sample rates issue

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chees-its

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hi i'm wondering im using logic pro and i want the best possible quality audio for my guitar recordings ... the problems i'm having are alot of cpu overload as well as when i bounce my songs which are in 24 bit /96khz into mp3 i always get the message that the destination does not accept any sample rates above 48 khz ? should i just record at 48 khz then ? it seems silly to have a interface capable of 96 khz but not to be able to record at those rates
 
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hi i'm wondering im using logic pro and i want the best possible quality audio for my guitar recordings ... the problems i'm having are alot of cpu overload as well as when i bounce my songs which are in 24 bit /96khz into mp3 i always get the message that the destination does not accept any sample rates above 48 khz ? should i just record at 48 khz then ? it seems silly to have a interface capable of 96 khz but not to be able to record at those rates
Oh, chees-its, you have no idea what a contentious topic this can sometimes be. You might want to put your helmet on, grab a huge bowl of popcorn, and sit back and watch the fireworks ensue ;).

The best answer (though not the only one) is that any currently-available sample rate for audio only that rises above 44.1kHz is little more than a waste of time; with two caveats:

First, if you're doing audio-for-video, then you might want to work at 48kHz. Otherwise, don't worry about it.

Second, if you have converters whose *circuit design* (note the difference between "circuit design" and "sample rate") just so happens to sound significantly better when operating at a higher sample rate, enough to make it worth the extra cost in sample rate conversions and CPU and storage use later on. In other words, if it really does sound better (honestly) after your project is done and all the dust is settled to use a different sample rate setting, then by all means, knock yourself out. But this is not always going to be the case with all converters.

Those caveats aside, the best general consensus from most folks who've been around the block more than a couple of times is that it's best to just work at 44.1k, 24-bit and move on from there to the real problames with the recording. Sample rate is such a *minor* issue compared to the real issues such as acoustics, technique, signal chain, etc., that by the time you get far enough down the list to have to really worry about sample rate, you've already solved so many other major problems that you'll have a recording that'll be of superior quality at any sample rate anyway.

And now, here will come those who will vehemently disagree...

G.
 
This is a quandary we all face.

I now record at 24 bit 96 Khz since I started using a new recording program called Record made by Propellerhead.

This is a step up from the 24 bit 44.1 Khz I was using with my stand alone Tascam 2488.

Some say they can’t tell the difference between 44.1 and 96 Khz, I don’t know about that but at some point if we want to share the music we have to convert to mp3.

I don’t understand why your destination does not accept any sample rates above 48 khz but that’s beside the point. If you’re set on that destination then you have to give it what it wants.

At home I revel in all my 24 bit 96 Khz glory and my mp3 translate pretty well. If you’re hearing drastic differences you may have other problems.

It’s not silly to have an interface capable of 96 khz but not to be able to record at those rates, think of all the analog guys – they must really go wild when they have to convert to digital.
 
well i believe by destination it just means the bounce into mp3 format from logic...does this sound correct ?
 
Are you trying to record as MP3 files at 24/96...???...or trying to covert to MP3 from 24/96 WAV files?

I track at 24/88.2 ('cuz I like the math :) ) as WAV files, and then convert my final CD WAV files to 16/44.1...but for MP3 files, it's a much lower quality than that.

To go to MP3 you have to "knock" 'em down....
 
i'm trying to bounce my songs directly from logic to an mp3 on my desktop and it say the destination does not accept above 48khz ... so now i'm thinking of just recording them at 48 and forget about 96 for now
 
Why record at 48kHz (unless your target is video)?

Resampling from 48kHz is 44.1kHz is a freakishly messy calculation, and so few resamplers are up to the task - You can potentially cause far more damage than simply recording at the target rate (which you'll find is what 70-80% of full-time industry professionals do regularly).
 
You can do that...48kHz is not going to sound bad, but some people prefer recording at the higher rates and then converting down to the desired final format. You get a little better audio quality doing that over the lower rates...but it's nothing dramatic.

