Bit depth and Sampling rate - the real story.

[Oren]

This is a subject discussed in depth everywhere digital music is made - but I want a definitive thread here at Kara-Moon.
(please only post information you know to be accurate, so we can all use this thread as a reliable resource in our recordings and collaborations )

Marc JX8P and I have discussed collaborating with 24 bit / 48 kilohertz files. Great fidelity with a manageable file size.

Both Audacity and Ardour default to a 32 bit (floating-point) depth and an internal sampling rate of 44.1 kilohertz, but can be set to any standard bit depth and sampling rate up to 24/192.


My questions:

                Would there be any advantage in changing the internal bit depth and sampling rate in Audacity and Ardour to 24/48?

                Are projects destined for CD, MP3, or Ogg Vorbis files with a sampling rate of 44.1 kilohertz best recorded and mixed in my digital audio workstation at 44.1 kilohertz?             

[Moon]

24 bits instead of 16 bit is giving you more headroom to work with, 48khz opposed to 44.1 does not give much extra. Advantage of using 88.2khz (or 96Hz) is less aliasing. Also consider that not all plugins support 88.2 khz or even 48 khz.
Sample rates of 192 kHz only makes sence when recording samples, not realy for making music.

I'm using 24 bit and 44.1 Khz as a standard, 44.1 being the sample rates that complies the CD format (easier for mastering).

Note, this is my humble opinion. Since I miss the added value of working with 48 khz, I've stuck with 44.1khz which is more than enough to record decent music. In the past I did use 96khz, solely for the reason of bringing the latency of my audio card lower. But know with fast cards, cpu's and asio support, this is no longer an issue.

Moon

[Oren]

Moon,
I have been using a 32 bit (floating-point) depth, with the 44.1 kilohertz (Linux default)sample rate, and been very happy with the results. My new computer is fast enough to handle 96 kilohertz processing, so upgrading my audio file quality is now a practical option.

From my research, most experts recommend working at the highest bit-depth and and sampling rate possible to preserve the nuances of the source material, and allow audio processing without losing/corrupting digital information. Apparently there are frequencies humans cannot hear, but can feel, that affect the listening experience. Likewise, audio detail which we may not consciously notice, subtly enhances the sonic landscape. Why not take advantage of the increased processing power a new computer offers to reproduce the musical performance as faithfully as possible?

The other argument is that the intended playback format (CD, Ogg Vorbis, MP3) cannot reproduce the full spectrum of sound resulting from 32/96 audio processing - and many playback devices have severely limited dynamic range and frequency response.
My feeling: Make the best audio possible; then tailor it for each playback situation - big, bold, and beautiful for DVD Audio played through a premium sound system, or compressed and down-converted for lesser formats on low-fidelity systems.

For the next few projects, I'm going to keep the Audacity/Ardour default 32 bit floating-point setting, but increase the sample rate to 96 kilohertz, just to see (hear ?) how the computer performance is affected. Wish me luck...

[Laguna Rising]

I agree with the comments here.
I always work with 24 bit audio for higher resolution (yeah more headroom)

for sample rate it depends on the project. I like to work with 48 khz but if the project has many tracks and many effects my CPU could have problems handling it so if the final result will be CD or MP3 I stay with 44.1 Khz.

Cheers

[tERMoBLUe]

the attention is decisive on integer multipliers  ...cya

<2°TRo²³

[kara]

Right on topic and a good read : http://mixonline.com/recording/mixing/audio_emperors_new_sampling/

k

[Oren]

Good article, Kara!

It is becoming evident that regardless of file size, bit depth, and sample rate,...the actual playback equipment and listening environment are critical to the quality of sound.

Also, the care with which an audio file is prepared will, to a large extent, determine the quality of the listening experience.
A 160 kilobit/second MP3 from RHarv will often sound better than a full 16bit .wav file, just because he knows which frequencies to emphasize, and how far to push the compression to get maximum impact while still preserving dynamics.

