Flanger

Basics of a Flanger Pedal

Flanger pedals were first introduced the music world back in the 1960's. This phenomenon was discovered when sound engineers would delay one of the reel to reel tape recording machines ever so slightly. This was achieved by lightly pressing the flange of the reel and causing the slight delay. As the engineer couldn't apply a perfectly consistent amount of finger pressure, the delay time between the primary reel and the "flanged" reel varied......this variance (or modulation) created the flanging effect. The flanging sound, for lack of a more technical term, is similar to an airplane taking off and landing. From a recording standpoint, the flange effect was very dramatic and not practical for an entire song. Thus, the sound engineer would slightly delay (touching the reel flange) the primary reel appropriately to match the delayed reel and the bring the two reels back into "phase" together. By in phase, we mean that the wave forms of the two identical signals are directly on top of each other.....no delay whatsoever. When two signals are in phase, there is no sound cancellation or reinforcement. A slight delay creates the aforementioned cancellations and reinforcements, also commonly referred to as notches. These notches, when graphed, resemble a comb....i.e. comb filter.

Flangers pedals, generally, have shorter delay times when compared to chorus pedals. Thus, you can actually take a chorus pedal, decrease the delay time and somewhat approximate a flanger pedal. However, the amount of internal feedback (or resonance) on a flanger pedal is very important. This function (button) on the pedal allows the reinforced frequencies to be emphasized internally within the pedal (i.e. feedback), making the "airplane" effect much more dramatic. Like a chorus pedal, most flangers have delay, sweep/width/depth, and speed/rate functions. The delay function (button) sets the minimum amount of delay. In the case of a flanger pedal, we're talking 1 to 10 ms. The sweep/depth/width button controls the amount of change/modulation (over a certain amount of time) for the phase (timing), frequency (pitch), and amplitude (volume) of the signal. The higher the setting, the more noticeable the effect is. The speed/rate button works in conjunction with the sweep/depth/width button. If the speed/rate button is increased, the sweep/depth/width button will go through it's changes (modulation) faster. This is especially noticeable with a flanger pedal, where you can hear how often the airplane takeoff/landing sound regenerates. This is also sometimes referred to as the "cycling" time. Additionally, you may see a "level" or "mix" knob on a flanger pedal. This generally adjusts the volume of the processed (cloned) signal in relation to the original signal.

A flanger pedal differs from a phaser pedal primarily because all of it's frequencies are equally delayed (sometimes referred to as being musically related) when compared to the original signal, even when the delay time is changing (modulating). In a phaser pedal, not every frequency has the same amount of delay time when compared to the original signal due to the use of low pass filters.