Final Mix - mix the VST or WAV files

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ChrissMusic

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Hello, I often have different questions regarding mixing and mastering and I found this forum that might be useful.

I have written a song which consists in guitar, bass, drums, percussion and a small violin. The guitar is real, but the other instruments are VST. My question is: should I export my vst instruments to Wav before the final mix, or let them VST as they are?

Thank you
 
You should always bounce your audio to a wav file at the highest bit depth and sample rate possible for mixing. This way you know exactly what type of file you are using to mix with. VST's sometimes mix 16bit with 24bit files and they may have some artifacts. Most audio plug-ins are designed to work with wave files and can give you better control over compression and EQ. Reverb sounds better when you add it to an audio file as well. Depending on the DAW that your using, you may have some really cool tools at your disposal that can not be added to an instrument track. Last but not least, VST's take up too much CPU. Using .Wav files to mix with will save you some CPU and allow you to add more plug-ins and AUX tracks for Sub mixs and effects channels. Now of course just as most things, everyone has a way of doing it. You could mix with the VST's, I personally don't think that you would get the best sound possible. Also you wouldn't send a mixing engineer a bunch of VST's to mix, because he or she may not have those. You Should always mix with high resolution .Wav Files.
 
Thank you for answering so fast. First of all, I'm using Cubase. I'm not planning to send my tracks to another mixing engineer, just looking forward to improve my abilities and reach the best quality I could get. CPU isn't a problem, I'm running an Intel i5, although I often have Asio overload problems. Could you give me some advice on which type of WAV should I use for the VST tracks, or it's not standard? Should I use maximum bit depth for best quality?

I also use different FX channels (or buses) for my mix, then final group track for the instrumental, final group track for the vocals, then I route this 2 into a final Mix Group track, which I'll apply the mastering, then route it to Stereo Output. What do you think about that?
 
I use Cubase 5 myself and make all of my tracks wav, because the plug-ins I use process them better. I have the Waves Vocal Studio, and a few other Plug-ins, that are designed to manipulate wav files. I use 24bit wav files, because the samples that I use in my VST's are all 24bit. I wouldn't go less than 44.1k on the sample rate, but if you can I would go with the 48k sample rate. You should only use the 48k sample rate if the samples were recorded with that and if your session is set for that. If not 44.1k would work just fine.

Now as for the mix itself, I suggest opening a completely new session and import your audio. The settings should be at 24bit, 48k so you can process high resolution audio. Your current process sounds great. Once you complete your mix you will want to bounce everything down to 16bit 44.1k Stero because this is the format for an audio disc. I use a seprate session to mix, because when you mix a track thats all you want to focus on. If you do it in the same session that the MIDI is contained in, you will want to manipulate it at some point, and that takes away from your vision of mixing. I hope this helps. Feel free to message me if you have any more questions.
 
There is no must do anything; only personal preference on how to handle the various stages of a project.

If you can manage the process without bouncing out then leave it as is; if not then bounce each track out and start a new mix-stage project.

I too use cubase 5 and find that there is no real benefit to doing it with vsts or audio files

- the issue becomes one of knowing when to freeze certain tracks and
- whether to freeze the channel (eq and fx as well) or
- just freeze the track itself

Freezing the channel means that you cannot do any mix level work

Freezing the track renders it as audio in the project folder and allows you to continue to apply mix-stage processing to the result

If you are using the real time MIDI modifier randomisers on your midi data, then you will want to unfreeze for the final export of the mix, so as to gain back the human-like response generated by such tools
 
Thank you all so much for support. I started exporting my tracks into wave files at 32 bit and 44k before seeing this. Should I export them at 24bit and 48k for better results?

I've seen the "freezing" thing on a video a couple of months ago, actually I was thinking of it yesterday but couldn't remember where was the freezing button. I never understood these WAV settings. Can someone explain me what is bit depth, bitrate, 44k, 48k, and so on?

Last question: what do you guys use on the Master bus? I usually use a final EQ, a multiband compressor and a maximizer (usually I use the one which comes with Cubase) and I add the UV22HR although I really don't understand what it does. I simply feel like putting it there :D
 
The freeze button looks like an idealised snowflake

Bit depth
Bit depth is the ability of the stream/file to represent amplitude.

16 bit has a signal to noise ratio (SNR) or dynamic range of about 96db.

24 bit has a SNR of about 144db.

A single sample is represented by a number that is 16 bits or 24 bits long.