But here as a question...why don't you just create an MP3 file within logic to your desired playback bit rate (160, 256, or 320...the more common ones for "decent" music playback).

What do you mean "bounce to desktop"...?...why do you need to do that?
I use Samplitude, and from my original 24/88.2 file...I can Export directly to an MP3 file, there's no need to “resample” as an MP3 at 48kHz...before compressing to your final playback rate.

Just not sure what steps you are doing...????
 
You get a little better audio quality doing that over the lower rates...but it's nothing dramatic.
This is entirely dependent upon the converter. Some converters sound better at 44.1 than at 88.2, some vice versa, and some no different at all at either rate. And it has *nothing* to do with the sample rate itself, but rather with the design of the converter.

Chees-its, it's not silly to have 96k and not use it, it's silly for that 96k to even be on that machine in the first place. The only reasons it's there is because of the large number of EEs out there that don't truly understand digital information theory, and the even larger number of sales and marketing people who don't care; they just see "more is better" as an obvious "marketing truth" and a super-easy sell.

G.
 
Like I said...it's nothing dramatic. :)
And I agree it's a convert-to-converter thing...though the underlying theory (for whatever it's worth) implies that more samples per second = much finer "slices" of the audio you are sampling…
...and heck, we all know that hard salami tastes MUCH better when it's sliced very thin. ;)

I like mine sliced at 88.2 :D

I guess the more important point he should be aware of is the bit-depth….


But his issue/concern isn't so much about what rate is best, anyway (from what I'm reading)...it's more to do with him trying to sample MP3's at above-48kHz rates and wondering why it won't work.
 
And I agree it's a convert-to-converter thing...though the underlying theory (for whatever it's worth) implies that more samples per second = much finer "slices" of the audio you are sampling…
Actually what the underlying theory - specifically, the Nyquist theorum - states is that in order to losslessly reproduce an analog frequency, one needs to double the frequency for the sampling rate.

For real-world reasons such as aliasing and physical low-pass filter characteristics, real world sampling rates are slightly higher than the theory stipulates; this is why we sample at 44.1k instead of an even 40k in order to cover the audible audio spectrum.

But the "more slices" interpretation is anything from a bit misleading to downright incorrect the way it's represented in many textbooks. A 44.1k sample wont reproduce a (for example) 10k signal any better than a 25k sample rate will. Assuming all other physical design characteristics of the circuit being equal, the difference in sample rate will have zero effect at that frequency. Any increase in "resolution" translates into an increase in frequency response, not in accuracy at that frequency.

The same holds true for 44.1 vs 88.2 or 96. Assuming you have a 44.1k D/A that is designed well enough not to add any artifacting at 20k because it's filters and such are designed well enough, an equally-designed 88.2 D/A won't do any better of a job with 20k than the 44.1 will. It will simply increase the frequency response to 40k.

Then when you figure in that, unless you are recording a clean synth with HF information direct, your recording signal chain *before* the converter probably won't take you to 20k anyway, the extra sample rate is superfluous.
...and heck, we all know that hard salami tastes MUCH better when it's sliced very thin. ;)
That, OTOH, is very true! :D

It's just not an accurate analogy for digital theory. I'm not knocking you for selecting 88.2; go ahead and use whatever sounds best and works best for you. I'm just relating that if 88.2 sounds better for you, it's probably because of a poor design at 44.1, not because of the actual sample rate itself, that's all.
I guess the more important point he should be aware of is the bit-depth
Also agreed. And I think there's a pretty good consensus that 24bit is the way to go there, with the option of using plugs that can go to 32bit floating point of you want.
But his issue/concern isn't so much about what rate is best, anyway (from what I'm reading)...it's more to do with him trying to sample MP3's at above-48kHz rates and wondering why it won't work.
True, but he did raise the question/point of he thought it was silly not to use 96k as long as it was there. I (and others here) we're just pointing out that it's not really necessarily as silly as it might seem at first blush, and that it can in just as many cases be silly to automatically use it by assuming it is automatically better.

