EVERYTHING DIRECT?
By Marty McCann
I am aware of a lot of church music directors that want to
do this, and they insist that the guitar player plug direct
into the console. Some folks are real naive when it comes to
this. First of all the guitar pickup is very very high impedance
and can not be run through a snake with out a Balanced D.I.
But that is still a very small part of this issue. Those of
you that are guitar players, have you ever tried to play an
electric guitar through your stereo? The sound is short of
disgusting. When you play any chord on the guitar that is taken
direct thru the console, it is like playing through that stereo.
The fundamentals are so intense that they step on or mask the
harmonics. Leo Fender recognized this many many years ago,
and that is why his amplifiers have a mid-range notch at about
250 Hz (near Middle "C"). Most other conventional guitar amplifiers
have a similar notch, sometime a little higher in frequency,
but never the less they are notching out the mid's.
There are no "Flat" settings on most guitar amplifiers. Most
of them have passive tone controls (Not all but most). Passive
tone controls are "Cut Only," and by their nature interact
considerably. What do I mean by that, well if all of the tone
controls are not at "10," if you turn up the Bass control,
you get more bass as you would expect, but most players don't
realize that the treble sound has just diminished as well.
If you turn down the treble, the bass will also increase. The
mid-range notch and the interacting passive tone controls are
only a part of the mechanism of electric amplified guitar.
You also have the sound of the tubes (in a vacuum tube amplifier),
which have their characteristics. And when the guitar is played
at high power levels for any particular tube type amplifier,
the saturation of the output transformer contributes quite
a bit to that rock and roll sound we have come to love.
It's not over yet; lead rock guitar players are also getting
some of "their sound" from the way in which the guitar amps'
loudspeaker breaks-up. Guitar amplifier loudspeakers are different
from sound reinforcement loudspeakers, in that in sound reinforcement,
we don't want any distortion added to the sound by the speaker.
We want a linear "Reproduction" of the sound that has been "Produced" by
the guitarist. Now a rhythm guitar player or jazz player may
prefer a speaker in their amp that doesn't break up. A lot
of musicians (and sound folks) don't understand the role that
harmonics play in music. Some think that any and all harmonics
are cool. Well, low order even harmonic distortion, indeed
can be cool, it's a bit like having another guitar player playing
the same chord an octave higher along with you.
And a small amount of odd harmonics can be found in some rock
reproduced electric guitar spectrum. But, harmonics are only
musically related or consonant within about two octaves above
the played fundamental, after that they can become dissonant
or unmusical. In the case of a jazz player, who may diminish
a ninth or augment a 13th, he has essentially added an odd
component to an otherwise consonant chord. This jazz player
would not want his amplifier to add a harmonic of this 9th
or 13th note, as it would dramatically change the perception
or jazz sound of that chord.
The cone break up of the loudspeaker that I referred to in
a previous paragraph comes in to play when the guitarist plays
his rock and roll lead. The break-up of the loudspeaker designed
for that amplifier initially adds rich harmonics to the note.
In fact, the phrase cone break-up unto its self doesn't sound
like it would be desirable, so the guitar amp loudspeaker designers
call this euphemistically, "cone cry."
I realize this kind of has become a treatise on guitar amplifiers,
but I still think it satisfies the spirit of the question about
taking instruments direct into the sound system. There are
preamps and stomp boxes today that can contribute some of the
above, and of course there are modeling amps and may very well
be modeling preamps or foot pedals, I don't know because it
has been a long time since I was responsible for M.I. amplifiers.
My recommendation is that sound people be made aware of the
above information before they let some one arbitrarily plug
that electric guitar into a D.I. It is certainly no problem
to take bass guitar, acoustic guitars, keyboards, and other
instruments directly. However if you are going to send these
signals down a long microphone snake, you need to have a balanced
connection between the source and the FOH mixer. This is where
the D.I. box comes in as it provides the balanced interface
between the instrument/amplifier and the sound systems mixer. |
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