homepage/papers/dj.md

Title: Dirtbags DJ Setup

I DJ sound for [Dirtbags Capture The Flag](http://dirtbags.net/ctf/),
Roller Derby bouts for the [Los Alamos Derby
Dames](http://www.laderbydames.com/), and occasional parties.  All of
these have pretty similar requirements: music from a PC, maybe some DJ
mixing, and at least one microphone for announcing.  Derby is slightly
different because spaces can be larger.


My Recommendation
-----------------

This would cost about $650 in October 2011.

If I had it to do all over, and was unable to find a deeply-discounted
package deal again, here's what I'd buy:

* 2× Harbinger APS15 -- 15" powered speakers
* 2× speaker stands
* 1× Alesis MultiMix 4 USB -- USB + 4-channel audio mixer
* 1× Nady DKW-DUO -- wireless cardioid microphone pair
* Cables:
  * 2× 30' ¼ balanced -- mixer to speakers
  * 1× 6' ¼" unbalanced -- mic base to mixer
  * 1× 3' ⅛" stereo to ¼" unbalanced -- laptop/MP3 player to mixer

This will give you a nice clean USB audio out from your laptop, with two mic inputs and
a spare (analog) stereo in for an MP3 player like an iPod or Android
device: you wouldn't even need anyone to stand by the rig if you're
okay with a straight up playlist.  This mixer will also allow you to do some
basic digital recording, if you want (I do).  It's rumored to have
noise problems with the headphone out: my guess is ground loop
problems in some people's setups.  Use a laptop with a two-pronged AC
adapter and you should be fine.  In any case, if you use Mixxx, you're
not going to want to use the mixer's headphone out anyway.

You don't get any digital effects in the mixer with this setup.  I'm not
convinced you really need them.

If you want do to some live DJ control, you can use the laptop's
built-in headphone jack and a USB mouse for about $40 (I think the
Sennheiser HD202 headphones are an excellent value). You could add
something like a Hercules DJ Control MP3 e2 if you'd rather have
hardware than a mouse. The Hercules RMX looks nice, with more buttons,
a metal body, and a mic in, but at about $250 I can't recommend it
over $160 for both the MP3 e2 *and* the more-versatile 4-channel USB
mixer.


What I actually have
--------------------

This cost about $600 in July 2011.

When I bought my setup, Musician's Friend had a package deal of
speakers, stands, mics, mixer, and cables, at $40 less than the two
speakers alone.  So I bought it.  

* 2× Harbinger APS15 -- 15" powered speakers
* 2× Speaker Stands
* 1× Soundcraft Notepad 124FX -- 12-channel mixer with effects
* 2× Audio-Technica M4000S -- Wired cardiod microphone
* 1× Nady DKW-DUO -- Wireless cardiod microphone pair
* 1× SYBA SD-CM-UAUD -- El Cheapo USB Audio adapter
* 1× Sennheiser HD202 -- headphones
* Cables etc.:
  * 2× 30' XLR -- mics to mixer
  * 1× 3' ¼" unbalanced -- wireless mic base to mixer
  * 2× 6' ⅛" stereo to unbalanced ¼" -- laptop/MP3 player to mixer
  * 2× 30' ¼" balanced -- mixer to speakers
  * 1× Laptop backpack from college
  * 1× Roll of gaffer tape


APS15 Review
------------

The reviews I read on the APS15 speakers were mixed, with half saying
"they're just fine" and the other half complaining about hum, uneven
frequency response, etc.  I'm in the "just fine" camp, and will go on
the record stating that for a beginning club DJ, which is what I do
with Derby and CTF, the TH-15A is not twice as good as the APS15, despite
costing twice as much.

The speakers do hum, but it doesn't get louder as I increase volume,
and I can't hear it once I start playing music.  They're a little
muddy, and the EQ doesn't do much.  They don't stack, even though they
look like they were designed to.  Carrying them is difficult, with
only one handle on the side.

On the plus side, each speaker has two ¼" inputs (probably
unbalanced), three XLR inputs, stereo RCA inputs (presumably to hook
up an MP3 or CD player directly), and a moderately effective 5-channel
graphic equalizer.  This versatility makes it easy to use these
speakers without a mixer: something, it turns out, I want to do from
time to time for practices, parades, etc.

These speakers can't be beat for the DJ on a budget.


Soundcraft Notepad 124FX Review
-------------------------------

I'm very happy with this mixer.

This 12-channel (4 mono, 4 stereo) Mixer is nice and compact, smaller
than the 8-channel Mackie ProFX8 I use at work.  It does *not* have
USB audio, but it's very quiet and I can't see this making any
difference for CTFs, clubs, or Derby's big echo-y gymnasiums.  It has
more effects than the Mackie: I plan to use number 31 (delay) for the
announcer's mic.

I've used this mixer to bring in two DJs, two mics, my 2-channel
wireless mic system, and an MP3 player, and I still had ports left to
bring in another mic/guitar and another MP3 player *and* a recording
device, as well as an unused recording output and monitor outs.

Behringer is now making a "Xenyx 1202" which appears to be the exact
same mixer as the Notepad series in every way but color.  I had read
that Behringer's business model is based on copying the successful
designs of other manufacturers, and this appears to be the case.
Having never used a Behringer mixer and having owned many "clone PCs"
in the 1980s and 1990s, I don't feel qualified to comment on the Xenyx
series.


Nady DKW-DUO Review
-------------------

They work okay as long as you stay within about 20 feet of the base.
And they sure are cheap.
I've since bought better wireless mics,
and I prefer to use wired ones if possible.
There's just less that can go wrong with a wired mic.


DJ Controller
-------------

I don't currently use a DJ controller, although I understand the
appeal for practicality and showmanship.  I'm experimenting with a
friend's Hercules MP3 e2 and may ask for one for a holiday gift.  So
far I can say that I prefer using the mouse for setting cue points and
loading tracks.  I'm hardly ever using the platters, which seems like
the main point in having one.



Other equipment
---------------

For $60 more I bought a Nady 2-channel wireless mic system.  Then, $14
for four 9v low self-discharge NiMH batteries for them.  They work just
fine, but the plastic body will probably crack if anybody drops one.

I'm driving the entire thing with [Mixxx](http://www.mixxx.org/) through
a $10 USB Audio device, with a ⅛-inch stereo to two ¼-inch unbalanced
cable.  This is definitely the most sneer-inducing piece of the entire
setup, but after working with analog audio equipment in the 90s I feel
confident that this device is generating much less noise than the mics.

Aside from the speakers, all this gear fits into a medium-sized book
backpack.


Software
--------

I run Arch Linux on a Samsung NC10, my only computer.  My DJ software
is Mixxx.  My system is very stripped down: aside from xdm (asleep),
X, dwm, mixxx, udev, runit, a couple of gettys, and
[xss](http://woozle.org/~neale/src/xss.html), (which sleeps until X
tells it to engage), nothing is going on.  I do not run any of the
things that come with a stock Ubuntu or Gnome2 setup, such as gvfsd,
cups, dbus, or pulseaudio.

I'm able to run Mixxx with a netbook (1024×600) theme and scrolling
waveform display.  Audio is smooth.  I suspect, but don't care enough
to verify, that a netbook with a full Gnome2 setup would struggle to
keep up.  In particular, I would look first at gvfsd and pulseaudio as
a source of latency.  Even though pulseaudio is a tremendous
improvement over esd, it's still an additional layer between mixxx and
the sound driver; and many times I have seen gvfs lose its mind and
busy loop, chewing 100% CPU.