April 02, 2021

Mics, Amp, Gain and the dreaded Feedback!

As a harmonica player, at some stage, you’re going to want to play through a mic.  You may want to be heard more clearly, change your tone or amp up for a recording session. Checkout this great explanation from our friend Will Wilde

Microphones

Put simply, a microphone is a piece of equipment that converts acoustic energy to electrical energy and amplifies the sound.  It’s the microphones ‘element’ that does this job, but for a harp player, the physical housing or ‘shell’ is almost as important.  The most  favoured housing styles are ‘Bullets’ or  ‘Stick mics’.  Bullet mics, named for their shape are popular, inexpensive mic’s from the late 1940’s.

Before you choose your mic, the question to ask is - ‘How do you want to sound?’ If you play Blues, you’re probably striving for the gritty, distorted, phat, Holy Grail sound of the 30’s. This sound is ‘amplified’ rather than acoustic and the mic is usually hand-held. There is an interaction here between the player, the harmonica, the amp and the mic. 

So, where does the gritty, phat sound come from?

When you play two notes, a 3rd note, a ‘difference tone’ is produced that is far lower in pitch.  You generally don’t hear this without amplification, but with a good amp and mic, you do.  A combination of mic and amp tend to add distortion in the form of harmonics.

Cupping.

Harmonica players have some control over  the degree to which distortion occurs through technique and choice of mic.   Microphones can be overdriven through sheer volume or by the technique of ‘cupping’. This sends a distorted signal to the amp which responds by amplifying it even further.

Cupping is an art, a learned skill.  You need good technique. Done properly, no air can escape the ‘seal’ created as you blow and draw. When the seal with a mic is good, the result is a heavily distorted signal. Bullet mic’s lend themselves to cupping and deliver the desired, big, phat tone.

Feedback.

 

This is the  ear-splitting, humming, whistling, screeching sound a system makes when a mic picks up sound from an amplifier’s speaker and returns it for increased amplification.  All systems have a feedback limit.  If you turn the volume up loud enough, feedback will occur. The prime cause  is asking for more volume than the system can produce.

Harp players often need volume close to the feedback threshold in order to be heard.

A well-designed mic can actually help with the problem of feedback, BUT  only when it’s in a stand, in free air, not in the players hand. Picking up a mic and cupping it means feedback will be an issue because the mic is constantly moving and changing direction.

Gain.

Gain is not the same as volume.  It’s the most important variable controlling an amps tendency to feedback. Amps used by harp players are  usually initially guitar amps with more Gain than a harp player needs.This can be a nightmare! Gain is difficult to adjust in most solid state amplifiers, anti-feedback pedals are needed. You have the Mojo Pad from Lone Wolf, the Squeal Killer or the Kinder Anti-Feedback.

Today we add the Kinubi PSV Harmonica effects Pedal to this list.  The PSV helps to eliminate feedback with it’s built-in Gain and Ground Lift. It can also be powered by a battery pack which further reduces hum. For more features of the PSV and how one simple piece of kit can overcome some traditional obstacles and enhance your sound.

 

For further information go to www.kinubiaudio.com

 

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