As far as the converting to MP3 thing, I'd recommend saving a target file as WAV first, and make that your master copy. Then if you want to step down to MP3s for distribution, do it from there.

I'm not intimately familiar with Sonar, but I wouldn't be completely surprised if it's MP3 encoder simply isn't designed to work at bitmapped rates of higher than 48k. It probably would not be the first nor the last encoder out there to have that kind of limitation. This should be documented in the apps online help, I would think.

If that's the case, what I would recommend, if he decides to stay at 96k/24-bit for his work, is to save his masters as 96k/24-bit WAV, just so he has a clean, unadulterated copy of his final work. Then for duplication purposes, make a duplication master WAV at 48k or 44.1k and 24-bit, and use that to make his MP3 encodings.

G.
 
OK, the steps im doing are minimal... im on a mac and im simply bouncing my logic pro project to an mp3 ... using whatever converter is in logic i guess... on my desktop, simply cause it's handy, so i can upload the mp3 to my website
 
Agree with the pro guys above. Reason?

Commercial/industrial film engineers like the industry standard of 24/48. They sneer at foolishness beyond that. [from a pro recordist friend who does projects with Disney guys in NY]

If you want the best product you can make, available for any medium....and you never know where your music is going to go....record everything at 24/48, store it, and let the pro engineers, who work for the people who will license your music, convert it down to the application's requirement. They have better ears and conversion routines. [That's from a film/radio, tv music publisher and film maker....who strongly suggested I do the same to make my work the most technically/market desireable it can be.]

2c
 
OK, the steps im doing are minimal... im on a mac and im simply bouncing my logic pro project to an mp3 ... using whatever converter is in logic i guess... on my desktop, simply cause it's handy, so i can upload the mp3 to my website

chees-its--
I'd post this in the Logic forum.
Maybe someone who knows the ins and out of that specific program can help you.
 
But the "more slices" interpretation is anything from a bit misleading to downright incorrect the way it's represented in many textbooks. A 44.1k sample wont reproduce a (for example) 10k signal any better than a 25k sample rate will. Assuming all other physical design characteristics of the circuit being equal, the difference in sample rate will have zero effect at that frequency. Any increase in "resolution" translates into an increase in frequency response, not in accuracy at that frequency.

Yeah the "more slices" analogy has been used so many times...I think it’s hard to get away from it mostly because people can visual it.

AFA the argument about 96k not being any "better" than 44.1...etc...there's been all kinds of endless debates on that, and of course, the fact the ALL converter manufacturers include multiple rates on their boxes only further clouds the issue.
I remembers a rather looooooooong forum debate that went on for hundreds of pages back in 2002/2003 with George Massenburg on another forum...and at the end of the debate, I don't think anyone proved anything even though the "math" seemed to be indisputable.

Of all the pros out there who have the high-end $$$ converters with multiple rates...how many use the lowest rates instead of the highest? :)
If the math proves it....there are an awful lot of pros who still ignore it.
Maybe it's just some form of mental assurance to go for the higher rates...I dunno?

In my case, I figure if the PC can handle it and I have enough storage space...why not? :D

It’s sorta like the speed limit…
If we can only go 55/65 legally…why do they still make cars that can do 120 mph???? ;)
 
Yeah the "more slices" analogy has been used so many times...I think it’s hard to get away from it mostly because people can visual it.
The easiest way to combat that is fight pictures with pictures.

Everyone agrees that the theorem says that the sample rate needs to be twice the frequency,minimum. So what you do is draw a sine wave. then draw two samples taken from a random starting location anywhere along that sine wave. Now erase the sine wave and show them just the two samples and ask them to create for certain the correct sine wave from just those two samples. They can't. In fact, double the sample rate to 88.2 and draw four samples on a 20kHz wave, and repeat the process, and ask the user to draw for certain the correct sine wave. They still can't. No one can. Because that's not how the theorem ultimately works. The "stairstep/slice" diagram may be a simple way to look at it, but it leads to all sorts of wrong conclusions.