With the 32 bit and 64 bit formats, you are using floating point representations which provide more accurate positions but not much more in the way of SNR

Sampling rate
Sampling rate is how many samples per second: the higher the sample rate the more samples per second, the higher the Nyquist frequency, the larger the frequency range that can be represented, although after 44.1kHz, there is not much point as most humans can only hear up to 20kHz if at all (the older you get the lower this upper frequency limit is). The reasons most of the higher oversampling rates exist is to provide more accurate sample positions and to align with other standards for audio in the media industry.

Effect on file size
Make either the bit depth or the sampling rate larger and the file size increases as well

16 bits is 2 bytes per sample
24 bits is 3 bytes per sample
​

44.1kHz means 44100 samples per second which can be either 88200 bytes per second or 132300 bytes per second for a mono signal and double that for a stereo signal
48kkHz means 48000 samples per second which can be either 96000 bytes per second or 144000 bytes per second for a mono signal and double that for a stereo signal

Bit rate
bit rate is the speed at which the track plays back - it is simply a transmission speed, rather than a measure of quality

bit rate can be calculated by the following formula

number of channels x number of bits x sampling rate

so 320kbps is effectively transmitting 40000 bytes per second


16 bits 44.1kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 16 bits and a sampling rate of 44.1kHz is

number of channels x number of bits x sampling rate
= 2 channels x 16 bits x 44100Hz
= 1411200 bits per second
= 1411.2 kbps (1378.125 kbps if we use 1024 rather than 1000 as standing for k)

16 bits 48kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 16 bits and a sampling rate of 48kHz is

number of channels x number of bits x sampling rate
= 2 channels x 16 bits x 48000Hz
= 1536000 bits per second
= 1536 kbps (1500 kbps if we use 1024 rather than 1000 as standing for k)

24 bits 44.1kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 24 bits and a sampling rate of 44.1kHz is

number of channels x number of bits x sampling rate
= 2 channels x 24 bits x 44100Hz
= 2116800 bits per second
= 2116.8 kbps (2067.1875 kbps if we use 1024 rather than 1000 as standing for k)

24 bits 48kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 24 bits and a sampling rate of 48kHz is

number of channels x number of bits x sampling rate
= 2 channels x 24 bits x 48000Hz
= 2304000 bits per second
= 2304 kbps (2250 kbps if we use 1024 rather than 1000 as standing for k)
​

master buss
master buss - every track is different

Use the UV22HR only if you are exporting to 16 bit - it is a ditherer which adds digital noise to smooth out the noise floor of the exported 16 bit wav file
 
Last edited:
Damn, I always mix my VST sounds.
This is one hell of a good tip!
Thanks!
 
bandcoach said:
The freeze button looks like an idealised snowflake

Bit depth
Bit depth is the ability of the stream/file to represent amplitude.

16 bit has a signal to noise ratio (SNR) or dynamic range of about 96db.

24 bit has a SNR of about 144db.

A single sample is represented by a number that is 16 bits or 24 bits long.

With the 32 bit and 64 bit formats, you are using floating point representations which provide more accurate positions but not much more in the way of SNR

Sampling rate
Sampling rate is how many samples per second: the higher the sample rate the more samples per second, the higher the Nyquist frequency, the larger the frequency range that can be represented, although after 44.1kHz, there is not much point as most humans can only hear up to 20kHz if at all (the older you get the lower this upper frequency limit is). The reasons most of the higher oversampling rates exist is to provide more accurate sample positions and to align with other standards for audio in the media industry.
Effect on file size
Make either the bit depth or the sampling rate larger and the file size increases as well

16 bits is 2 bytes per sample
24 bits is 3 bytes per sample
​

44.1kHz means 44100 samples per second which can be either 88200 bytes per second or 132300 bytes per second for a mono signal and double that for a stereo signal
48kkHz means 48000 samples per second which can be either 96000 bytes per second or 144000 bytes per second for a mono signal and double that for a stereo signal

Bit rate
bit rate is the speed at which the track plays back - it is simply a transmission speed, rather than a measure of quality

bit rate can be calculated by the following formula

number of channels x number of bits x sampling rate

so 320kbps is effectively transmitting 40000 bytes per second

16 bits 44.1kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 16 bits and a sampling rate of 44.1kHz is

number of channels x number of bits x sampling rate
= 2 channels x 16 bits x 44100Hz
= 1411200 bits per second
= 1411.2 kbps (1378.125 kbps if we use 1024 rather than 1000 as standing for k)

16 bits 48kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 16 bits and a sampling rate of 48kHz is

number of channels x number of bits x sampling rate
= 2 channels x 16 bits x 48000Hz
= 1536000 bits per second
= 1536 kbps (1500 kbps if we use 1024 rather than 1000 as standing for k)

