What are the ACTUAL specs for the 828 MKIII?

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Discussion related to installation, configuration and use of MOTU hardware such as MIDI interfaces, audio interfaces, etc. for Mac OSX
singproinc
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Post by singproinc »

The answers to your questions are contained in the above mentioned white paper. It's a well-researched, factual work, from a highly respected engineer who is rooted in both theory and practice, music and engineering.

I suggest you read it and see if it answers your questions. Not only are sample rate issues addressed, but many other contributing factors that affect how we perceive and process sound, both as biological entities and with our equipment, are addressed and integrated.

You'll find the answer to your question, for example, "why do people relate the sample rate as being the frequency response." and a thorough discussion of sampled waveforms, harmonics, the limits of physics, biology and manufacturing, plus much more. You are using the vocabulary, so you should be able to grasp the meaning of Dan's research.
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monkey man
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Post by monkey man »

thashobs wrote:How do we strive to make digital gear as good as analog? higher sample rates..... new products coming in the next few years include 32-bit 256k sample rates. pro tools as well as all daws will have this.
Agreed.
thashobs wrote:can you hear a difference between an mp3 at 128k vs. 320k if you answered no than your probably over 30 or are almost deaf.
Ha! I'm well over 30 and slightly deaf, but it's still obvious. No argument there.
thashobs wrote:why do people relate the sample rate as being the frequency response. if you say you cant hear a difference between 192k and 44:1 sample rate your an idiot. First the 192k means that the song is sampled 192 thousand times per second 44.1 is only 44 thousand times per second. If you were to draw an analog waveform it would be perfectly curved. A digital waveform under the microscope looks like jagged stairs. the number of jagged edges depends on the sample rate. the higher the sample rate the smoother the digital representation of the analog waveform.
Well, there are other real-world factors that come into play, thashobs, such as speaker/headphone responses and output circuitry/DA converters. D/A converters, for instance, attempt to smooth those stair steps you refer to out. Some do an apparently amazing job of this, which is why a decent "20k" system can conceivably sound better than a much-higher-rated one. MOTU's own interfaces have shown this over the years. I heard that, for some users at least, the 44.1k setting on a certain interface (I've forgotten which one) sounded better to most ears than the 88.2 one.

thashobs wrote:this is why analog sounds so much better. also analogs comparative sample rate of analog gear would be infinite(yes infinity)
Correct, it is one of the main reasons why this is so for many folks. I'd like to point out though that the resolution of analog is not infinite. Measurements of time, distance and mass are subject to Planck length minimums (usually a metre, gram or second to around 10 to the minus 34th+ power), and are effectively quantized, but so fine is this quantisation that science didn't discover it 'till the 20th century:

From the link below: "Combined, these two theories imply that it is impossible to measure position to a precision shorter than the Planck length, or duration to a precision to a shorter time interval than a Planck time."

http://en.wikipedia.org/wiki/Planck_length

A heavier overview of Planck units:

http://en.wikipedia.org/wiki/Planck_units

From this link below: "This is the ‘quantum of time’, the smallest measurement of time that has any meaning, and is equal to 10-43 seconds. No smaller division of time has any meaning."

http://www.physlink.com/Education/AskEx ... N=77617356

This phenomenon is why I sometimes say we're living in a digital simulation. Even DNA code is digitally defined (mess up a single value and a larger, more-encompassing description is likely to become corrupt).

Sorry. Thought you might appreciate that. At any rate your point is still valid, given the vast difference between what we perceive as analog and what we know as digital. I've always been a fan of Sony's bitstream technology, which I think samples at over 300MHz, for this very reason. It's as if Sony saw the writing on the wall and said, "Let's just nip this bitrate war in the bud".
thashobs wrote:the reason for can hear a difference in sample rates is because even though we cant hear past 20khz: fundamental frequencies still exist in music way beyond 30khz .(they are often called "even order harmonics" that go up to 100khz and beyond) if you don't care about fundamental frequencies or harmonics than you should keep recording at 44.1 but if you do care you should record at higher sample rates. These high frequencies although not audible still resonate and you can still feel and perceive the high frequency content. they also add to the color of the sound.
Agreed, although I'd point out that fundamentals are rarely (if ever) in said range; it's the harmonics you correctly referred to, and odd-order ones too.