Forum arguments are useless because 99% of those making arguments ignore three points: they have no idea how it actually works, they ignore the other variables (such as converter design) that can be affecting what they're hearing, and, I have NEVER, ever seen a truly scientific, double-blind-with-control test done or cited in any of these or forums that result in any actual data worth putting any weight on.

Like I say, if your converter sounds better at 88.2, *and sounds better enough to more than cover the damage done during sample rate conversion down to the master or target sample rate*, than knock yourself out. But when it comes time to change your converter due to breakdown or upgrade, the same night not hold true.

But no matter how you slice the issue (pun intended :D), it definitely not worth your average home recorder even worrying about. When you can't even play your instrument, and then record that instrument with a $100 microphone placed squarely on an amp dustcap in a room with all the acoustics of a porta potty, record it through a $30 preamp and $30 converter, mix it through crap speakers, and then smash it flat as a penny on a railroad track in mastering, what sample rate they do all that at ain't gonna make one single bit of difference ;) :D.
It’s sorta like the speed limit…
If we can only go 55/65 legally…why do they still make cars that can do 120 mph???? ;)
Because it sells cars.

G.
 
If we can only go 55/65 legally…why do they still make cars that can do 120 mph???? ;)
So that a lunatic like me, can take a calculated risk, go to an out-of-sight curvy road and pretend to be Michael Schumacher :D

Plus, most of the cars sold in the US aren't made for the US market only, and in Germany for example there are no speed limits (well, that's changing, but let's not dice that one) on the autobahn.

As for higher sample-rates. Unless you have a converter with rock-solid clocks, it's actually going to cause issues with stereo image and cause fussyness due to added jitter, etc. So you end up burning more fuel... uhhh.. use more HD space, and then go to jail for likely bad audio quality. :p
 
I always wonder about industry pros...the ones with the golden ears...making claims about greater clarity and depth when they switch their expensive converter from 48 to 96 to 192.

I mean....sure there's the math, but what are these guys really hearing?
If they use the same converter and just flip their sample rates...what else is different?

And I don't ask that question to initiate a deep debate about sampling rates...but I'm just pointing out why so many people who are not golden ear pros end up considering that notion that more=better.
They are being TOLD it does...by people they respect/admire/believe...etc,.

I've not done any double-blind studies with my own gear...but way back, I happened on the 88.2 frequency partly because the sampling rate debate was raging, and I figured I would just hedge my bets and go for the "medium" higher rate of 88.2 since my PC & drives could handle it...
...plus I liked the fact that it was a clean reduction to 44.1...
...and I've just never bothered to reinvestigate or experiment with anything else.

It sounds good...I'm not going to fix it. ;)

But maybe when I finish my album project in the next few weeks...since I'm going to be swapping out my DAW PC for a touch more kick after that, as I would like to try some ITB/plugin mixing just for the ha-has, just in case I get tired of doing things OTB… ;)
…...I might also do some testing with a couple of sample rates and see if I can tell which one sounds better with my rig.

Oh...and that's partly the other reason I get away with 88.2...I don't mix ITB...so my PC doesn't even blink with the higher rates and bigger files. I'm sure that going ITB it would change the load...but then, that's one reaon I'm going to switch out my DAW PC to a bit mor epower....to head that problem off.
 
Sooo....quantization error.....


Well, someone had to say it.

Cheers!
 
I would just hedge my bets and go for the "medium" higher rate of 88.2 since my PC & drives could handle it...
...plus I liked the fact that it was a clean reduction to 44.1...
Actually that's another misconception that because 44.1 is exactly half of 88.2, the math is simple and it just consists of dividing the number of samples by 2. For proper sample rate reduction, there is still quite a bit of tricky math and averaging going on.

I can honestly say I cannot hear a difference between the various sample rates (exception being 32k) when flipping through them on my Aardvark Pro Q10. But then again, it's a mid-range interface, and my room acoustics leave much to be desired.
 
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