12 bit & 16 bit - Noticeable quality difference?

[James Emory]

I have never recorded in 12 bit audio with the XL-1 and want to know if there is a noticeable difference in 12 bit and 16 bit audio by someone who specializes in audio. I did plug a mic into my camera while in 12 bit and monitored with headphones and it sounded just as full and clear as 16 bit. Also, I can understand why audio has to be 12 bit in order to be able to provide ST 1 & ST 2 (adding two channels) in the menu but why is it an option for just ST-1 too? Who would choose supposed lower quality for stereo sound when they could just use 16 bit stereo? In other words, other than different bit rates, what is the difference between 16 bit stereo and 12 bit stereo. You're not saving on tape usage (space) so what's the point of using 12 bit stereo.

Oops. I just got this message from Don Palomaki:

"4-channel is 12-bit and sampled at 32 kHz (roughly FM broadcast
quality potential with a ~15 kHz upper frequency limit) while
2-channel is commopnly 16-bit and samples at 48 kHz (with an ~22 kHz
upper frequency limit, which could be better than CD quality).
However, most epeople will not hear the difference due to limitations
of microphones, preamp and venue noise floor, and limitations of
typical playback systems, especially with dialog."

[Don Palomaki]

Note that some DV camcorders default 2-channel recording at 12-bit, 32 kHz sample rate. User had to manually select 16-bit mode if they wanted to use it.

I believe that the discontinued VX1000 was one example. Reason was probably to allow dubbing to the second channels later. A seldom used feature in this day of low cost NLE systms.

As I understand it, the 12-bit audio mode uses some compression to obtain about the same dynamic range of 16-bit. Worth noting that the Stereo HiFi digital audio (PCM) channels on Sony's Hi8 system used something like 10-bit recording.

[Stephen Finton]

Recording ST1 in 12bit now allows you to overdub narration or commentary to ST2 later. That is why your camera allows you the option of just recording 2 channel @ 12bit.

[James Emory]

Thanks Stephen. How would you go back and record audio on those additional channels later without recording over the original audio and video? I guess that recording in 12 bit with 3-4 channels could allow you to record notes for documentation, commentary or even language translation in real time as the native language was being recorded.

Okay, I just thought of this after writing the above. I guess using an audio dub feature on the camera or deck would be the answer to preserving the original content. I have just never seen the need to do this because of NLEs.

[Don Palomaki]

Per our sidebar e-mail exchanges:

The audio rates used are based on the DV specification and the bandwidth allocated on the tape for audio. 4 channels at 12-bit and 32 kHz equals the data rate of 2 channels at 16-bit and 48 kHz.

The DV spec was probably finalized back in the early to mid 1990s, when the 80486 chip ruled and 200 megabytes was considered a huge hard drive. That is to say when linear editing was the norm and before the prospect of meaningful home NLE was a reality.

Note also that the DV spec also provides for a 16-bit, 44.1 kHz audio
(same as audio CD) but to my knowledge it has notr been used in camcorders as a record option, although it is supported for playback in the XL1 (and many other DV devices).

[Jeff Mayne]

So what is the better frequency to record audio in 12bit or 16 bit? I want to be able to add voice overs during editing. I am using the on board mic provided on the XL1s and will be adding wireless at a later date! Thanks,

[Don Palomaki]

If you want to add the additional audio to the SAME TAPE at a later time, use 12-bit. Otherwise you are probably better off these days to use 16-bit audio and add the additional audio in post.

Note that some NLE have difficulty with 4-channel audio.

[Jeff Mayne]

So if I use 16 bit I can add audio within Adobe as a wav or midi file? Thanks for being patient with me Don!

[Don Palomaki]

Yes. You can add additional audio tracks in most NLE programs, including Premiere. And you can use the audio tools in the NLE to adjust levels, left-right balance, etc.

[Waldemar Winkler]

Originally Posted by Jeff Mayne

So what is the better frequency to record audio in 12bit or 16 bit? I want to be able to add voice overs during editing. I am using the on board mic provided on the XL1s and will be adding wireless at a later date! Thanks,

I'd stay with 16 bit for your original camera recording, because most NLE systems default to that setting. These same NLE's support a lot of other audio formats, often automatically making the necessary conversions upon import. Also, most NLE's allow for direct voice-over recording, anyway.

The decision is, of course, yours. Sticking to default settings will make your editing tasks easier. It is one of those natural by-products of the editing process. I'm sure that is why Shiner Beer has a banner ad at the top of page I am currently using as I reply.

[Jeff Mayne]

Now if I add my Sennheiser wireless mics to the stock mic on my Canon XL1 I can still record in 16 bit, or do I need to switch it back to 12 bit st-1 and st-2

[Don Palomaki]

If you want to record from 4 channels (two wireless and the stock stereo mic) you have to use 12-bit mode with ST-1 and ST-2. If you want 16-bit recording, you will need to mix the four channels of sources down to two channels using an external mixer, and that may require some adapters for the XL standard mic (if you intend to use it) to ensure it gets power as swell as coupling the signal to your mixer.

[Jeff Mayne]

Ok, I do mean to be stupid here but I want to be sue I am doing this right... I have the MA-100, stock XL1S Mic, and a Sennheiser wireless mic, I have the MA-100 hooked up to the wireless recevier and so i set the audio to 12 bit st1 and st2, and the stock mic will record on one channel, and the wireless will record on the other. Correct?

[Greg Boston]

Originally Posted by Jeff Mayne

I have the MA-100 hooked up to the wireless recevier and so i set the audio to 12 bit st1 and st2, and the stock mic will record on one channel, and the wireless will record on the other. Correct?

Nope, in the scenario you describe, the on camera mic will record onto channels 1 & 2. The wireless would be recording on channel 3 and channel 4 would be empty.

-gb-

[Jeff Mayne]

So what is my best bet than? still 16bit? This is confusing I am sorry!