3111 Elements of good portable sound
Date: Wed, 12 Jan 2005 11:07:51 -0800
From: Michael Knowles <binkster@BINKSTER.NET>
Subject: Elements of good portable sound
I applaud the modern DJ that can mix songs flexibly and intelligently
into tandas on the laptop in response to crowd participation. This is a
nice step up from tandas burned onto CDs and tapes where the tandas seem
to be 'set in stone' and in practice are rarely reordered or tweaked on
the fly. I like to have pleasant surprises while I'm dancing a tanda.
I agree with David Liu that very high bit-rate uncompressed songs are
the ideal format for the laptop DJ. Modern computers have plenty of
storage space for such large files. Using an external USB sound device
can help, too, in that the sound will have greater depth -- there will
be less computer CPU interference with the sound-making circuits -- less
clock-noise, less hiss, fewer strange whining or clicking sounds etc.
(You would be amazed at how much the video activity of a laptop is
converted to tiny clicky noises at the headphone jack.) I disagree with
David that choices of wiring will have as great an effect on the sound.
During double-blind tests in which I've taken part 'expensive' wire
never wins against an appropriately-sized workaday wire. Wiring
resistance/capacitance/inductance vs. frequency response is a very
complicated subject filled with quite a lot of market-speak which would
certainly bore the greater number of tango-list readers since the actual
benefits of 'audiophile' wiring are more often observed in the MHz
(radio) range, not the audio range. The thing for the tango DJ to
remember is that nearly every other thing you can do to improve your
sound system will have a greater impact than will the selection of one
or another kind of wire. Speaker selection is by far the most important
element for revealing recorded sound quality, being equal to microphone
selection for the sound of a live band.
Comparing the available USB sound devices means plowing through a bunch
of ads and confusing literature. You can optimize for very high quality
or very low price. Though you can select an esoteric model and fight
with its drivers to make it work with your operating system and DJ
application I think it's easier to aim down the middle and pick one of
the major players who have worked out most of the incompatibility
issues. Creative Labs' Extigy is a fine USB audio device which offers
better sound quality than the great majority of laptop headphone jacks.
I work with customer-supplied MP3 files all the time in my career as a
live sound engineer. They are undeniably handy in that they have a small
size. Certainly, you can use mp3s for your big milonga and it's possible
your audience will enjoy themselves without getting a sense of lost
depth. For me, though, flipping back and forth between the full-range
source and a low-bit-rate mp3 made of that source clearly shows the
amount of detail lost, so why bother going through the mp3 process at
all? Simply use the original file!!
Please, if you are married to mp3 files for tango DJing, can you begin
to move your collection up to the highest bit rate your gear can handle?
256-320 kbit/s is the range I use for my own work-related mp3s. Yes, I
use the Lame encoder, though I don't feel the need for VBR since I like
a full stream of info even with simple sounds. Note: if the original
recording is mono, it's possible to get better sound quality if your mp3
is also mono. The same bit rate applied to only one channel of audio
gives double the effective bit rate. Or you could settle for the same
sound quality but with half the file size. Not every mp3 ripper will
give you the mono option -- Xing's AudioCatalyst is one of the few that
does. The range of 128-160 kbit/s is good enough for mono tango files.
As far as getting the laptop sound to fill the whole dance hall, this is
not the time for a set of $100 computer speakers, nor is the task going
to be completely answered by any portable boom box that has an external
input for your laptop. Professional speaker systems with horn-loaded
high frequency drivers raised above head height will do the trick much
better. Typically, pro speakers will have a better frequency response
and the ability to carry good sound further with far less distortion. If
your situation forces you to use a boom box, try experimenting with
boundary surfaces to make the sound fill the space better. Setting your
boombox on the floor and pointing it into a corner of the room can yield
a surprising improvement in the ability to fill the room with sound,
depending on the room's architecture and boombox placement. Turning
_down_ the bass knob will allow an inadequate boom box to reproduce the
mids and highs in a way that has less distortion at high volumes. You
will regain most of the lost bass power if you position your boombox
against the floor and a wall or two. Outdoors in a plaza with no walls
is much worse: the only thing that you can do to help your boombox is to
place the boombox on the ground for added bass response. Far better to
have professional speakers to cover the area.
The smallest professional portable sound systems will outperform most
boomboxes. Peavey's Escort is one example:
https://tinyurl.com/5to4b
Larger portable sound systems are legion -- there are too many to choose
from. Mackie's SRM450 speaker continues to be very popular because of
its well-behaved sound properties. Though each one is 600-700 US dollars
and weighs 51 pounds (23.2 kgs) they still fall in the portable category
-- get yourself a handcart for schlepping and an assistant for
placement. Again, any professional speakers will work best positioned
above head height. Get yourself some sturdy tripod stands such as
Ultimate's TS90B or TS99B.
I hope that helps clear up some confusion in what is a very complex field.
--
Michael 'Bink' Knowles
binkster@binkster.net
www.binkster.net
