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levelbest
08-25-2004, 06:22 AM
Can anyone tell me why I might want to record in 24 bit over 16 bit? I don't really know what bits they are referring too? This is in reference to a decision to choose a audio input recorder in OS X. I have been demoing Sound Studio, which can record at 24 bit rate. And I like it, but it is fairly pricey, well pricey compared to freeware but not so compared to really high end apps, about $60 if I remember correctly.

I am also downloading Final Vinyl, Audacity, and AudiocorderosX. I Have not looked at each one yet but some are only 16 bit, bit 24 like Sound Studio. What sort of a difference will this make in my recordings?

I just scored an old Nakamichi BX-150 at a yard sale last weekend and I am enjoying putting my old cassette tapes into my mac (while I am working on the video project, mentioned in another thread). I love the sound it gives the old cassettes and I want to get every nuance out of the old tapes. If 24 bit gives better tonality or some such then I will just pay for Sound Studio.

Any thoughts on this?

Thanks

lb

levelbest
08-25-2004, 08:14 AM
Oh, H-E L P !!
This sort of relates to the same thread so I am posting it here. After trying Audacity, something changed, and I can't find how to correct it. Now the sound input from my iMic seems well, hosed. IT is highly muted and it sounds like it is under water. Sounds to my ear like something is blown, or is highly over-modulated now.

Testing:
1) I ran the deck through the receiver and it is still coming out clean.
2) I look at the VUE lights in Final Vinyl and in Sound Studio and they don't seem to be peaking at all. They look like they are getting the normal signal from the input.
3) I looked in the sound preferences and made sure it was set to the correct input, etc.
4) I booted from and ran Disk warrior
5) Using OnyX I trashed the system and user cache files
6) I ran the chron scripts
7) I rebuilt permissions.

I will run PCC and do tha prebinding thing and any other thing PACC does that OnyX does not do. BUt mostly, that is all I know to do.

I can't imagine that I could have changed anything that did such damage to the sound. iMic input is completely unusable right now. I have not tested this through the Turntable but since the cassette is otherwise outputting correctly I can't see how it would change anything.

I have one other USB port on this G4 which I can try, assuming the USB inputs are different circuits. IF anyone has any brilliant, or even simple, solutions, oh please, lay them on me.

lb

Macaholic
08-25-2004, 09:34 AM
I Don't know if this helps...
From Audacity:
"Griffin iMic problem

There is a bug when using Audacity with the Griffin iMic, or with H&K soundsticks, which re-sets recording to mono 8bit only. The work around is to re-set the OS X audio parameters after starting audacity:

FYI, this bug has been found; the fix will appear in Audacity 1.2.2, whenever it is released. -Dominic Mazzoni

First, open the "Audio MIDI Setup" program in the "Utilities" folder, under Applications.

1. Start Audacity 1.2. When its window opens, note that the FORMAT SETTINGS FOR iMIC HAVE CHANGED IN "AUDIO MIDI SETUP" FROM "2ch-16bit" TO "1ch-8bit". This happens independently of whether I have last used Audacity with a recording setting of "1 (Mono)" or "2 (Stereo)".

2. With the iMic settings now incorrect, I can only get single channel input in Audacity with either "1 (Mono)" or "2 (Stereo)" selected in its preferences.

3. If I manually restore the correct iMic format settings (i.e., "2ch-16bit") in Audio MIDI Setup WITHOUT QUITTING Audacity, I can then record stereo input in Audacity.

[A second user notes he has the same problem, which the above workaround/explanation helped him figure out. It is very annoying. It does appear to be some kind of a bug in Audacity. Note that after Audacity launches and somehow mis-sets the parameters for the iMic as a port, even other OSX recording software will refuse to recognize that the iMic is stereo. I would be so very happy if it were fixed. ]

Audio Midi Setup can be found under /applications/utilities


under which versions of OS X? Will this fix work on 10.1, say?