24 bits 44.1kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 24 bits and a sampling rate of 44.1kHz is

number of channels x number of bits x sampling rate
= 2 channels x 24 bits x 44100Hz
= 2116800 bits per second
= 2116.8 kbps (2067.1875 kbps if we use 1024 rather than 1000 as standing for k)

24 bits 48kHz stereo
the bit rate for a standard stereo wav file at a bit depth of 24 bits and a sampling rate of 48kHz is

number of channels x number of bits x sampling rate
= 2 channels x 24 bits x 48000Hz
= 2304000 bits per second
= 2304 kbps (2250 kbps if we use 1024 rather than 1000 as standing for k)
​

master buss
master buss - every track is different

Use the UV22HR only if you are exporting to 16 bit - it is a ditherer which adds digital noise to smooth out the noise floor of the exported 16 bit wav file
Click to expand...

Excuse me sir. I just reviewed your explanation (I learn by paper and pen) and I have a few questions if you don't mind:

1. Bit rate is simply a transmission of speed, rather than quality. BUT is it true that we can tell if an mp3 song for example has a better quality on a 320kbps rate, rather than a 192kbps rate, due to the fact that the bit rate formula depends on sample rate and bit depth?

2. What's the difference between normal bit rate and variable bit rate? And which is better and why?

3. I understand using a 48kHz session will allow us to have a better look of the sound and mix better, although our final export will be at 44.1 kHz. Is it right?

4. I don't think I understand if 24 bit depth means louder music, or it's more technical than that.

5. Can you explain please what is "sample" when refering to samples per second.


Thank you so much,
Chriss
 
ChrissMusic said:
I have a few questions if you don't mind:

1. Bit rate is simply a transmission of speed, rather than quality. BUT is it true that we can tell if an mp3 song for example has a better quality on a 320kbps rate, rather than a 192kbps rate, due to the fact that the bit rate formula depends on sample rate and bit depth?
Click to expand...

bit rate whilst a transmission rate is also an indirect measure of quality as you only get higher bit rates by increasing sample rates and/or bit depth

for example (a ludicrous one designed to show the folly of using bit rate as a single measure of quality but illustrates how it can be misused more than anything)

using 8 bits as the bit depth to compare with old school samplers (although these were more commonly 10 or 12 bits as the 80's wore on)

[table="class:grid, align:center"]
[tr][td]bit depth[/td][td]Discrete amplitude points
(accuracy of a single sample)[/td][td]Accuracy over 6 bits[/td][/tr]
[tr][td]6[/td][td=align:right]65[/td][td=align:right]1[/td][/tr]
[tr][td]8[/td][td=align:right]257[/td][td=align:right]4 x[/td][/tr]
[tr][td]10[/td][td=align:right]1025 [/td][td=align:right]16 x[/td][/tr]
[tr][td]12[/td][td=align:right]2049 [/td][td=align:right]32 x[/td][/tr]
[tr][td]14[/td][td=align:right]8197 [/td][td=align:right]128 x[/td][/tr]
[tr][td]16[/td][td=align:right]65537 [/td][td=align:right]1024 x[/td][/tr]
[tr][td]24[/td][td=align:right]16777217[/td][td=align:right]262144 x[/td][/tr]
[/table]

we can then compare the various bit rates we would get for the various sampling rates and bit depths in use in computer audio since the end of the 80's

