Hearing above 20Khz & analog consoles.

[drBill]

Originally Posted by Ethan Winer

I agree with that. But only because it keeps the range between 20 Hz and 20 KHz more linear.

--Ethan

Exactly. An that was the initial thrust of this thread before it wandered to the four corners of our globe. Oh wait...the globe doesn't have four corners anymore does it?

[Mike Caffrey]

Originally Posted by paterno

With all due respect, that is a really lame record-making philosophy. It is the utmost responsiblilty of the engineer to do his or her part to get the best performance possible from the artist. The artist is not there doing you a favor, you are there to help them create their recording. If you are not thinking in those terms, it is a disservice to the artist, in my opinion. Would a large group of people buy a record because of it's amazing kick drum sound?...

If it is not going on in front of the microphone, what's the point? No amount of knob turning is going to make it great if it is not great coming from the source. And 99% of the time it is the source where your 'dopamine rush' comes from. If this idea that extended bandwidth= greater pleasure thing is true [which I am not buying], why did recorded music become so popular before the bandwidth we are talking about in this thread even became possible??

As much as I have enjoyed reading this thread and the way it has made me look at what digital recording really is, one of my favorite lines of Dan Lavry has been that he tries to spend an hour a day playing an instrument. Isn't that where the true rush is in all of this -- that feeling we get when playing or listening to something that engages us?

Sorry, not trying to throw things off in another direction.

John

I know exactly what you mean.

When my role has been speeled out to me as an engineer, it's not my job to think, it' my job to listen. Obviously to the sounds, but more importantly to the client or the producer who's taking responsibilit for what's going on infront of the mic.

When people want me to participate in what goes on infront of the mic that's a different story. I'm well away that process affect that regardless of what's been asked of me. But, until someone has either asked me directly or in some way that I've learned that they're asking me to controbute to what goes on infrom of the mic, it's not my place to interfere in their art of the musical content, only the sonic content.

While producing and engineering is an art, it's ultimately a service business and if the service requested is to think about sonics only, I'm proud to think about sonics only.

I've gotten a lot of business where client have said "We asked the last guy to do X and he said no." I always wonder whey they didn't give the same answer when he asked to get paid.

I give 100% of what I can within the parameters that the client has set. That includes asking unmusical, unprofessional, embarrasing quesitons on GearSluts if appropriate.

As for my role in what goes on in front of the mic, that's something that I expect to always keep separate from GearSluts. That's something I love to discuss, but here, I'm only interested in discussing what goes on behind the mic.

[Jules]

Originally Posted by Mike Caffrey

No. Just gnereally disappointed in the moderation in general. Pretty much all I've seen is deleted posts and threads and that's not really moderation.

There's no leadership from th moderators in setting the tone of the board and the moderation (and advertising) are all that sets this apart from R.A.P. This places is feeling a little more liek R.A.P. every month and that's disappointing.

Much of the moderation on GS goes on behind the scenes via PM and emails, so that is inevitably going to be 'invisible'. Feel free to contact me off line via PM with any suggestions you might have for moderation or how the forum might not disappoint you in future.

[JohnRoberts]

Thanks for good Moderation work..

It is surely a handful keeping all these puppies in the pen...

JR

[Kees de Visser]

Did anyone read this article ?
quote from JAES-Sep2007:

Audibility of a CD-Standard A/D/A Loop Inserted into High-Resolution Audio Playback
E. Brad Meyer and David R. Moran 775
Conventional wisdom asserts that the wider bandwidth and dynamic range of SACD and DVD-A make them of audibly higher quality than the CD format. A carefully controlled double-blind test with many experienced listeners showed no ability to hear any differences between formats. High-resolution audio discs were still judged to be of superior quality because sound engineers have more freedom to make them that way. There is no evidence that perceived quality has anything to do with additional resolution or bandwidth.

I'm not an AES member anymore, so don't have access to the full article. Does it add anything new to the (never ending) hi-res audio discussion ?

[muziekschuur]

This thread was initial about high bandwith analog audio and why a clean good console should have an audiopath wich is open up to 100khz. Then we all went digital and Mr Lavry added to the discussion anything above 60khz does not add anything for us mortals.

Because of the nature of PCM audio & DSD there is some Low pass filtering going on in the high frequencies. This damaging proces to audioplayback will have some artifacts in lower frequencies as every note has an note lower to it wich could be damaged aswell.

