88.2kHz?

[hummingbird]

okay.... I officially can't read this thread anymore

[Casey H]

Quote:Quote:If this weren't the case, then why would anyone notice an improvement in sound at higher sampling rates?The argument of the people who say you can't hear (or "sense") beyond 20k is that the steepness of the filters designed to keep out all frequencies above 22.05k (which are required to keep the converters working properly) are actually having effects down into the audible range. When you use 88.2, you can have a much more gentle filter design which doesn't mess up any of the signal in the audible frequency range. Thus, it sounds better. So the claim is you can't hear additional harmonics beyond 20k when you listen to 88.2 or 96, but what you hear is the absence of artifacts in the audible range which are present in 44.1 and 48 recordings. This is not entirely preposterous I think, after all the difference going to higher sample rates is rather subtle when compared to the difference you hear going from 16 to 24bit.I'm not saying this is true and the idea we can somehow sense beyond 20k is BS, but as far as I know there is no scientific proof for the latter.So here I am defending science to a math wiz...ah the irony. Wow, could this become the next "Sgt. Pepper" or "Music Trivia Jeopardy" thread? First, Vikki... Cyber-Advil comin' at ya... Math wiz? nah... Just someone who likes to try to explain complicated engineering things in layman's terms. I work with a lot of mega-nerdy engineering types (yes, more nerdy than me ) who have trouble "dumbing things down". As you can see, it isn't easy, especially with an audience that is at so many different levels. (How did they ever do all that teaching in ONE little schoolhouse years ago?) One of my goals for the next year is to publish one or two short articles, explaining some things in my industry in simple terms, ones that maybe the non-engineers (marketing, purchasing, management, etc) can relate to without too much techo-speak. Yesterday I was at a meeting with engineering and an ad agency and watched their eyes glaze over when one of my fellow engineers (a genius and great guy BTW) would speak. (Our products are better because we use 14-bit A/D and they all use 12!!! ....Yes, but does our intended audience care about THAT?)What you said about the steep filtering is entirely correct. But, in pure theory, even without any filtering, lower sample rates mean missing higher frequencies. In the highly exaggerated, silly example I gave earlier in the thread, I mentioned how if something happens in between samples, it is missed. Higher frequency components happen faster, hence they can be missed. So, at the "dummies" level it explains a lot. That, of course, has nothing to do with whether or not the human ear gives a darn about sounds over 20KHz.For anyone who hasn't already stopped reading or took a migraine pill and went to bed, what is this "steep filtering" thing that Matt referred to?A filter is a device which allows certain frequencies to pass through it and others not. The cutoff(s) can be at the low-end, the high-end, or both. Some have gradual cutoffs, kind of like a fade-out ending... e.g. a gradual decline of what is passed through as frequency changes. "18 KHz, you can come in, but only at 1/2 size, 19 KHz at 1/4 size", etc... Others have very steep or sudden cutoffs such as "under 20 KHz you are in, over 20 KHz you are out". When signals such as audio are converted to digital, it is necessary to steeply filter out anything above 1/2 the sampling frequency rate. This prevents what is known as "aliasing", very simply put, high frequency values that would cause distortion if allowed through. But a filter doesn't know a high frequency noise spike from something that might actually be good for the music. With 44.1KHz sampling, as Matto mentioned, they steeply filter out anything above 22.05 KHz. Higher sampling rates mean the filter cutoff frequency can be higher such as 44.1KHz for 88.2KHz sampling. There is also talk of "phase shift" changes that these higher frequency values create which add to the natural quality of the music. Some argue that filtering out these phase effects diminishes the quality of the music. Although I am not sure in exactly what context these phase shift changes in music are, in general, phase just refers to the timed relation between two components, similar to: happening at the same time as desired vs. one thing happening at a different time than the other. Pure audiophiles maintain they can here these subtle differences. I know I still can't differentiate the sound of my mp3s (especially at 192K+) from my master .wav files. But I don't have audio engineer ears. I work with a 60 year old die-hard audiophile who listens only to classical music. He claims he hears all these things and can tell the differences. I have my doubts, especially at the age of 60. I've been promising to bring him the same music sample as 128K mp3, 192K mp3, and standard 44.1K wav and ask him if he can blindly pick which one is which. He says he will bring in his super-duper headphones for the challenge.Matt, I don't think there is any scientific evidence that we perceive frequency components over 20k. There is anecdotal evidence only. I can't imagine that no double-blind controlled studies have never been done?I'm glad I'm into rock music... At the end of the day I can quote Jagger and say, "It's only rock n' roll..." Casey

[ernstinen]

Quote:okay.... I officially can't read this thread anymore Hang in there, Hummin'bird! I don't understand it either, but I'm trying. All I know is that I can SENSE sounds above 26 kHz. Maybe I've just got good ears.Here's a current photo my wife took of me:**************************Ern

[rcase]

NOW I understand why Ern's avatar is so blurry! You shouldn't try to hide them, Ern. You know what they say about men with big ears..

