Welcome back everyone, and thanks for sticking with me during this long series on pickups. There were so many important details to pass on that I just couldn’t fit it all in one – or even two – posts!
We are going to wrap things up by discussing a phenomenon called “feedback”. While most players hate even the idea of it (and go to great lengths to avoid it), there is that group of players that kind of dig it – and use it to their advantage as an artistic statement. Regarding the latter, does the name “Jimi Hendrix” ring a bell??
Let’s take a look at what feedback is, how it is created (using your pickups), and what can be done to minimize and eliminate it (or, for those rogue rock stars out there, how to exploit it!)
Pick Up and Feed The Beast
Have you ever wondered what that odd sound is at the beginning of “I Feel Fine” by the Beatles? Or the intro to “Foxy Lady” by Hendrix? That, my friends, is the sound of feedback.
What exactly is feedback, though, and how is it generated?
Feedback is basically a fancy name for a loop of sound energy that starts at the speaker in your amp. That sound is picked up by the pickup (that was a mouthful) and then “fed back” through the guitar. That signal is then again sent through your amp. And then back through your pickups again. And then through the amp…and so on, and so on. The resulting sound is hideous to some and rapturous to others.
Important Public Service Announcement: The same effect can be had through PA system equipment (such as a vocal microphone feeding back through the stage monitors or the main speakers), but in this case, it most certainly is NOT something that is desired – overall, feedback through a sound system is a huge no-no. Through a guitar though? Different story.
Maximize Your Control
Unwanted feedback is one thing, but if you plan on occasionally using it as a tool then you need to know how to make it happen. Crank up your amp and stand in front of it with your guitar; it’s pretty much guaranteed that you’ll get that trademark (and potentially ear-splitting) howl.
While feedback can be unpredictable, it can be used to great effect artistically when you are holding a chord or a high note at the end of a solo then stick your pickups right in front of your amp speaker. By quickly experimenting with the relative location of the guitar to the amp you can get feedback that is what I’ll call “harmonically correct”. By that, I mean that the tones generated sound great in context with the note or chord you are trying to add expression to. You can generate overtones that just sound incredible!
Minimize The Electric Effects
As far as playing with an electric guitar is concerned it’s pretty easy to minimize too. If you are in a playing environment where you are getting unwanted feedback then take everything that I said to create it and put it in reverse.
Turn your amp volume down to a reasonable level, if at all possible. In cases where you are using a microphone to get your guitar through the PA, you shouldn’t need a large amount of stage volume (which can make things hard on your sound guy and also annoy people sitting close to the stage anyway).
Amp and monitor placement is a big factor too. Have your amp behind you (hence the term “backline”), and putting it directly on the floor instead of a stand can make a big difference too. Take your monitor (normally pointing right at you) and set it off to an angle so the sound waves aren’t hitting your guitar’s pickups head-on.
Acoustics Are a Different Story
All of this is just fine and dandy, but what if you are an acoustic player? You certainly won’t get any sort of feedback from just sitting around and playing in your bedroom or studio, but it can be an absolute nightmare when trying to amplify your acoustic signal when playing live. I’m here to tell you that I have never heard of a situation where acoustic guitar feedback is considered a good thing.
There are many ways to minimize or eliminate (best choice) acoustic feedback:
Position Yourself For Success
As with an electric guitar, the easiest way is to simply move and reposition something, whether it be your guitar itself, the monitor, or the acoustic amp (not necessarily as common as many people run acoustic guitars direct into the mixing board). The inside of an acoustic guitar is a huge cavity, and having a stage monitor pointing right at it is just asking for trouble.
Bust It Up
There is an accessory that you can get at just about any guitar store – the feedback buster. This is a simple piece of rubber that presses into the sound hole of the acoustic. It doesn’t affect the tone but it helps to keep the waves out of the body cavity and also keeps the soundboard from vibrating too much due to the unwanted frequencies. If you’ve ever been on stage with a seriously squealing acoustic you’ll know exactly what I mean as the soundboard just seems to go crazy.
Some manufacturers have even integrated a feedback buster into their soundhole pickup designs – install the buster and the pickup just goes in with it…just remember that a magnetic pickup may not sound the way you really want it to.
EQ Your Way Out
If your acoustic is fortunate enough to have tone controls mounted on board then you can make quick minor adjustments on the fly to minimize the frequencies that are causing the problem. Some advanced preamps have “notching” functions that allow you to target specific frequencies without dramatically affecting your overall tone. At worst case, the EQ can be adjusted on the mixing board to help out.
To wrap it all up, feedback can be viewed as an expressive tool or a bane to your existence. Taking the right steps to either minimize or maximize it will put you in better control.
Wow – that was a long post series! I’m hoping that you came out of it with a much better understanding of what a pickup is, what it can do, and how you can use different aspects about them to your advantage.
We will be moving on to a different topic next week, so (as always),
stay tuned…
…And Peace Out!
