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

On Tue, Jul 05, 2005 at 08:01:25PM +0200, Carotinho wrote:
> Hi!
>
> I'm new to this list, I've been lurking for some weeks, and I'm sorry to begin
> with an OT...:)
>
> 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?
>
> - What's the difference between having a cable from the electric guitar
> amplifier line output and instead putting a microphone in front of it?

Mostly a big difference in frequency response. The guitar amp speaker
typically has resonant humps in the midbass and upper-midrange region,
and then rapidly plummets towards zero above approx. 4 kHz.
If you take a direct signal from the guitar amp, the recorded
signal will sound odd for clean sounds (hard to describe, it
just sounds weird and "artificial"); and simply awful for distorted
sounds (a nasty synthetic buzz).

There are "cabinet simulator" boxes on the market - built in
to various things such as Sansamp and. also available built in to some
DI boxes. If you really cannot get hold of a mic for the guitar amp,
you should strongly consider such a device.

For bass guitar, you can get away with recording direct.
It's not my preference, but many engineers prefer it.
If a compressor is available, e.g. as a foot pedal or built in
to the bass amp, use it.

> - 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?

I don't know what you mean by a panoramic mic. Omnidirectional?

By "ice cream" I presume you mean something like the Shure SM-58 or one
of the many imitations:
http://www.shure.com/microphones/models/sm58.asp

In any case, my preferred minimalistic mic arrangements are:

* two mics, approach A:

- One a foot or so over the drummer's head, aimed at the snare -
this picks up the overall sound.
- One in front of the kick drum - this adds some kick drum which is
typically weak in the overhead mic.

This gives a good overall sound, but it's basically mono, not stereo.

OR

* two mics, approach B:

both mics in an "X-Y" arrangement a few feet in front of the kit,
about three feet off the ground. This gives a nice overall sound and
good stereo image, but the snare can sound weak.

* Three mics:

- Two mics a foot or so over the drummer's head, in an X/Y arrangement,
centered on the snare drum.
- The third mic in front of the kick drum.

* Four mics:

- One a few feet over the left hand side of the kit
- One a few feet over the right side of the kit
- One in front of the kick drum
- One close up on the snare drum

Anything more than that is, frankly, just asking for trouble
until you get much more experience and much better microphones.
I'd rather record drums with three good mics than ten crappy mics.

> - 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?

I'm not familiar with the term "canon" in this context.
 
> 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...:)
> - 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"?

I'd leave EQ alone and do 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?

Generally either:
a) the highest specs your card can support, or
b) the specs you're going to end up with (e.g. for CD, 44100 / 16 /
stereo).

pick one or the other; at this level of experience and equipment,
it's frankly not worth worrying about.
 
> I wonder if it's worth trying recording also the rock band, without a
> multitrack system...

Difficult, but can be done, and well worth the learning experience
in my opinion. Just be prepared for the possibility that your
initial efforts may sound very amateurish. We all start somewhere.
And sometimes even rank amateurs get lucky. Have fun with it!
 

-- 
Paul Winkler
http://www.slinkp.com