This filtering is allso going on in DSD playback (read SACD).

Anything in here was about stereo. In nature we people are sensitive for vibrations and phase issues (a stone wich is thrown, hits a wall, changes direction, and could hit your head, so you duck because you sensed it) up to 200khz. So to me 192khz wouldn't be a strange format.

Allthough I can imagine that Mrr Lavry points out such high res content aint happening as 96khz converters are better than 192khz, so essentially there ain't nothing better than 96khz converters at the moment & the rest being marketing hype.

The phase stuff was mentioned in other contexts aswell, but it didn't reflect on "what humans detect" but rather to" what technically is going on in the electronical domain.

Essentially: if someone here is a doctor and can tell us how and if we sense phase with our ears & body in a 3D environment, we could continue this discussion.

If we are talking mono & stereo, essentially the case is closes as phase in a stereo domain is just a relative thing. If phase is something wich does matter, a surround field & High res recording at 96khz will matter and could be something wich would appeal to classical and nature/movie recording and be a minor issue for pop/rock.

I think this is where we are at the moment with this discussion. Thanks all for adding to this discussion.

[Kees de Visser]

Originally Posted by muziekschuur

This thread was initial about high bandwith analog audio and why a clean good console should have an audiopath wich is open up to 100khz. Then we all went digital and Mr Lavry added to the discussion anything above 60khz does not add anything for us mortals.

Because of the nature of PCM audio & DSD there is some Low pass filtering going on in the high frequencies. This damaging proces to audioplayback will have some artifacts in lower frequencies as every note has an note lower to it wich could be damaged aswell.

You seem to say that (any) bandlimiting of a signal is "damaging". Theoretically that's true, that's what the limiting is about, but this AES test couldn't find any indication that bandlimiting to the cd-format (22 kHz?) is audible.
I thought it would be appropriate to mention the test here since it is similar to the one Ethan proposed earlier in this thread: insert a low-pass filter in a high bandwidth signal and check if there is an audible difference.
You seem to distinguish between analog and digital audio. Both are characterized by their bandwidth and noise. There is no fundamental difference. Digital audio is only audible after it has been converted to analog (DAC).
IMO to have a clean passband (audible range up to say 20 kHz), a (steep) digital filter allows for a smaller bandwidth than analogue circuitry which usually doesn't have steep bandlimiting filters.

[Blinddot]

Sorry for not reading the whole thread, but I'd like to link this old thread, the last post is mine, and I left on it a few links which I consider interesting ones about the subject..

hope you find it interesting

Does frequency response ABOVE 20 kHz really matter?


saludos

[themaidsroom]

i think there is much information beyond 20k that gives us our spatial
conception of sound. i have never heard a digital recording convey depth.
i have sat with some of the most esoteric dsd sytems and still found
the 1" 8 track from 1966 infinitely more hifi than the sacd it is becoming
- more than anything the
analog is the only medium that conveyed space and depth to me -
is there a scientific
scale for this factor ? my friend walter sear said simply the line i started this
post with - there is much information beyond 20k that gives us our spatial
conception of sound.
i work with both mediums every day for five years. 2" 16 track is magic.
2" 16 track is magic with tape that is 12 years old. digital is always a
compromise in my opinion. i am buying a second A827 so none of my
overdubs will have to be in pro tools any more. it has been heartbreaking
to hear beautiful percussion overdubs by amazing nyc players rendered
flat the minute they are converted.....

i wonder if any digital medium will have such support when it is approaching
its 40th birthday ?


be well


- jack

[muziekschuur]

I've seen such a test a while ago. Done by students. They used speakers wich were from the nineties wich are unreliable in the high. Who knows how high their response goes?

[Kees de Visser]

I think it's a fair requirement for a transparent audio system to have an amplitude/frequency response drop of no more than 0.1 dB at 20 kHz.
Thanks to their steep low-pass filters, digital systems don't need to have the -3 dB point (common definition of bandwidth) much higher than that. Analog systems have much less steep low-pass filtering, hence need more (-3dB) bandwidth to achieve transparency. I'm not sure if 100 kHz is really necessary, but 25 kHz might not be enough, especially when cascading many devices (like in large mixing consoles).

Just my €0,02

[Ethan Winer]

Originally Posted by Kees de Visser

25 kHz might not be enough, especially when cascading many devices (like in large mixing consoles).