[table="class:grid, align:center"]
[tr] [td=align:center] Bit Depth [/td] [td=align:center] Stereo [/td] [td=align:center] Sample Rate
(kHz) [/td] [td=align:center] Bit rate
(b/s) [/td] [td=align:center] kb/s [/td] [td=align:center] as
1024 b/s [/td] [td=align:center] Bit Depth [/td] [td=align:center] Stereo [/td] [td=align:center] Sample Rate
(kHz) [/td] [td=align:center] Bit rate
(b/s) [/td] [td=align:center] kb/s [/td] [td=align:center] as
1024 b/s [/td] [/tr]
[tr] [td=align:center] 6 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 66150 [/td] [td=align:right] 66.15 [/td] [td=align:right] 64.60 [/td] [td=align:center] 6 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 529200 [/td] [td=align:right] 529.20 [/td] [td=align:right] 516.80 [/td] [/tr]
[tr] [td=align:center] 8 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 88200 [/td] [td=align:right] 88.20 [/td] [td=align:right] 86.13 [/td] [td=align:center] 8 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 705600 [/td] [td=align:right] 705.60 [/td] [td=align:right] 689.06 [/td] [/tr]
[tr] [td=align:center] 10 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 110250 [/td] [td=align:right] 110.25 [/td] [td=align:right] 107.67 [/td] [td=align:center] 10 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 882000 [/td] [td=align:right] 882.00 [/td] [td=align:right] 861.33 [/td] [/tr]
[tr] [td=align:center] 12 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 132300 [/td] [td=align:right] 132.30 [/td] [td=align:right] 129.20 [/td] [td=align:center] 12 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 1058400 [/td] [td=align:right] 1058.40 [/td] [td=align:right] 1033.59 [/td] [/tr]
[tr] [td=align:center] 14 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 154350 [/td] [td=align:right] 154.35 [/td] [td=align:right] 150.73 [/td] [td=align:center] 14 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 1234800 [/td] [td=align:right] 1234.80 [/td] [td=align:right] 1205.86 [/td] [/tr]
[tr] [td=align:center] 16 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 176400 [/td] [td=align:right] 176.40 [/td] [td=align:right] 172.27 [/td] [td=align:center] 16 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 1411200 [/td] [td=align:right] 1411.20 [/td] [td=align:right] 1378.13 [/td] [/tr]
[tr] [td=align:center] 24 [/td] [td=align:right] 2 [/td] [td=align:right] 5.51 [/td] [td=align:right] 264600 [/td] [td=align:right] 264.60 [/td] [td=align:right] 258.40 [/td] [td=align:center] 24 [/td] [td=align:right] 2 [/td] [td=align:right] 44.10 [/td] [td=align:right] 2116800 [/td] [td=align:right] 2116.80 [/td] [td=align:right] 2067.19 [/td] [/tr]
[tr] [td=align:center] 6 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 132300 [/td] [td=align:right] 132.30 [/td] [td=align:right] 129.20 [/td] [td=align:center] 6 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 576000 [/td] [td=align:right] 576.00 [/td] [td=align:right] 562.50 [/td] [/tr]
[tr] [td=align:center] 8 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 176400 [/td] [td=align:right] 176.40 [/td] [td=align:right] 172.27 [/td] [td=align:center] 8 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 768000 [/td] [td=align:right] 768.00 [/td] [td=align:right] 750.00 [/td] [/tr]
[tr] [td=align:center] 10 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 220500 [/td] [td=align:right] 220.50 [/td] [td=align:right] 215.33 [/td] [td=align:center] 10 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 960000 [/td] [td=align:right] 960.00 [/td] [td=align:right] 937.50 [/td] [/tr]
[tr] [td=align:center] 12 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 264600 [/td] [td=align:right] 264.60 [/td] [td=align:right] 258.40 [/td] [td=align:center] 12 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 1152000 [/td] [td=align:right] 1152.00 [/td] [td=align:right] 1125.00 [/td] [/tr]
[tr] [td=align:center] 14 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 308700 [/td] [td=align:right] 308.70 [/td] [td=align:right] 301.46 [/td] [td=align:center] 14 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 1344000 [/td] [td=align:right] 1344.00 [/td] [td=align:right] 1312.50 [/td] [/tr]
[tr] [td=align:center] 16 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 352800 [/td] [td=align:right] 352.80 [/td] [td=align:right] 344.53 [/td] [td=align:center] 16 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 1536000 [/td] [td=align:right] 1536.00 [/td] [td=align:right] 1500.00 [/td] [/tr]
[tr] [td=align:center] 24 [/td] [td=align:right] 2 [/td] [td=align:right] 11.03 [/td] [td=align:right] 529200 [/td] [td=align:right] 529.20 [/td] [td=align:right] 516.80 [/td] [td=align:center] 24 [/td] [td=align:right] 2 [/td] [td=align:right] 48.00 [/td] [td=align:right] 2304000 [/td] [td=align:right] 2304.00 [/td] [td=align:right] 2250.00 [/td] [/tr]
[tr] [td=align:center] 6 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 264600 [/td] [td=align:right] 264.60 [/td] [td=align:right] 258.40 [/td] [td=align:center] 6 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 1152000 [/td] [td=align:right] 1152.00 [/td] [td=align:right] 1125.00 [/td] [/tr]
[tr] [td=align:center] 8 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 352800 [/td] [td=align:right] 352.80 [/td] [td=align:right] 344.53 [/td] [td=align:center] 8 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 1536000 [/td] [td=align:right] 1536.00 [/td] [td=align:right] 1500.00 [/td] [/tr]
[tr] [td=align:center] 10 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 441000 [/td] [td=align:right] 441.00 [/td] [td=align:right] 430.66 [/td] [td=align:center] 10 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 1920000 [/td] [td=align:right] 1920.00 [/td] [td=align:right] 1875.00 [/td] [/tr]
[tr] [td=align:center] 12 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 529200 [/td] [td=align:right] 529.20 [/td] [td=align:right] 516.80 [/td] [td=align:center] 12 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 2304000 [/td] [td=align:right] 2304.00 [/td] [td=align:right] 2250.00 [/td] [/tr]
[tr] [td=align:center] 14 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 617400 [/td] [td=align:right] 617.40 [/td] [td=align:right] 602.93 [/td] [td=align:center] 14 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 2688000 [/td] [td=align:right] 2688.00 [/td] [td=align:right] 2625.00 [/td] [/tr]
[tr] [td=align:center] 16 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 705600 [/td] [td=align:right] 705.60 [/td] [td=align:right] 689.06 [/td] [td=align:center] 16 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 3072000 [/td] [td=align:right] 3072.00 [/td] [td=align:right] 3000.00 [/td] [/tr]
[tr] [td=align:center] 24 [/td] [td=align:right] 2 [/td] [td=align:right] 22.05 [/td] [td=align:right] 1058400 [/td] [td=align:right] 1058.40 [/td] [td=align:right] 1033.59 [/td] [td=align:center] 24 [/td] [td=align:right] 2 [/td] [td=align:right] 96.00 [/td] [td=align:right] 4608000 [/td] [td=align:right] 4608.00 [/td] [td=align:right] 4500.00 [/td] [/tr]
[/table]

