I like bluegrass music. I don't like hours of it but I like twenty minutes of it. I especially enjoy the Isaacs. I like them because they have taken bluegrass music to where I always wanted to see it go. I also like them because they are just plain old GOOD, period. And, I like them for a third reason. I'll get around to why later. You may be asking yourself why I would include this in my article, or, maybe you couldn't care less. Either way it's there.
I am going to follow up last week's article with another that deals with similar aspects of mics. This one is going to deal with the on/off axis of the mic's characteristics. When I refer to "on axis" I am talking about being directly in front of the mic at a very direct angle. To be at either side of or even above or below the mic is considered "off axis" even a little. I mention this because as a performer moves to the left or right, above or below this direct point the mic's responses change considerably. When you are on axis to the mic diaphragm, this is the most effective direction you can be for frequency response and mic output.
As you look at the diagram it is representing an above, looking down view of a person at the mic. This is a flat plain representation, but in reality this is a spherical application which is why I stated above or below the axis.
If you have a diagram of the on axis response pattern for a specific mic you will see a circle with numbers on it very much like that of a compass rose. Beginning with zero, (0) and moving to the left or right the numbers will be represented in degrees. The numbers can start at any number and contain additional increments as they progress around either side of the diagram. Basically, regardless of direction, left, right, above or below this zero reference the response will remain consistent. Now then, as you can see by the different lines this is an idea of what the various frequencies will be on axis. The frequencies will be represented in three or possibly four different ways. Check the legend to see which line type represents a specific frequency or group of frequencies. The easiest way to get familiarized with this chart and avoid much confusion is to select one specific line and study it as the changes in direction take place. As you move to the left or right, (above or below) this line changes its signal strength in those frequencies. Signal strength is represented by the inner circles within the chart, and measured in decibels. Each line representing a frequency or group of frequencies will be drastically different in strength as the off axis position shifts in any direction.
So now, why is that important and what does it have to do with the Isaacs?
My biggest problem with the purveyors of bluegrass music is their overall lack of technical knowledge about mics, PA systems and other stuff. I say this because bluegrass musicians do not realize just how much even the slightest directional change can affect their music. This is relevant because almost every bluegrass musician considers themselves to be musical purists. Meaning nearly ALL of them usually always choose the very best in acoustic instruments without any kind of electronic transducers attached. It violates some kind of creed or something. The bluegrass pickers absolutely do NOT want pick-ups on their prized Martins, Gibsons and Nationals because it compromises the "natural sound" of the instrument. Instead they will insist on using...ready...MICS. Why? “Mics reproduce the natural acoustic quality of the original instrument.” Bull-loney! Every mic has such extreme response characteristics built into them it is absolutely impossible to defend such attitudes. Even with the exceptional quality controls in the companies themselves mics can convey discernible variations in responses. A Shure SM58 does not sound like an Electro Voice, or a Beyer dynamic or an Audio Technica or a Crown or... you get the point.
When you take this into consideration along with what happens when a performers axis changes direction, coupled with a change in distance it isn't long before that acoustic integrity rational goes flipping right out the old window (I was going to say "goes south" but didn't want anyone to think I was being disparaging. I love the South and everything represented by it and would never demean it in any form). My ultimate point is this: the moment anyone ads ANY type of electronic transducer to an acoustic instrument it becomes something else. It's inescapable!
I was watching a group of bluegrass pickers one evening and I noticed the mic had tilted downward at the resonator guitar (see, I didn't say Dobro). The person playing it never corrected the situation because I doubt they had any concept of just how much this was affecting their performance. Frequency response changes, output levels are reduced or enhanced drastically and both of these combine to create a radically different sounding instrument, good or bad, usually bad.
One thing I have always stressed when involved with sound is this: it is NOT the sound person's responsibility to compensate for a performer's laziness, apathy or ignorance about their equipment. It's as much or more so their responsibility to make sure the various aspects of equipment, placement and overall use of said equipment is done professionally. The sound person is not, or should not be, a baby sitter for lazy, indifferent, or uninformed and ill-informed musicians and singers; it's not the sound person’s job. If an individual doesn't care enough about the quality of their performance, then why should anyone else?! There was a singer who had let their mic drop down very far away from their mouth and the sound guy, (it wasn’t me) kept pushing the fader trying to keep them in the mix. Naturally they ended up with that wonderful screeching howling feedback sound so prevalent in churches. I instructed them not to try and compensate for the singer’s unprofessional laziness. It only made the sound person look incompetent and became an unnecessary intrusion and distraction. If the performer doesn't care about the sound, neither should the sound person.
About the Isaacs. I mention them because they are one of only a few bluegrass groups who WILL use add on transducers in their presentations. They use the stick-on type pick-ups on their high end top of the line instruments and always put out a stellar presentation live or recorded. In spite of this fact, even those stick-ons can have adverse affects on some frequencies but not to the point where it damages or compromises their songs. If you are going to insist on using mics only, fine, but at least try to understand the basic characteristics of those things before you start spewing misinformation, especially to the technically uninitiated. By the way, misinformation is far worse than no information.
Tip: I play bluegrass music and I do it on a bright red Fender STRAT. It sounds just as good as it does on the other instruments, maybe even better. I even add distortion sometimes. Bluegrass on a Strat ROCKS.
I personally think guitar music is the most beautiful music that can be played bar none.
I'm right, right?! Let me know what you think unless you disagree with me about this. I just don't think I can stand to be wrong about this one.