Re: [Harp-L] home recording

[John Shirley <john_shirley@xxxxxxx>]

Hey all.

I wrote a series of articles for Recording Magazine a few years back on home recording topics, and then redid them as web versions. There are 26 articles, including media, available for free at:

http://www.recordingmag.com/?do=resources&cat=113&page=3

I did not do an article specifically on recording for Harmonica, but I am certainly considering it now…. (I've only started playing since completing the series)

Anyway, I hope there's some helpful info in there for some of you.

(articles 3 and 4 may help with the bit depth vs sample rate discussion)

Enjoy.

- John


> On Dec 6, 2013, at 8:42 PM, "harp" <harp@xxxxxxxxx> wrote:
> 
> Hi Larry,
> 
> These numbers, whether 44, 33, 44.1, 24, etc. all refer to the number of
> THOUSANDS of samples taken of an analog audio waveform per second during
> the analog-to-digital conversion that takes place in every modern audio
> recording and reproducing device.  For example, 44.1 kHz = 44,100 cycles
> per second.  Early on in the move from analog to digital recording there
> was a LOT of debate about how finely you have to sample analog audio in
> order to fool the human psycho-auditory system (the combination of our ear
> drums, nerves and what our brain does during the process of sound
> perception) into thinking that the diced up step-wise reproduction of a
> sound was equivalent to the smooth analog wave produced by nature.  This
> guy named Harry Nyquist came up with a rate, now known as the Nyquist Rate
> which says, if you want to reproduce a frequency of whatever, then you
> have to sample at a frequency of at least two times the original.  When
> manufacturers were coming up with the standard for Compact Disks, they
> settled on a sampling frequency of 44.1 kHz.  Seems logical - most audio
> systems need to pass from some lower frequency, say 20 Hz up to 20 kHz.
> Humm - 20 kHz x2 = 40 kHz.  A little extra headroom plus a little fudging
> for some of those psycho-auditory characteristics I mentioned earlier and
> bingo - 44.1.
> 
> What happens if you under-sample, say at 24 kHz?  Short answer is you
> start perceiving artifacts.  But unless you are in a quiet room with a
> really good system, you probably will never hear it. (Audio purists, feel
> free to flame away).
> 
> As for 33 kHz, never heard of it, but I have a Zoom, and perhaps for some
> reason it is one of the settings - I will have to check.  Frankly, people
> who write standards for stuff frequently put in all sorts of corner cases.
> Then the industry settles around some common numbers and people move on.
> Don??t know, but if I was guessing, I would say that is what the deal is
> with 33.
> 
> Brad
> 
>> On 12/6/13, 8:16 PM, "Richard Hunter" <turtlehill@xxxxxxxxxxxxx> wrote:
>> 
>> Larry Sandy wrote:
>> <Our sound department supervisor recently presented a talk on recording
>> and related topics.  He said about 33 bit sampling was <enough and that
>> 44 bit samples were superfluous.  I'm confused. Maybe he was actually
>> discussing another topic.  I understood bit sampling to mean the number
>> of digital samples during one cycle on the waveform monitor.  I think
>> most in attendance were lost right after his introduction.  Home
>> recording is an interesting topic so please keep it going.
>> 
>> Larry, I have never heard of 33-bit and 44-bit sampling.  Most pro audio
>> is originally recorded with a bit depth of 24 bits, which is reduced to
>> 16 bits for commercial CD releases.
>> 
>> I think your sound department supervisor was referring to the sampling
>> RATE, i.e. how frequently the audio stream is sampled.  44.1 kHz, 48 kHz,
>> or 96 kHz are the industry standards here.  The only device I've ever
>> seen with a 33 kHz sampling rate was the Zoom PS-02, which I would not
>> describe as a CD-quality recording device. The point is moot, anyway,
>> since I doubt that a 33 kHz audio interface is now for sale anywhere in
>> the world (unless somebody is blowing out a supply of PS-02s somewhere--I
>> sold one a while ago).
>> 
>> Given that there are no audio interfaces out there that work at 33 kHz, I
>> have no idea how your sound department supervisor formed his opinion.
>> But like I said, it doesn't matter if he's right or wrong, since as a
>> practical matter almost nobody reading this will ever see or hear a
>> device that records audio at less than a 44.1 kHz sampling rate.
>> 
>> Thanks, Richard Hunter
>> 
>> author, "Jazz Harp" (Oak Publications, NYC)
>> Latest mp3s and harmonica blog at http://hunterharp.com
>> Vids at http://www.youtube.com/user/lightninrick
>> Twitter: lightninrick
>