as you can see a bit depth of 6 bits at standard sample rates (44.1kHz and above) achieves a better transmission rate than the best available with mp3 (529.2kb/s vs 320kb/s)

2. What's the difference between normal bit rate and variable bit rate? And which is better and why?
Click to expand...

I would class these as Constant bit rate (CBR) vs Variable bit rate (VBR)

A constant bit rate should be preferred in almost every situation.

Constant bit rate is exactly what it sounds like: the bit rate does not change during the transmission of the file

Variable bit rate uses an algorithm (process or procedure) to use a lower bit rate for simple content, say silence, and higher bit rates for more complex sounds

This will give the file an average bit rate, calculated by adding all the bit rates divided by the time each is operating to find the final average bit rate (ABR)

3. I understand using a 48kHz session will allow us to have a better look of the sound and mix better, although our final export will be at 44.1 kHz. Is it right?
Click to expand...

48kHz is industry standard for sharing broadcast quality audio; 44.1kHz is the CD-Audio standard defined at the start of the 1980's by Phillips and Sony

4. I don't think I understand if 24 bit depth means louder music, or it's more technical than that.
Click to expand...

24 bit bit depth is about having more amplitude points available not about having louder audio - it means that we can dissect the audio to a finer degree of representation

Recasting the table above into a comparison of the integer based bit depth amplitudes, we can seethe meaning of the various bit depths previously discussed

[table="class:grid, align:center"]
[tr][td=align:center]Bit depth[/td][td=align:center]6[/td][td=align:center]8[/td][td=align:center]10[/td][td=align:center]12[/td][td=align:center]14[/td][td=align:center]16[/td][td=align:center]24[/td][/tr]
[tr][td=align:center]6[/td][td=align:right]1[/td][td=align:right]4[/td][td=align:right]16[/td][td=align:right]64[/td][td=align:right]256[/td][td=align:right]1024[/td][td=align:right]262144[/td][/tr]
[tr][td=align:center]8[/td][td=align:right]-[/td][td=align:right]1[/td][td=align:right]4[/td][td=align:right]16[/td][td=align:right]64[/td][td=align:right]256[/td][td=align:right]65536[/td][/tr]
[tr][td=align:center]10[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]1[/td][td=align:right]4[/td][td=align:right]16[/td][td=align:right]64[/td][td=align:right]16384[/td][/tr]
[tr][td=align:center]12[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]1[/td][td=align:right]4[/td][td=align:right]16[/td][td=align:right]4096[/td][/tr]
[tr][td=align:center]14[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]1[/td][td=align:right]4[/td][td=align:right]1024[/td][/tr]
[tr][td=align:center]16[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]1[/td][td=align:right]256[/td][/tr]
[tr][td=align:center]24[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]-[/td][td=align:right]1[/td][/tr]
[/table]

As we move across our range of bit depths we can see that the increase of amplitude points leads to many more levels of amplitude that can be represented by each in comparison to the smaller bit depths - think of it as as the bit depth increases so does the resolution of the audio amplitudes being recorded - for each step in a lower bit depth there are many more steps available in a higher resolution

5. Can you explain please what is "sample" when refering to samples per second.
Click to expand...

A sample is a single snapshot of the audio amplitude at that position in the sequence of samples.