This is central to the point I made in a previous post that sum and difference frequencies will be affected too. Some of those harmonics will interact to produce said tones, some of which will be the difference (ie: one freq subtracted from another) between two freqs and others the sum of two or more. Where a subtraction is involved it's easy to see how two higher-than-20k freqs could produce something directly audible.

I also agree with your point that a lot of this stuff is felt, rather than heard. My own theory here is that the brain is allowed to engage in more complex mathematics when these frequencies are allowed through. After all, it's constantly busy adding, subtracting, multiplying and dividing all the frequencies we hear in real time, just for entertainment (to keep itself busy, perhaps). This is why I've also said that I don't see how anyone can perceive sounds as they truly are, 'cause we're constantly adding our own involuntary processing to them.
thashobs wrote:also you cant hear bass below 20 hz but can you feel it?
the answer is yes
so why wouldn't frequencies past 20khz make a difference on the clarity of the HF content
Good point. One doesn't hear nearly as much discussion about this end of the bandwidth chop. I don't know if it's still done (I assume so), but CDs have always been rated as having a 20Hz-20kHz response; the sub 20Hz freqs having been deemed too troublesome to deal with whilst mixing (they obviously can seriously affect energy levels at unexpected points in time as they, by definition, contain more energy). I'd agree with you though that it's only logical to assume that something will be lost in the HPF process.
Last edited by monkey man on Thu Aug 07, 2008 2:17 pm, edited 1 time in total.

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conleycd
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Post by conleycd »

thashobs wrote:analog = infinite sample rate

How do we strive to make digital gear as good as analog? higher sample rates..... new products coming in the next few years include 32-bit 256k sample rates. pro tools as well as all daws will have this.

can you hear a difference between an mp3 at 128k vs. 320k if you answered no than your probably over 30 or are almost deaf.

why do people relate the sample rate as being the frequency response. With all do respect: if you say you cant hear a difference between 192k and 44:1 sample rate your an idiot. First the;192k means that the song is sampled 192 thousand times per second 44.1 is only 44 thousand times per second. If you were to draw an analog waveform it would be perfectly curved. A digital waveform under the microscope looks like jagged stairs. the number of jagged edges depends on the sample rate. the higher the sample rate the smoother the digital representation of the analog waveform. this is why analog sounds so much better. also analogs comparative sample rate of analog gear would be infinite(yes infinity)
the reason for can hear a difference in sample rates is because even though we cant hear past 20khz: fundamental frequencies still exist in music way beyond 30khz .(they are often called "even order harmonics" that go up to 100khz and beyond) if you don't care about fundamental frequencies or harmonics than you should keep recording at 44.1 but if you do care you should record at higher sample rates. These high frequencies although not audible still resonate and you can still feel and perceive the high frequency content. they also add to the color of the sound.

also you cant hear bass below 20 hz but can you feel it?
the answer is yes
so why wouldn't frequencies past 20khz make a difference on the clarity of the HF content
According to this: http://www.lavryengineering.com/documen ... Theory.pdf

Just scroll to the conclusion - you can read the evidence but I doubt you'll be able to interpret it accurately - You don't know what you're talking about.

Apparently anything much higher than 48khz and 96khz at most results in more sampling error, distortion, and overall nastiness as converters round errors in the sampling process.

Even harmonics have nothing to do with an extended range of sampling. It all doesn't matter because your speakers can't reproduce sounds much above the range of hearing. Neither can your ears hear it - that is just a fact.

The Emperor is NOT wearing clothes. Anything you're hearing is worse sound but because of marketing you claim it to be better. We all get suckered into marketing but I think it is funny.

Analog has obvious limitations. Heck most tape decks have about 5% THD - most people don't care and can't hear it so...

We should all probably just focus on making and mixing good music with DP as these arguments are stupid.