It worked for me under 10.3.4. God, I was going nuts until I found these notes; the effect of the settings change for me was horribly noisy and distorted recordings across the board, all applications, rendering my system unuseable for audio recording! -- Mark




* This is not necessarily a bug in Audacity -- it affects numerous audio softwares (virtually any soft synth) running on OSX (Jaguar or Panther) with the Griffin iMic. Griffin technical staff point the finger at Apple, stating that it's a bug in OSX.

levelbest
08-25-2004, 09:53 AM
Thanks. I will digest your post and see what happens. I switched the USB port on my G4 and it is working again. Maybe under 10.3.5 each USB port has it's own settings and the bug only clonked one of em? It will be good to know I didn't fry anything.

On a completely off topic note, I have my 16 year old nephew staying with me. I gave over my old 7300 thinking it was pretty bullet proof and, he has it so it will not boot up. IT chimes but no video. I reset the cuda, swapped memory, processor, video... I better stop here or I will owe a new thread.

Suffice it to say with the audio acting like an overblown circuit, it will be very good to find that it was a stupid port setting and nothing really serious.

lb

--> Updated Edit:

IT worked out just as you said. Thanks. I have both USB ports back now. I didn't even realize that there were additional sound settings under X than the sound prefs pane. I learned a good lesson today. I put the Midi and the sound prefs pane with my other sound project stuff on my Butler menu (Butler rocks).

BTW, if this machine is 16 bit, as referenced in the midi sound application, does this answer the question I began this thread with? Does 24 bit in Sound Studio really not make any difference for my purposes. cutting records and old cassette tapes into AIFF files (later MP3 files)?

rwm
08-25-2004, 10:13 AM
lb

There are differences in the USB ports (keyboard vs back of puter) and devices you plug into them but thats about all I can tell you. :(

This was posted when I was trouble shooting a bad mouse or was it because I am still using it. :D

Randy,

One more thing (buzzer shot) in case your haven't tried -- you indicate possible visible damage.

Optical mice are actually present quite a load on the USB bus to supply the power. In such cases you don't want to plug the device into bus-powered hubs, and the hub in your keyboard is bus-powered not self-powered.

So plug the mouse directly into the computer or into a powered hub and see if its any better. There used to be and may still be an Apple kbase article on this when using an optical mouse -- in fact impetus was the original Apple optical mouse.

levelbest
08-25-2004, 10:29 AM
Optical mice are actually present quite a load on the USB bus to supply the power. In such cases you don't want to plug the device into bus-powered hubs, and the hub in your keyboard is bus-powered not self-powered.

So plug the mouse directly into the computer or into a powered hub and see if its any better. There used to be and may still be an Apple kbase article on this when using an optical mouse -- in fact impetus was the original Apple optical mouse.I did not know this. My Mouse (MS Explorer trackball) does have a really long cord so this is easily done. I think it was beyond stupid of Apple to sell the G4 that is obviously going to be sitting on the floor, combined with a keyboard that has a USB cord that can't reach off the desktop. I have a USB hub like anyone has to have with a new Mac (Stupid fruit). Not that it doesn't come in really handy with my camera downloading or my scanner, etc.

BTW, it was probably a dumb idea of mine to add to my earlier post with an edit but please note my earlier reply was revised a bit.

Still wondering about the 16 or 24 bit with Sound Studio or Final Vinyl.

Thanks all. - lb

Macaholic
08-25-2004, 11:16 AM
Cool LB, Glad it worked!
16 vs 24 bit huh?
1st,CDs are 16 bit. So if your audio needs are for Mp3s, AIFFs and not intense
audio recording and mixdown you will be fine with 16 bit.

For Pro Audio, 24 bit recording offers more dynamic range,captures more nuances of an instrument prior to mixdown.Similar to a Graphics Pro desiring a
High Resolution image to manipulate prior to printing.

Here are a couple of links that go into more detail
http://homerecording.com/digital_primer.html
http://www.24bitfaq.org/#Q0_1_1

Hope this helps.
Dave

levelbest
08-25-2004, 11:55 AM
But we can surely say that the edge 24-bit recording has over their 16-bit counterparts puts a big smile on the audiophiles face. Why? What’s missing on my 16-recording?