To represent audio across the range of human hearing (20Hz-20kHz) we need a sample rate that is at least twice as high as the highest frequency to accurately represent all of those frequencies.

So most sampling rates are set above 40kHz. 44.1kHz was selected as its half-rate, 22.05kHz was sufficiently above the upper limit of 20kHz
 
bandcoach said:
bit rate whilst a transmission rate is also an indirect measure of quality as you only get higher bit rates by increasing sample rates and/or bit depth

for example (a ludicrous one designed to show the folly of using bit rate as a single measure of quality but illustrates how it can be misused more than anything)

using 8 bits as the bit depth to compare with old school samplers (although these were more commonly 10 or 12 bits as the 80's wore on)

[TABLE="class: grid, align: center"]
[TR]
[TD]bit depth[/TD]
[TD]Discrete amplitude points
(accuracy of a single sample)[/TD]
[TD]Accuracy over 6 bits[/TD]
[/TR]
[TR]
[TD]6[/TD]
[TD="align: right"]65[/TD]
[TD="align: right"]1[/TD]
[/TR]
[TR]
[TD]8[/TD]
[TD="align: right"]257[/TD]
[TD="align: right"]4 x[/TD]
[/TR]
[TR]
[TD]10[/TD]
[TD="align: right"]1025[/TD]
[TD="align: right"]16 x[/TD]
[/TR]
[TR]
[TD]12[/TD]
[TD="align: right"]2049[/TD]
[TD="align: right"]32 x[/TD]
[/TR]
[TR]
[TD]14[/TD]
[TD="align: right"]8197[/TD]
[TD="align: right"]128 x[/TD]
[/TR]
[TR]
[TD]16[/TD]
[TD="align: right"]65537[/TD]
[TD="align: right"]1024 x[/TD]
[/TR]
[TR]
[TD]24[/TD]
[TD="align: right"]16777217[/TD]
[TD="align: right"]262144 x[/TD]
[/TR]
[/TABLE]

we can then compare the various bit rates we would get for the various sampling rates and bit depths in use in computer audio since the end of the 80's