That's a great point. It's not enough for each component to be flat out to 20 KHz. When multiple components are in series the total signal path must be flat to past what is audible.

--Ethan

[Kees de Visser]

Since I can't do the math myself, I decided to ask Bruno Putzeys, a highly respected EE engineer, to give some examples of bandwidths (-3dB ref) required to achieve -0.1 dB at 20 kHz in analogue equipment.
His reply:

For a butterworth roll-off of a given order, 0.1dB attenuation at 20kHz:

1st order -> 131kHz
2nd order -> 51kHz
3rd order -> 37kHz
nth order -> 20kHz*6.552^(1/n)

As the filter gets steeper and steeper, the corner frequency inches closer to 20kHz. Of course, at some point it's phase shift at 20kHz that starts becoming the dominant factor. Besides, 131kHz is already so low you'd need to roll off the circuit intentionally to get there.

I don't know if it's ok to assume butterworth roll-off, but this seems to nicely illustrate that analogue equipment needs quite a large bandwidth (-3dB) to guarantee a flat response (-0.1dB) in the audible range.
A (near) perfect digital system only needs about 22 kHz bandwidth to give the same response.
Neve and Nyquist, perhaps not that different after all ?

[WidgetNinja]

Originally Posted by muziekschuur

Anything in here was about stereo. In nature we people are sensitive for vibrations and phase issues (a stone wich is thrown, hits a wall, changes direction, and could hit your head, so you duck because you sensed it) up to 200khz. So to me 192khz wouldn't be a strange format.

<snip>
The phase stuff was mentioned in other contexts aswell, but it didn't reflect on "what humans detect" but rather to" what technically is going on in the electronical domain.

Essentially: if someone here is a doctor and can tell us how and if we sense phase with our ears & body in a 3D environment, we could continue this discussion.

Yay! Someone else that feels like me. Brains move very fast. Since we can realize phase, it seems that there is a good deal of information we "hear", but don't consciously process, the same way we can feel one thread on our skin, but presented with a shirt our brain doesn't attempt to feel thousands at once. If there was sound moving like a particle, and our little sensors could vibrate at one frequency, we could still infer others so long as we have at least 2 sensors. Likewise we infer position all the time, despite the sound coming in at different angles. Crazier still, we can do it with one ear. To do the same with sensors we need three so front and back or elevation is distinct. Waves just make the information pool even bigger.

[drBill]

Originally Posted by Kees de Visser

Since I can't do the math myself, I decided to ask Bruno Putzeys, a highly respected EE engineer, to give some examples of bandwidths (-3dB ref) required to achieve -0.1 dB at 20 kHz in analogue equipment.
His reply:
I don't know if it's ok to assume butterworth roll-off, but this seems to nicely illustrate that analogue equipment needs quite a large bandwidth (-3dB) to guarantee a flat response (-0.1dB) in the audible range.
A (near) perfect digital system only needs about 22 kHz bandwidth to give the same response.
Neve and Nyquist, perhaps not that different after all ?

Kees, well......you hit the proverbial nail on the head. That's what this thread was all about. However, like most threads on the internet, it took on a life of it's own and careened off in numerous tangents. Thanks for the specs.

[2 trak]

I dont want to sound basic but surely neither systems are perfect. What we are battling against with analogue is obviously noise, and digital its distortion and alias filters.

Digital consoles sucked for my music.

Hearing over 20KHz is a silly suggestion. Unless there is some other resonating body in the head picking things up. I have no explanation as yet why the wave changes from a 12 kHz sine to a square and we can still percieve that 2nd harmonic. I should read up on my notes but this I think has been a long standing issue. Nothing to throw to the masses in a pitch to sell analogue desks. I recon analogue desks and cheap digital desks are a load of old hat. Analogue circuitry needs to be re-organised and the tranditions dropped if we are to explore it further.

Oh shit yeah.. Phase right!

[Ethan Winer]

Originally Posted by 2 trak

I have no explanation as yet why the wave changes from a 12 kHz sine to a square and we can still percieve that 2nd harmonic.

This was explained somewhere in one of the past bunch of pages. When you switch between a square wave and a sine wave in a signal generator, the RMS volume level changes at the fundamental frequency. So that's why it sounds different.

--Ethan

[lucey]

Originally Posted by drBill

No problem here Jules! I'm good with that. thumbsup



bp

Nice post on L and R brain.

Ideally a balance ... but rarely!