[linux-audio-user] [OT] Sound service and recording

[Brett McCoy]

Carotinho wrote:

> But I need your knowledge, and I don't know where else to ask!:)
> 
> So, my question is divided in 2 parts.
> 
> 1) I have to provide the sound service for an amateur rock band. The problems 
> are the following:
>  - We have a pretty good 24 ch. mixer, but the only option is to plug every 
> instrument directly to the mixer. Is this right for instruments like basses, 
> or electric guitar, or what else?

It depends on the music and the venue.  If possible, using amplifiers 
for the guitar and bass is more ideal -- the musicians will have more 
control over their sound and not have to rely on the sound person, and 
this is a good thing.  It also depends on how powerful your PA is...  to 
get a good bass sound through a PA, you will need to push the PA up 
pretty hot, and it can easily overdrive the speakers.

(BTW, I am a lead guitarist so I am speaking from this POV)

>  - What's the difference between having a cable from the electric guitar 
> amplifier line output and instead putting a microphone in front of it?

A lot!  Using a microphone picks up the sound of the amplifier much 
better, especially coupled with with room acoustics and the speaker 
cabinet.  A lot of the sound of the amp comes from the speaker (or 
speakers), and guitarists in particular are picky about the speakers in 
their amps -- using the line out of the amp bypasses the speaker and yo 
just get the raw sound, whihc can be somewhat harsh and without a lot of 
presence.

The same may go for basses also...

Now, some musicians use modeling equipment, like the PODxt series, which 
do a fairly decent job of emulating amp/speaker/microphone combinations 
and you can use those direct into the board (although experience has 
shown it still isn't as good as a real amp -- I use one myself, and 
bypass the cabinet/mike emulation).

>  - Since I believe we wont' have proper drums mic, but only a panoramic one 
> and two or more "icecream" mics (I don't know the proper english words, I 
> hope you understand), which is the best way to displace them around the 
> drums?

You mean an omnidirectional versus cardioid?  Miking drums is an art 
itself, and unless you are in a large hall or recording, miking the 
drums is not usually necessary.  There are customized kits for miking 
drums, and they have specialized mikes for the kick, snare, etc.

You'll just have to experiment with the mikes you have if you really 
want to use them for getting the drum into the PA.  Two dynamic mikes 
placed up high over the left and right of the kit is a start...

>  -  The mixer has for every channel a Canon or alternatively a Jack input. 
> What are they meant for? That is, is a Canon connection more suited e.g. to 
> mics, or what else?

Canon input?  Jack input?  Usually, the mixer will have a microphone 
(low-level --> mike pre-amp, this is usually a three-prong XLR) and a 
line-level input (1/4" jack).  Some mixers may have two mike inputs, one 
is balanced (XLR) and one is unbalanced.  You really need to refer to 
your mixer documentation for the details.

Some mixers also have inserts, which can be used for external 
processers, like perhaps a compressor for vocals.

> 2) Another job I have to do is to record a wind band playing live (40 players, 
> more or less), with 2 panoramic mics, with nothing more than a SbLive, 
> receiving mixer output, and Audacity (of course the system is a Slackware 
> Linux, so this is not really OT...:)

I'd get a better soundcard...

I recently recorded several bands live using two dynamic mikes placed to 
the left and right and somewhat behind the audience, going into a small 
pre-amp and then into a dedicated DAT deck.  We miked everything 
(including the drums) to ensure we got a good mix out of the PA, and the 
recording came out *fantastic* -- far better than what our soundperson 
had gotten recording directly from the mixer.  I am taking the DAT 
digital out and then transferring to the hard drive via Ardour, for 
editing and then through Jamin for pre-mastering.

>  - Apart from trying to avoid clipping when recording, do I need to set some 
> eq right in the mixer, or is this a job that can be safely done in 
> "post-production"?

Depends on what you have on-hand for recording.  I tend to record 
everything flat and tweak it in post.

>  - Which settings should I use for recording? I mean, 48Khz, 32 bit float, or 
> so, considering the audio card I'm using?

Also depends on what you've got on hand.  Does SBLIve support 48kHz 
recording?

> I wonder if it's worth trying recording also the rock band, without a 
> multitrack system... 

You can do it live, but if you want a studio recording, you will want to 
go with multi-track recording (using Ardour).

-- Brett
-----------
Programmer by day, Guitarist by Night
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