[TABLE="class: grid, align: center"]
[TR]
[TD="align: center"] Bit Depth [/TD]
[TD="align: center"] Stereo [/TD]
[TD="align: center"] Sample Rate
(kHz) [/TD]
[TD="align: center"] Bit rate
(b/s) [/TD]
[TD="align: center"] kb/s [/TD]
[TD="align: center"] as
1024 b/s [/TD]
[TD="align: center"] Bit Depth [/TD]
[TD="align: center"] Stereo [/TD]
[TD="align: center"] Sample Rate
(kHz) [/TD]
[TD="align: center"] Bit rate
(b/s) [/TD]
[TD="align: center"] kb/s [/TD]
[TD="align: center"] as
1024 b/s [/TD]
[/TR]
[TR]
[TD="align: center"] 6 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 66150 [/TD]
[TD="align: right"] 66.15 [/TD]
[TD="align: right"] 64.60 [/TD]
[TD="align: center"] 6 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 529200 [/TD]
[TD="align: right"] 529.20 [/TD]
[TD="align: right"] 516.80 [/TD]
[/TR]
[TR]
[TD="align: center"] 8 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 88200 [/TD]
[TD="align: right"] 88.20 [/TD]
[TD="align: right"] 86.13 [/TD]
[TD="align: center"] 8 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 705600 [/TD]
[TD="align: right"] 705.60 [/TD]
[TD="align: right"] 689.06 [/TD]
[/TR]
[TR]
[TD="align: center"] 10 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 110250 [/TD]
[TD="align: right"] 110.25 [/TD]
[TD="align: right"] 107.67 [/TD]
[TD="align: center"] 10 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 882000 [/TD]
[TD="align: right"] 882.00 [/TD]
[TD="align: right"] 861.33 [/TD]
[/TR]
[TR]
[TD="align: center"] 12 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 132300 [/TD]
[TD="align: right"] 132.30 [/TD]
[TD="align: right"] 129.20 [/TD]
[TD="align: center"] 12 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 1058400 [/TD]
[TD="align: right"] 1058.40 [/TD]
[TD="align: right"] 1033.59 [/TD]
[/TR]
[TR]
[TD="align: center"] 14 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 154350 [/TD]
[TD="align: right"] 154.35 [/TD]
[TD="align: right"] 150.73 [/TD]
[TD="align: center"] 14 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 1234800 [/TD]
[TD="align: right"] 1234.80 [/TD]
[TD="align: right"] 1205.86 [/TD]
[/TR]
[TR]
[TD="align: center"] 16 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 176400 [/TD]
[TD="align: right"] 176.40 [/TD]
[TD="align: right"] 172.27 [/TD]
[TD="align: center"] 16 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 1411200 [/TD]
[TD="align: right"] 1411.20 [/TD]
[TD="align: right"] 1378.13 [/TD]
[/TR]
[TR]
[TD="align: center"] 24 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 5.51 [/TD]
[TD="align: right"] 264600 [/TD]
[TD="align: right"] 264.60 [/TD]
[TD="align: right"] 258.40 [/TD]
[TD="align: center"] 24 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 44.10 [/TD]
[TD="align: right"] 2116800 [/TD]
[TD="align: right"] 2116.80 [/TD]
[TD="align: right"] 2067.19 [/TD]
[/TR]
[TR]
[TD="align: center"] 6 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 132300 [/TD]
[TD="align: right"] 132.30 [/TD]
[TD="align: right"] 129.20 [/TD]
[TD="align: center"] 6 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 576000 [/TD]
[TD="align: right"] 576.00 [/TD]
[TD="align: right"] 562.50 [/TD]
[/TR]
[TR]
[TD="align: center"] 8 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 176400 [/TD]
[TD="align: right"] 176.40 [/TD]
[TD="align: right"] 172.27 [/TD]
[TD="align: center"] 8 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 768000 [/TD]
[TD="align: right"] 768.00 [/TD]
[TD="align: right"] 750.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 10 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 220500 [/TD]
[TD="align: right"] 220.50 [/TD]
[TD="align: right"] 215.33 [/TD]
[TD="align: center"] 10 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 960000 [/TD]
[TD="align: right"] 960.00 [/TD]
[TD="align: right"] 937.50 [/TD]
[/TR]
[TR]
[TD="align: center"] 12 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 264600 [/TD]
[TD="align: right"] 264.60 [/TD]
[TD="align: right"] 258.40 [/TD]
[TD="align: center"] 12 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 1152000 [/TD]
[TD="align: right"] 1152.00 [/TD]
[TD="align: right"] 1125.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 14 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 308700 [/TD]
[TD="align: right"] 308.70 [/TD]
[TD="align: right"] 301.46 [/TD]
[TD="align: center"] 14 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 1344000 [/TD]
[TD="align: right"] 1344.00 [/TD]
[TD="align: right"] 1312.50 [/TD]
[/TR]
[TR]
[TD="align: center"] 16 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 352800 [/TD]
[TD="align: right"] 352.80 [/TD]
[TD="align: right"] 344.53 [/TD]
[TD="align: center"] 16 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 1536000 [/TD]
[TD="align: right"] 1536.00 [/TD]
[TD="align: right"] 1500.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 24 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 11.03 [/TD]
[TD="align: right"] 529200 [/TD]
[TD="align: right"] 529.20 [/TD]
[TD="align: right"] 516.80 [/TD]
[TD="align: center"] 24 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 48.00 [/TD]
[TD="align: right"] 2304000 [/TD]
[TD="align: right"] 2304.00 [/TD]
[TD="align: right"] 2250.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 6 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 264600 [/TD]
[TD="align: right"] 264.60 [/TD]
[TD="align: right"] 258.40 [/TD]
[TD="align: center"] 6 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 1152000 [/TD]
[TD="align: right"] 1152.00 [/TD]
[TD="align: right"] 1125.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 8 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 352800 [/TD]
[TD="align: right"] 352.80 [/TD]
[TD="align: right"] 344.53 [/TD]
[TD="align: center"] 8 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 1536000 [/TD]
[TD="align: right"] 1536.00 [/TD]
[TD="align: right"] 1500.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 10 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 441000 [/TD]
[TD="align: right"] 441.00 [/TD]
[TD="align: right"] 430.66 [/TD]
[TD="align: center"] 10 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 1920000 [/TD]
[TD="align: right"] 1920.00 [/TD]
[TD="align: right"] 1875.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 12 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 529200 [/TD]
[TD="align: right"] 529.20 [/TD]
[TD="align: right"] 516.80 [/TD]
[TD="align: center"] 12 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 2304000 [/TD]
[TD="align: right"] 2304.00 [/TD]
[TD="align: right"] 2250.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 14 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 617400 [/TD]
[TD="align: right"] 617.40 [/TD]
[TD="align: right"] 602.93 [/TD]
[TD="align: center"] 14 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 2688000 [/TD]
[TD="align: right"] 2688.00 [/TD]
[TD="align: right"] 2625.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 16 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 705600 [/TD]
[TD="align: right"] 705.60 [/TD]
[TD="align: right"] 689.06 [/TD]
[TD="align: center"] 16 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 3072000 [/TD]
[TD="align: right"] 3072.00 [/TD]
[TD="align: right"] 3000.00 [/TD]
[/TR]
[TR]
[TD="align: center"] 24 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 22.05 [/TD]
[TD="align: right"] 1058400 [/TD]
[TD="align: right"] 1058.40 [/TD]
[TD="align: right"] 1033.59 [/TD]
[TD="align: center"] 24 [/TD]
[TD="align: right"] 2 [/TD]
[TD="align: right"] 96.00 [/TD]
[TD="align: right"] 4608000 [/TD]
[TD="align: right"] 4608.00 [/TD]
[TD="align: right"] 4500.00 [/TD]
[/TR]
[/TABLE]

