KHz, we can sometimes be affected by those frequencies. This is not because of bone conduction or other means of perception, as is sometimes claimed. It's because our ears are nonlinear, especially at loud volumes. As explained in the previous chapters, whenever an audio pathway is nonlinear, sum and difference frequencies are created.

One of my favorite examples derives from when I played percussion in a local symphony. A glockenspiel is similar to a vibraphone but smaller, and the metal bars are higher pitched and have no resonating tubes underneath. A glockenspiel can also play very loud! I noticed while playing a chord of two high notes that I heard difference frequencies as overtones when those notes aliased down into the audible range. That is, I'd hear low tones even though both of the notes were very high pitched. But the distortion was created entirely within my ears.

It's not that my ears are defective; anyone can hear this. But you have to be very close to the glockenspiel in order for the volume to be loud enough to distort your ears. I've never noticed this from out in the audience. You can even hear IM products from a single note because the various supersonic overtones of one note can create audible sum and difference frequencies. Unlike square waves, the overtones from bell-type instruments are not necessarily harmonically related. It's possible for a very high note to contain ultrasonic overtones closer together than the fundamental frequency. If one harmonic is 22 KHz and another is 25 KHz, the result is the perception of a 3 KHz tone.

So it's possible to be influenced by ultrasonic content, but only because the IM tones are generated inside your ear. Further, I don't want to hear that when I'm listening to a recording of my favorite music. If a recording filters out ultrasonic content that would have created inharmonic distortion inside my ears at loud volumes, I consider that a feature!

[re:dream]

But...

[fishmonkey]

Intermodulation distortion can occur in our ears though. It happens when sound sources become very loud and distort creating a psychoacoustic effect that we perceive as combination tones.

Ethan Winer describes it well in his book:

distortion products in our ears are a well-known phenomenon. i don't think that is the end of the story, as Ethan is suggesting. based on the research that has been done, i think he is wrong about bone conduction, for example (and associated references):

http://www.ncbi.nlm.nih.gov/pubmed/23384569