[Marc JX8P]

Very true and, even without research, a bit of a common sense issue. There's also, of course, the issue of diminishing returns. There's no doubt that 48 kHz sounds better than 11.025 kHz. But 96 kHz towards 48 kHz will be much more subtle and I'm not even speaking about 192 kHz. Considering bit depth, I think that is more of an issue (when I listen to a DVD movie with music playing at 48 kHz/24 bit there's a significant greater depth to it than similar music on a cd) but ONLY WITH THE RIGHT MUSIC! If the music doesn't have a lot of dynamic range, then you could probably well suffice with 16 bit.

Good article, Kara!

It is becoming evident that regardless of file size, bit depth, and sample rate,...the actual playback equipment and listening environment are critical to the quality of sound.

Also, the care with which an audio file is prepared will, to a large extent, determine the quality of the listening experience.
A 160 kilobit/second MP3 from RHarv will often sound better than a full 16bit .wav file, just because he knows which frequencies to emphasize, and how far to push the compression to get maximum impact while still preserving dynamics.

[Oren]

So, after talking with some very knowledgeable audio enthusiasts and reading as much as possible over the last few years from periodicals and the web, here's how it looks.....

16 bit / 44.1 kilohertz is just fine for preserving audio recordings and exchanging audio files over the web during internet collaborations. The format can be made even more serviceable by compressing the file with MonkeysAudio or FLAC (Free Lossless Audio Codec) for storage or transmission via FTP or e-mail.

Currently, a new audio standard for DVDvideo has been introduced - 24bit / 48kilohertz. For those who want to store digital audio or send audio project files, but at a higher fidelity than the standard WAVE format, 24/48 looks like a very workable choice. Audio file size is kept manageable, dynamic range is significantly enhanced, and those elusive frequencies occurring around the upper limit of human hearing will be more completely preserved.

As for bit depth and sampling rate within your digital audio workstation, the highest values your computer can manage will get you the most accurate processing. Using the Linux workstation, Ardour, in a personal computer with 4 gigabytes of RAM and a dual processor AMD chip clocked at 3 gigahertz, I can comfortably use a 32 bit(floating point) depth, and a sampling rate of 96 kilohertz(96,000 Hz).

More bit depth and higher sampling rates are not absolutely necessary for excellent quality audio, but if you're going for the gusto...
.....that's my story

Comments and criticisms welcome....

[Moon]

The 24 bit / 48khz format can be considered as the standard. I was stull puzzling why most of my gear takes this setting as default. The new standard makes it starting to make sense...

Personally, I don't think that 96khz or 32 floating bit brings additional value, unless you're in the business of sampling.

24 bit / 48khz is giving us enough room to make pro-quality sounding recordings. Why spoiling more cpu anyway ? Is the globe not warm enough ?

Moon

[Oren]

The 24 bit / 48khz format can be considered as the standard. I was still puzzling why most of my gear takes this setting as default. The new standard makes it starting to make sense...
Personally, I don't think that 96khz or 32 floating bit brings additional value, unless you're in the business of sampling.
24 bit / 48khz is giving us enough room to make pro-quality sounding recordings. Why spoiling more cpu anyway ? Is the globe not warm enough ?

Moon,

Agreed; important points....

Personally, I think a 16bit/44.1khz audio file is quite sufficient. Carefully engineered digital audio mastered to this format can sound spectacular.

Most audio processing software designed since Windoze XP  processes audio (internally) at 32bit floating point. It is the default internal bit depth, and seems to work well.
96,000 hertz is, however, more than we need to achieve detailed, spacious sound. My choice would be 44,100Hz. A lot of excellent audio has been processed at 32bit(floating point) / 44,100Hz.

(however, since I handle other people's audio mixing and mastering, and that can involve a lot of intensive digital processing, the higher numbers discussed in the last post assure that they are getting the most comprehensive audio performance available)

[Wyatt]

Personally, I think a 16bit/44.1khz audio file is quite sufficient.

Excellent point..

Carefully engineered digital audio mastered to this format can sound spectacular.

..and you have certainly demonstrated that.

Wyatt

[Oren]

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[Laguna Rising]

Carefully engineered digital audio mastered to this format can sound spectacular.

..and you have certainly demonstrated that.

Wyatt

+1   

[Oren]

Thanks, L.R.

It was the quality of audio production on the forum posts that attracted me to this site. A lot of our members have advanced production skills and refined musical abilities (look in the mirror, fella ). Perhaps more so than anywhere else on the web....