as you can see a bit depth of 6 bits at standard sample rates (44.1kHz and above) achieves a better transmission rate than the best available with mp3 (529.2kb/s vs 320kb/s)



I would class these as Constant bit rate (CBR) vs Variable bit rate (VBR)

A constant bit rate should be preferred in almost every situation.

Constant bit rate is exactly what it sounds like: the bit rate does not change during the transmission of the file

Variable bit rate uses an algorithm (process or procedure) to use a lower bit rate for simple content, say silence, and higher bit rates for more complex sounds

This will give the file an average bit rate, calculated by adding all the bit rates divided by the time each is operating to find the final average bit rate (ABR)



48kHz is industry standard for sharing broadcast quality audio; 44.1kHz is the CD-Audio standard defined at the start of the 1980's by Phillips and Sony



24 bit bit depth is about having more amplitude points available not about having louder audio - it means that we can dissect the audio to a finer degree of representation

Recasting the table above into a comparison of the integer based bit depth amplitudes, we can seethe meaning of the various bit depths previously discussed

[TABLE="class: grid, align: center"]
[TR]
[TD="align: center"]Bit depth[/TD]
[TD="align: center"]6[/TD]
[TD="align: center"]8[/TD]
[TD="align: center"]10[/TD]
[TD="align: center"]12[/TD]
[TD="align: center"]14[/TD]
[TD="align: center"]16[/TD]
[TD="align: center"]24[/TD]
[/TR]
[TR]
[TD="align: center"]6[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]16[/TD]
[TD="align: right"]64[/TD]
[TD="align: right"]256[/TD]
[TD="align: right"]1024[/TD]
[TD="align: right"]262144[/TD]
[/TR]
[TR]
[TD="align: center"]8[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]16[/TD]
[TD="align: right"]64[/TD]
[TD="align: right"]256[/TD]
[TD="align: right"]65536[/TD]
[/TR]
[TR]
[TD="align: center"]10[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]16[/TD]
[TD="align: right"]64[/TD]
[TD="align: right"]16384[/TD]
[/TR]
[TR]
[TD="align: center"]12[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]16[/TD]
[TD="align: right"]4096[/TD]
[/TR]
[TR]
[TD="align: center"]14[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]4[/TD]
[TD="align: right"]1024[/TD]
[/TR]
[TR]
[TD="align: center"]16[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]1[/TD]
[TD="align: right"]256[/TD]
[/TR]
[TR]
[TD="align: center"]24[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]-[/TD]
[TD="align: right"]1[/TD]
[/TR]
[/TABLE]

As we move across our range of bit depths we can see that the increase of amplitude points leads to many more levels of amplitude that can be represented by each in comparison to the smaller bit depths - think of it as as the bit depth increases so does the resolution of the audio amplitudes being recorded - for each step in a lower bit depth there are many more steps available in a higher resolution



A sample is a single snapshot of the audio amplitude at that position in the sequence of samples.

To represent audio across the range of human hearing (20Hz-20kHz) we need a sample rate that is at least twice as high as the highest frequency to accurately represent all of those frequencies.

So most sampling rates are set above 40kHz. 44.1kHz was selected as its half-rate, 22.05kHz was sufficiently above the upper limit of 20kHz
Click to expand...


Thank you, sir. You have my respect.
Can I ask for some feedback on my latest song? :)

https://www.youtube.com/watch?v=lvp8LjdNfNQ
 
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