CC
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singproinc
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Post by singproinc »

thashobs wrote:can you hear a difference between an mp3 at 128k vs. 320k if you answered no than your probably over 30 or are almost deaf.
Please note that "128k" and "320k" as it relates to mp3's refers to how much data is being transferred in a given slice of time, not the sample rate. Both can be "44.1khz" sample rate; so the difference in those 2 numbers are not sample rates, or even related to sample rates.

It refers to the amount of information that is being transferred in a given period of time. The higher the number, the less the audio content is compressed, and more information must be sent at a higher rate. mp3's throw out audio data ("lossy") to get a lower bit rate or "k" number. You're describing your apples using orange terminology. Very basic stuff, and very important to understand in our business.
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Post by monkey man »

conleycd wrote:Just scroll to the conclusion - you can read the evidence but I doubt you'll be able to interpret it accurately - You don't know what you're talking about.
Nice, and unnecessary, IMHO. Why point someone to literature only to declare that he has no hope of understanding it?
conleycd wrote:Apparently anything much higher than 48khz and 96khz at most results in more sampling error, distortion, and overall nastiness as converters round errors in the sampling process.
Sounds like there's a case for continuing to improve converter technology then, but then any further developments would be hype, right? (See below).
conleycd wrote: Anything you're hearing is worse sound but because of marketing you claim it to be better. We all get suckered into marketing but I think it is funny.
Anything? Yikes.
conleycd wrote:Even harmonics have nothing to do with an extended range of sampling. It all doesn't matter because your speakers can't reproduce sounds much above the range of hearing.
Two words for you: Ribbon tweeters.
conleycd wrote:Analog has obvious limitations. Heck most tape decks have about 5% THD - most people don't care and can't hear it so...
A well-maintained Studer at 30IPS sounds pretty good to me.
conleycd wrote:We should all probably just focus on making and mixing good music with DP as these arguments are stupid.
CC
I hear you and appreciate where you're coming from, but that doesn't mean we should just avoid talking about this or any other technical matters, IMHO.

To my mind the concept is simple: If a mix/performance contains energy content above 20k (even well above), how can its brick-wall-filtered removal be considered progress?

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Post by thashobs »

*****RIDICULOUS POST DELETED BY ADMIN*****
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Post by jamiefennessy »

88.2/96 is quite noticeably better than 44.1....and i would challenge all the naysayers to try this.......... put a steep low pass filter at 18kHZ on a sound source (recorded and mixed and playing back at 96/192)...notice the difference?!? this is exactly what happens when a sound source is reproduced at 44.1 (but not as pronounced) at 44.1, a great big filter is slapped on the signal at 22.05kHz.....still outside the realms of human hearing, but, as any engineer worth their salt will tell you; changing the highs will invariably have an effect on the lows....this is why 96 just sounds better.

Also the idea mentioned somewhere in this thread, that 96 is more "analog" just because of the extra samples per seconds is a fallacy. This notion is a common misconception of sampling theory (as is the notion that analog has, a somehow "infinite" capacity to replicate a sound-source (also mentioned here))
Last edited by jamiefennessy on Fri Aug 08, 2008 6:39 pm, edited 2 times in total.
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monkey man
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Post by monkey man »

Thashobs, it's not too late to tone that post down, you know. It's a great forum, this one, and one you'd surely be better off not being blocked from, eh?

If you don't care, then sorry for the suggestion.
Take care man.

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Post by James Steele »

monkey man wrote:Thashobs, it's not too late to tone that post down...
I appreciate your peacemaking nature Nicky. Unfortunately it was too late for him. I can't believe some people. He's deleted and both IPs he posted from are now on the banned list. Fortunately, he made it an easy decision.

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Post by EMRR »

James, that graphic is blues-approved! :P
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Post by monkey man »

James Steele wrote:
monkey man wrote:Thashobs, it's not too late to tone that post down...
I appreciate your peacemaking nature Nicky. Unfortunately it was too late for him. I can't believe some people. He's deleted and both IPs he posted from are now on the banned list. Fortunately, he made it an easy decision.
Bummer, James. Everything was fine until he suddenly blew a gasket, hence my belief that some fresh cork and glue might do the job.

Disappointing.

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