he e 906 features a switchable presence filter which allows you to tailor the sound characteristics to different sound requirements and styles. The filter is adjusted via a slide switch on the microphone. The slide switch is tamper-resistant - to change positions, just use a pointed tool such as a small screwdriver. The switch has three positions: one boosts the presence range (with a mid frequency of 4.2kHz) for aggressive metal rhythm guitars. The Normal position is great for classic rock. And the third position attenuates the presence range, with a mid frequency of 4kHz, for warm and smooth jazz and blues sounds.