Last weekend, I was having a conversation with Dee from The Black Smoke Gypsy Band. We were setting up for their show at Fats, and the discussion came around to a question that the band was kicking back and forth:

“Should we go direct with the guitars, or is a mic’ed amp THE way to go?”

Now, I ended up giving Dee a ton of information – information that I will be soon passing along to you folks. However, Dee’s question ended up getting me to look differently at the issue of how electric guitar sounds get into a PA system. The reason that my perspective changed is that I wanted to be able to generalize the answers – that is, I wanted to be able to give advice that could be applied conceptually, instead of just as a procedure.

To be able to talk about something conceptually, you have to understand “why.” What can sometimes catch you off guard is how deep the “why” goes. When it comes to choosing a technique for reinforcing electric guitar, the “why” ends up extending all the way down into the basic principles of how any instrument creates its own signature sonics.

Why Does Anything Sound Like It Does?

If you’re going to make a decision about how to put an instrument into a PA system, you will make much more informed choices if you have a handle on what makes that instrument actually produce sonic information. The critical question in this part of the puzzle is “What are the components of the whole instrument that makes it recognizable as itself, in an auditory sense?”

Okay, that was very “sciencey,” but maybe not very helpful all by itself. Let me explain a bit.

With acoustical instruments, the whole question of how to get the thing into the PA is pretty easy, right? You mic the thingamabob wherever the best sound is coming out.

I mean, you don’t put a vocalist into a sound reinforcement rig by plugging a cable into their chest cavity. You don’t stick a mic next to their shin. The sound comes out of their mouth. That’s where the mic goes. We rarely ask ourselves “why,” because (especially with vocalists) we don’t have a lot of workable variations in mic placement. For other instruments, you can get a bit more creative. Again, though, we still end up sticking a mic in the general vicinity of where the instrument’s sound is going into the room. There’s a TON that has to do with why the sound coming out of the instrument actually sounds like that instrument, but it often gets reduced to being a question of where the noise actually gets emitted.

…but think about it:

Why can’t we run vocals direct from the vocal cords, even if we could install a pickup there? That’s what actually makes the vibration that becomes singing, right?

Yes, but there are a lot of other components in the vocal “signal chain” that  are critical to the vocal being recognizable as a vocal, and that particular vocalist being recognizable as themselves.

The vocal cords create a vibration at a certain fundamental frequency, along with harmonics and other overtones, but that’s not enough. The singer’s chest cavity and head provide important overall resonances, and a skilled vocalist can utilize and shape those basic resonances at will. The singer’s airway, tongue, hard palate, and lips produce lots of dynamic resonance shifts on the fly. The tongue, lips, and teeth are also essential to final frequency shifts and subtle (or not so subtle) sound pressure dynamics. You can’t change or delete any part of that acoustical signal chain without greatly affecting the final sound of the vocalist.

Seriously, folks. Freddie Mercury of Queen had plenty of money to have his teeth fixed. He never did, because he was concerned about lousing up his vocal sound.

You can absolutely use this same model when you think about an electric guitar.

Why Do Electric Guitars Sound Like They Do?

An electric guitar signal chain is a lot like a vocal acoustics chain.

Really!

The comparison isn’t 1:1, especially because various parts are duplicated, or occur in a different order than what you find in a human voice. Still, there is striking “sameness” to be had. Check it out:

• The guitar strings are like vocal cords. They create the basic vibration that makes the whole thing work.
• The guitar’s body resonances are a lot like the chest and head resonances for a vocal. The creation of the core elements of the guitar’s tone happens here.
• The guitarist’s pick choice, picking technique, and fretting technique are like the throat, mouth, tongue and teeth. The fundamental articulation in the guitar’s tone happens here.
• Processing that happens between the guitar and the amp has all kinds of functions. Overdrive and distortion add resonances and harmonics like a singer’s chest, head, mouth, and vocal cord stress. EQ is very much the same as a singer changing the tension and breath flow in their head, chest, neck, mouth, and nose. Heck, a wah-wah pedal is just a resonant filter with an adjustable center-frequency, which is pretty much what a mouth is for.
• The guitar amplifier itself is like another head, chest, throat, and mouth. The preamp section might be adding harmonics and resonances. The tone stack further alters frequency balance. The power amp section can add even more harmonics and resonances.
• Then you’ve got loudspeaker, which functions like another vocal cord. (More resonances! More harmonics!) That vocal cord is mounted inside an enclosure, which acts like another chest cavity, head, and mouth.

It’s pretty wild when you translate all the parts of an electric guitar setup into their vocal equivalents. If taken as a unit, the result is a wild sort of space creature with bodies inside of other bodies. Fractal geometries. Alien architecture. Somebody, call H.P. Lovecraft!

Anyway.

The sum total of all the interaction of all this stuff is a distinctive guitar tone. To paraphrase the recording engineer called “Slipperman,” every component in the system is dependent upon every OTHER component of the system. Change or omit something, and it’s not the same guitar tone anymore.

By the way, Slipperman wrote some incredible (and incredibly) educational material on an Internet forum. The knowledge from that thread, entitled “Slipperman’s Recording Distorted Guitars Thread From Hell” is available, for free, at this link.

Still, for different players and different guitar rigs, certain parts of the setup may be more or less essential to their fundamental sound. When you can determine the bits that are really critical to making the noise that the guitar player is after, you can then determine your options for reinforcing that sound.

We’ll get into the specifics of THAT in another article. (Sequel hook!)

Tweet