Simply, the answer is detail. The PCM format provides its optimal resolution when signal levels are at their very highest. As signal levels decrease to lower levels, resolution deteriorates, leaving quiet cymbals and string instruments sounding typically sterile, dry, harsh, and lifeless. The more bits you have available to you in the process of quantizing the amplitude of a wave form at any given sampling, the more accurately a lower level signal can be represented. If an instrument is very loud while standing next to it, but is recorded at a low level, there are less numbers that can be used to represent just exactly how loud it is at any given moment. We know that a wave modulates between silence and its maximum amplitude or volume, while the number of times per second this modulation occurs gives us the pitch of the wave.Thanks, it helps a lot. I just finished recording a side of a cassette with Final Vinyl. It decided to quit after I tried opening the editor. That makes 3 complete sudden quits in Final Vinyl in an hours testing. Hmmmm...

I do like Sound Studio. I am glad to know that the 24 bit recording choice sounding better wasn't just my imagination. I suppose, barring another possibility being out there that no one has mentioned, I will get Sound Studio. It's still a little pricey when there are so many freeware and lower cost shareware products out there. But it's 24 bit, doesn't crash at all, and it's pretty darned intuitive to work with. I lucked into this old Nak deck for $15 and it is much nicer sounding than these old cassettes sounded previously, so I can always rationalize the money that I didn't spend on the Nak, going toward Sound Studio.

lb

"Rationalizations are more important than sex. If you don't believe me, when was the last time you went a whole day without a rationalization?" - Woody Allen

rwm
08-25-2004, 11:55 AM
LB

Here is that entire thread http://www.macgurus.com/forums/showthread.php?t=13878

eric's post number 10 references things a little better.

Sorry I can't heklp with the 16 vs 24 bit issue.

Your working on a project that I was going to do last winter ... maybe this winter.

Good luck
Randy

rwm
08-25-2004, 11:58 AM
Which computer are you using?

levelbest
08-25-2004, 12:14 PM
G4 1 Ghz MDD
1.25 Ram
Stock machine

- lb

Tim Casey
12-15-2004, 12:36 PM
Record in 24 bit if you're doing multitracking (a bunch of individual instruments). It really does make an audible difference in the end - you'll notice more detail and less "grit". The combined noise floor of, say, 12 tracks of 24-bit audio files is still lower than the noise floor of a stereo 16-bit master, whereas 12 tracks of 16-bit audio files have a combined noise floor above that of a 16-bit master.

When I first started doing computer audio recordings exclusively, my first project sounded kinda gritty (it fit the music on that project well, though). When I switched to 24-bit, the final masters sounded a lot clearer.

It puts more strain on the CPU and takes 50% more space on your hard drive, but it really does make a difference on your final 16-bit master.

(I also should mention that most of my friends can't hear the difference, but I can. I'm not an audiophile freak, just someone who's got pretty good ears.)

rwm
12-15-2004, 01:03 PM
Tim

WHAT was that... again :D Just kidding.

My ears were good once before they were introduced to many hard drives and fans with various spinning noises and pitches.

Thanks for the first hand input - we appreciate it.

Randy

revi
12-15-2004, 06:18 PM
Greetings,

16 and 24 bit refer to the bit-depth of the recording dynamics.

Specifically, when recording 16-bit depth, 16 bits are used to measure the dynamics (i.e., amplitude, loudness/softness, etc.) of the signal. Thus the hardware/software are differentiating between 2^16 (2 to the 16th power = 65,536) levels of loudness...that signals will be assigned a "loudness" on a scale of 0 to 65,535.

24-bit thusly involves 2^24 (2 to the 24th power = 16,777,216) levels of loudness.

Now this doesn't mean that your music is 2^8 = 256 times as loud, but that there are 256 times as many values...hence the previously mentioned reduction in "graininess" or "grit": you are making much finer measurements of dynamics so you can, for instance, tell subtle differences in loudness in quiet passages (e.g., acoustic music or a vocalist who's signing in a subdued fashion).

