Re: [Denemo-devel] hum on the mic input

[Richard Shann]

On Fri, 2008-09-12 at 21:28 +0200, Nils Gey wrote:

> 
> Well, I would not say its an overkill. If you are seriously in music one day
>  you want to have this or that detail and then you have to get a better card 
> anyway. 
Yes, I cannot imagine ever wanting to work with large scores, or listen
to more than one or two parts at a time (I am only listening for
mistakes in my inputting of the music), but having some extras is better
than not as you never know the future. (On the other hand the equipment
will be out of date when that happens).
> The point is not the sound quality, its the latency. If you have large scores 
> then you will get latency, 
> especially when the music gets fast, lot of 16th notes for example. If you 
> want to actually record Midi signals, not just enter them note for note its 
> highly important to have low latency. The timing is just better with a good 
> card. And if you want your playback to sound good, for example with 
> orchestral samples, then you need a good card anyway.
> 
> > Can you send a link to a site that lists linux comaptible midi stuff?
> > Thanks for your help.
> > Richard
> 
> First place is the ALSA Database: http://www.alsa-project.org/main/index.php/ 
> . 
I find this site impossible to use. For example, I recognize the name
"creative labs" (because it is written on my loudspeakers) and I follow
it to a page that says "Sound Blaster xxx" with MIDIio marked but when I
follow the links, the soundcards in question have no midi ports on them.
I think you would have had to have found a device first, which you could
then look up to see if ALSA supported it.
I did come across a midi to usb device on the Maplins site for about 60
euros, but there was no model number or brand name to check out ALSA
compatibility... And there is not so much difference in price between
that and the audiophile 2469 card.

> For the midi chain the only thing that matters is the soundcard. 
> If you have not a laptop I really suggest a PCI card since its just better 
> and mostly cheaper then USB.
>  I do the research for good cards from time to time an the M-Audio Delta 
> Audiophile 2469 beats them all.
I was disappointed not to find a figure for the input impedance on the
technical specs of this card: while I have no immediate interest in any
of the issues around latency, or sound quality, I am interested in
making recordings of our performances. And, as I have discovered
standard dynamic microphones do not put out a strong enough signal to
drive the mic input of typical soundcards. (The mic I have is a Yamaha
YM70S). From the fact that the M-Audio site has a pre-amp advertised
immediately below the audiophile card, I guess this applies to their
card as well.
So it may be that all I need for getting the notes into Denemo reliably
is a pre-amp (and the Aubio note detection software which I have already
wired in). 
> 
> One thing that has not been mentioned yet is the linux distribution or the 
> kernel. 
> There are some good Audio Distributions out there. Ubuntustudio(Ubuntu), 
> 64Studio(Debian) and Jacklab/JAD(OpenSuse) 
> (all in 32bit and 64bit) all have a real time kernel compiled in and a 
> preconfigured JACK System 
> where you can connect all the programms together and route midi and audio 
> streams without latency loss between them. 
> If you want to develop Denemo to more Midi then you might want a proper 
> Enviroment, which are these Distributions.
Well, developing in a less advanced environment would have the advantage
that it would likely work for everyone, not just those with specialized
distributions? I would just be picking up pitches from the midi and
using them in place of the detected notes that aubio gets at the moment.

I'll see about getting a mixer/pre-amp next I think, as this might do
everything I need. (Perhaps I should add, I am interested in recording
our live performances just for learning purposes - it's easier to hear
faults in performance if you are sitting back and listening! I didn't
want to make a CD)

Richard