[johnnydean1]

Quote:Quote:okay.... I officially can't read this thread anymore Hang in there, Hummin'bird! I don't understand it either, but I'm trying. All I know is that I can SENSE sounds above 26 kHz. Maybe I've just got good ears.Here's a current photo my wife took of me:**************************Ern You get better with age Ern.

[Casey H]

Quote:Here's a current photo my wife took of me:Ern Ern,Are you coming to the rally? Do you have to buy a second plane ticket for your ears? Casey

[andreh]

Quote:Quote:If this weren't the case, then why would anyone notice an improvement in sound at higher sampling rates?The argument of the people who say you can't hear (or "sense") beyond 20k is that the steepness of the filters designed to keep out all frequencies above 22.05k (which are required to keep the converters working properly) are actually having effects down into the audible range. When you use 88.2, you can have a much more gentle filter design which doesn't mess up any of the signal in the audible frequency range. Thus, it sounds better. So the claim is you can't hear additional harmonics beyond 20k when you listen to 88.2 or 96, but what you hear is the absence of artifacts in the audible range which are present in 44.1 and 48 recordings. This is not entirely preposterous I think, after all the difference going to higher sample rates is rather subtle when compared to the difference you hear going from 16 to 24bit.I'm not saying this is true and the idea we can somehow sense beyond 20k is BS, but as far as I know there is no scientific proof for the latter.Ah yes, I forgot about the old brickwall filter...its steepness and position could certainly be affecting the sound as well. Andre

[elser]

Quote:Quote:Just wondering who's recording at 88.2kHz or better and how much better do you think it sounds. I've got these ancient converters that don't go above 48kHz and wondering if I need to upgrade. Thanks, ElserElser-IMO, your decision to upgrade should be based on the quality of your 48k convertors compared to the quality of the 88.2/96k convertors you might replace them with - there's a lot more to how a convertor sounds than just the math its chips employ.For example, if you're considering dropping your Apogee Rosetta DA/AD pair that tops out at 48k in favor of a Sound Blaster X-Fi Elite Pro that goes up to 192k, you're probably making a bad move...the noisier circuitry of the Sound Blaster would certainly cancel out any benefit you'd get from its higher sample rates.OTOH, if you're stepping up from an earlier M-Audio Flying Cow 16/48 to, say, one of the newer (or even made within the past 5 years) RME boxes, you're going to hear a noticeable difference in sound - even at "lower" sampling rates such as 44.1 or 48k.To cut through all the technobabble re: recording at high sample rates, if you're doing live (not reproduced through a sampler/computer) acoustic or orchestral music, you may hear a difference in sound quality that justifies 88.2k (destined for CD) or 96k (destined for film/video) recording rates. Otherwise, a good-quality convertor running at 44.1 or 48k can generate excellent results.HTH,AndreSidenote - The Apogee Rosetta series is actually upgradeable to 88.1/96k performance, but for the sake of making my point I left that little factoid out. Andre, hey thanks for that. My converters are Swissonic, wonder if anyone else remembers 'em. At the time they came out the tech specs were better than the current offering by MOTU and I couldn't afford Apogee or Protools so they've served me well. My feeling at the beginning of this thread was just sort of an intuitive sense that there must be a digital answer to the complaints that people have of analog vs. digital. I've followed the math as much as I can and believe that these kinds of discussions are the type of thing that help to move the technology forward. It seems to me, again on an intuitive level that the quality at which upper harmonics are recorded, regardless of whether we actually hear those frequencies or not, must affect the overall impression we get of the sounds we record. But then I believed in Santa till I was about 10. Elser

[andreh]

Elser-I remember the Swissonics convertors getting some respect in their time, and a few quick web searches verify their performance. OTOH, convertors of all price ranges have seen a significant bump in sonic qualify over the past 5-7 years since Swissonics' heyday, so it might be worth your time to sample the latest bunch.Speaking of which, here's a way to do so without having to buy loads of gear yourself for a comparison:http://www.3daudioinc.com/catalog/produ ... 13fc58This CD is several years old now so it may not be of much help; I hope its creator is in the process of updating it soon!André