24 bit is the way to go. Ideally, record at 24-bit 48kHz and dither down to 16-bit 44.1 kHz at the end for mastering/burning CDs. At least if your recording music. Spoken word may work just fine at 16/44.1.

HTH

iver

P.S.

Here's a _dynamite_ book on mastering audio:

http://www.amazon.com/exec/obidos/tg/detail/-/0240805453/qid=1103162981/

When you understand it, please contact me and explain it to me. ;-)

Bob Katz is a famous person in these things.

BTW, all this is analogous to graphics where an image can use 2 = 1-bit, 4 = 2-bit, 8 = 3-bit, 16 = 4-bit and however many colors. RGB color is 24-bit: 8 bits each for Red, Green and Blue. The higher the bit-depth, the more colors, the more one can capture "photo-realistic" variations.

You can see this in HTML colors where 2 hex characters are used for each color value: hex values go from 0 to 15: 0,1,2,3,4,5,6,7,8,9A,B,C,D,E,F where A through F are used for the values 10 through 15. Thus FF = 15*16 + 15 = 255

white = FFFFFF = FF (Red) + FF (Green) + FF (Blue) = 255 255 255
red = FFFFFF = FF (Red) + 00 (Green) + 00 (Blue) = 255 0 0
blue = FFFFFF = 00 (Red) + FF (Green) + 00 (Blue) = 0 255 0
green = FFFFFF = 00 (Red) + 00 (Green) + FF (Blue) = 0 0 255
black = FFFFFF = 00 (Red) + 00 (Green) + 00 (Blue) = 0 0 0

24 bit color is 16,777,216 colors (also btw, 32-bit color isn't more colors, it's just apparently easier for the graphics card to process the colors as 4 byte chunks than 3 byte chunks).

Also note that in graphics as well, that excessive bit-depth will just eat up space and make bigger files. If you've got line art (e.g., a logo), you likely don't need 24-bit color...in fact, you might make the logo "muddy" if you use too many colors. In audio, the temptation is to go high bit depth, high sample rate...but there are points of diminishing returns. 24-bit, 48kHz appears to be a real good place for making recordings to be realized as CDs. Some machines like ProTools HD, Apogee stuff or MotU HD192 will do 24-bit _192_kHz recordings! You're _really_ eating up diskspace at that point.

Here's one more note: sample rate (e.g., 48kHz) is dividing up time into slices whereas bit-depth (e.g., 24-bit) is dividing dynamics into slices. The more slices, just like more colors, the more gradation you can capture.

M.Brane
12-15-2004, 06:54 PM
Bottom line is if you're working with music that has a lot of dynamic range more bits is better. If you're working on loud rock/pop/rap stuff 16 bits is just fine.

I'm a hard rock guy myself, but also dig jazz, and classical. ;)

The only advantage to more bits is more dynamic range. Or if you record hot a lower noise floor. Naturally this is of dubious value if your material only has a 6db peak-to-peak ratio.

The only advantage to higher sample rates is an extended high frequency response. It is debatable wether this makes a huge difference in sound quality or not after the material is downsampled. I like analog tape, and vinyl BTW.

Timing of the samples is another matter entirely. Accurate clocking is essential for proper sampling, and reconstruction of the waveforms by the converters. You can spend well over $1k for a good clock alone.

Finally the analog low-pass filtering components in the converters are key to getting good samples with a minimum of artifacts. Ironic eh?

I'll take a high-quality 16bit converter over a cheap 24bit any day. :p

revi
12-15-2004, 07:22 PM
What the heck, let's keep this thread going...

I'd been recording primarily rap/r-n-b over the last 15 years; originally on tape (though I couldn't afford 2") and then standalone DAWs (E-Mu DARWIN) and now computer (Digital Performer and ProTools [_just_ getting into PT]).

I have to say that I'm a convert to 24-bit, even on the rock/rap side of things...though it depends on what _kind_ of rock/rap you're going for. If I had the opportunity to record the Ramones or Sex Pistols or early Black Flag, I could easily see going 2" tape just for the natural tape compression...the music was raw and _live_, didn't have much frequency variation/range and was _loud_. On the other hand, if I were going for a new release by Yes or Pink Floyd (ok, let's pretend it's the early 70's but we've got today's gear)....man, I'd likely go full-bore ProTools|HD and 24-bit all-out just for the uber-massive track count with zip noise aspect. It does matter what you're recording.

