Subject: Re: [linux-audio-user] Newbie introduction
From: Paul Winkler (pw_lists_AT_slinkp.com)
Date: Fri Apr 12 2002 - 05:21:42 EEST
On Thu, Apr 11, 2002 at 03:35:11PM -0400, Lloyd R. Prentice wrote:
> My final product will be voice over the web. Ideally I'd like to deliver audio
> quality at least as good as any of the popular streaming audio sites. If it
> sounded to a web listener like NPR over FM I'd be delighted.
In that case, you can comfortably ignore the hype about 24-bit/96k
soundcards. "CD spec" (16/44.1) will do fine. Think of 24-bit as a nice
bonus if it's under budget, and think of 96k as total overkill for your
application.
I'm imagining that ulitmately I'll have one or more workstations devoted to
> recording, editing and mixing audio content. Recording might involve a few
> microphones and a telephone line feeding into a mixer. Are there sound cards that
> accept multiple analog inputs? Or would it be simpler/less costly to use an analog
> mixer that, in turn, feeds into an audio production workstation?
Given that you want "a few microphones", you'll need preamps for those
microphones, and by far the most cost-effective way to buy mic preamps is
with a mixer attached. :) So you'll have an analog mixer around anyway.
For the situation you describe of mixing a panel discussion for live
broadcast, the signal chain is very simple:
____________
mic 1 ---> | |
mic 2 ---> |analog mixer| L output --------> stereo
... | | R output --------> soundcard
mic N ---> |____________|
That's all you really need to do everything you describe.
The mixer will feed your headphones, too.
The only reason you'd want more than two channels input
is if you have e.g. three or more microphones *at once* that
you want to record and then mix or edit separately *in the computer*.
Otherwise, you're fine with an external mixer.
If you never have more than two live signals, you can pile up
dozens of tracks in the computer and still mix and edit them
in software. For example, you've recorded three speakers at a
panel discussion. In the middle of the discussion, one of the speakers
sneezes very loudly into his microphone, right in the middle of
an important point from one of the other speakers. If you mixed
all three voices to a stereo signal before it went in to the computer,
you won't be able to do anythign about it. But if you recorded
each mic to a separate "track" on the computer, you can later
find the precise spot of the sneeze and mute the offending track
at just that point (though of course it probably leaked into the
other mics a bit).
How important is it to be able to do this kind of thing?
Only you can decide that. For live broadcast, it won't matter
anyway.
Likewise, you don't need more than 2 analog outputs unless you
want to do things like
* play >2 sources from the computer and use an external mixer to mix
them
* feed different headphones mixes to different people
* use external analog (or digital) processors on material that's
already in the computer
Good values in analog mixers:
Mackie 1202 or 1402, Soundcraft Spirit Folio series.
I have both, they sound about equivalent in quality. The Spirits
are cheaper and larger, and possibly less durable.
> 6) What's your budget?
>
> I'd like to keep costs down to $500 or less while I'm climbing the learning curve.
> But will spend what's needed once I feel that I'm ready to go into production.
Is that $500 for everything? Tight, but you could get a used mixer for
$200-ish, a used M-audio Delta 44 for under $200, and a couple used
Shure mics for $50 each. Radio stations have been started with far
inferior gear. :)
But then you'll also need cables and a couple of mic stands.
Can't forget the essentials...
> Sorry to sound so vague. But I've already learned much from your questions.
> Perhaps you could recommend two cards -- one that would see me through the
> learning curve and one that would deliver solid professional sound for the long
> term.
I have and love the M-audio Delta 66. It has 4 analog ins and outs,
S/PDIF in and out, and does 24-bit recording and sounds *very* nice.
The Delta 44 is identical but without the S/PDIF, so it's a bit cheaper.
They also make a 2-channel card called the Audiophile, but
I've seen a lot of messages from people on alsa who can't seem to
get it working. I haven't paid close attention so I don't know if
that's a problem with the card, with
the driver, or with the users. :)
If you get into heavy multitracking work and need more analog
inputs or outputs, there are basically two higher levels:
the M-audio Delta 1010 which has 8 analog ins & outs plus S/PDIF,
and the RME Hammerfall series, which has more digital channels than
you can shake a stick at, but requires you to purchase separate
A/D and D/A converters. Of course now you're talking a lot more
money.
At the lower end, there are also "consumer" soundcards with stereo
inputs and outputs
that would definitely work fine for your trial phase.
I'm not really up on what's what... a year or two ago everybody liked
the Ensoniq Audio PCI, but they got bought by Creative and I
lost track of what their different cards are.
I've heard reports that the SB Live! has pretty decent analog input and output.
So you could probably make do with a $50 soundcard for now,
and it *might* prove adequate for your production system.
Streaming audio over the web is not exactly the most demanding
hi-fi application... neither is FM radio, for that matter...
> I've been reading about ALSA. I believe that the latest S.U.S.E. distribution has
> integrated it. I much appreciate your offer to help install it. I'll look into
> S.U.S.E. and study to docs, then see where I stand.
I don't know about SUSE, but I think some distributions are still
shipping alsa 0.5.x, which is ancient history. You want the current
beta series, 0.9.x. Debian Unstable offers it, I don't know about
other distributions. But it's not really that hard to compile
and install from source.
> I haven't used any of the digital audio tools, so I don't know what's possible,
> what to expect, or what can be integrated to into a productive work environment.
I think you're in for a bit of culture shock. :)
> Years ago I cut 1/4-inch tape with a razor blade and stitched it together with
> sticky tape; used analog graphic equalizers and filters and stuff.
For basic editing and processing, snd with Dave Phillips' interface
customizations is very nice for me. Read Dave's articles at
http://linux.oreillynet.com/pub/a/linux/2001/10/05/snd_partone.html
... though be advised that updates to snd have since been released
which make some of dave's mods obsolete.
You're probably going to be using very long soundfiles, so you need
an editor that can handle it. Snd will do fine there, as will
many of the more recent editors (glame I think?).
Older editors tended to want to slurp everything into RAM
(e.g. DAP, MiXViews).
> So I presume I need tools to record sound clips,
tons of these. I still tend to use ecasound on the command line.
simple and reliable. You can record directly into most editors, too.
Snd is a bit iffy in this area.
>convert across a useful variety
> of file formats,
ecasound, sox, many of the available editors can handle a lot of
formats...
> listen to clips stored in different file formats,
ditto. the "play" script that comes with sox can play just about
anything that isn't compressed. ecasound handles a lot of formats.
snd too.
> equalize
LADSPA plugins used in a wide variety of apps...
> and
> mix sound clips, archive sound clips.
For mixing, ecasound is useful but the command interface is complex.
Maybe try one of the multichannel editors such as audacity, glame,
etc. Might be just what the doctor ordered.
Ardour can theoretically do all the editing and mixing you want,
but it's still in alpha status and evolving rapidly so I don't
think you'd want to depend on it just yet.
I don't know about organizing stuff in an archive, I think you're on
your own for that. I don't have a lot of sound clips so I just stuff it
in whatever directory names I think of off the top of my head,
and do backups with tar.
--Paul Winkler home: http://www.slinkp.com "Muppet Labs, where the future is made - today!"
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