However, and I admit I'm likely showing the zeal of a convert, the argument for going 24-bit 48kHz and dithering down is pretty compelling. There's a lot of good, reasonably priced, 24-bit gear out there nowadays: both MotU and Digi have got some compelling offerings. The selection is, like all things computer/digital, much greater than even a few years ago.

But, yes, there are issues of good clocks and A/D converters (indeed the low pass stuff is to avoid the Nyquist frequencies).

I did a rap project a bit ago at 16-bit and kinda wish I could do it again (well, also to correct my mistakes) at 24-bit. Still would keep it raw...and indeed, MBrane, the noise floor aspect is another very compelling reason...but would like that additional fineness.

So, I'm not compulsive (heh), but for those not familiar with the arithmetic involved:

"Red Book" audio is 16-bit, 44.1kHz. "Red Book" is the specification for CDs.

16 bits = 2 bytes

So, at 44,100 samples a second (this is one channel, mono):

(16 bits/sample)*(2 bytes/16 bits)*(44,100 samples/sec)*(60 sec/minute) = 5,292,000 bytes/minute

and thus 10,584,000 bytes/minute stereo.

So, if you're doing 24-bit 48kHz recording:

(24 bits/sample)*(3 bytes/24 bits)*(48000 samples/sec)*(60 sec/minute) = 8,640,000 bytes/minute mono

17,280,000 minute/stereo

So, one needs to plan ahead if multi-tracking stereo stuff is desired.

Also, finally, at a naive level, think of two axes:

y-axis = vertical axis = signal strength = dynamics = volume
x-axis = horizontal axis = time = "wavelength" ~ Constant/frequency

So bit depth is chopping up the y-axis and sample speed is chopping up the x-axis. Needless to say, this is _very_ sketchy and it doesn't take too long to go wading into coding/information theory and also good ol', gorgeous Fourier analysis.

This is fun stuff.

Macaholic
12-15-2004, 07:52 PM
Wow an old thread!
Keywords, Digital, Amplitude, Trunicate, Dynamics.
And remember Cd's are 16 bit.
Oops almost forgot another keyword, Normalized, or the highest digital signal prior to distortion,
Can you say MP3,
Wow, 2" tape? I LOVE it!
Dave

Tim Casey
12-16-2004, 02:50 AM
Even if you're recording the loudest heavy metal band in the world, do it in 24 bits. The summation of a bunch of 16-bit tracks into a two-track (or 5.1 track if you're adventurous like me) master is what sounds crappy to my ears. It'd change the sound of the heavy metal band if it were all done in 16 bits.

Of course, that may not be a bad thing, depending on the band... ;)

M.Brane
12-16-2004, 11:01 PM
Well since all sound is analog it doesn't really matter how you slice it, and reconstruct it as long is it is done as accurately as possible.

I contend that timing, and filtering issues are of greater importance than dynamic range, and frequency response.

It is a known fact that our ears are relatively insensitive to the amounts of harmonic distortion in most modern audio gear of good quality.

Have you looked at the headroom, and frequency response specs of your average boutique mic pres/ vintage Neve/MCI console, or 2" machine lately? :D

What really kills me is people who spend so much money to do HD audio in tracking/mixing, and then have their stuff mastered so hot the meters never drop below -6db during any song. What a waste.

Tim Casey
12-17-2004, 02:45 AM
I'm just starting to hear the differences between a stereo SACD and a stereo CD, so I agree that it's not all that supercritical when listening to a master. But I can really hear the difference on my multitracks between 16 and 24 bit, especially as the track count gets highger.

I've also NEVER been able to hear the difference between 48 and 44.1 kHz sampling rates, so I have no idea why anyone would record all their multitracks at 48 and then convert the master to 44.1. I would imagine that that would cause more sonic problems than it would solve.