Supercardioid dynamic microphone
The Sennheiser e906 is an affordable, supercardioid dynamic microphone tracing its ancestry back to the legendary, and now pricey, MD409. This compact, almost laughably shaped, microphone is deceptive--much like its forebearers and spin-offs there's a lot of sonic potential waiting to be unleashed.
Feature-wise the e906 has a three position switch to affect presence, which can be boosted, cut or left neutral. The e906 handles transients and SPL without difficulty. Thanks to its odd design and small footprint you can place these in cramped positions--ideal for tom mics. The ultra-tight pattern is good for eliminating bleed, but in my opinion its so tight that micro-placement is an issue. Make sure to LISTEN when you place these (which you should be doing anyways) because relatively minor adjustments can make a big impact on the final product. Other than that, the Sennheiser is a breeze to use.
In practice these are good microphones well suited to percussion, guitar cabs and the like. Probably not a good choice for vocals, not as much for the sound, but the look of horror on the singer's face when you put this "frying pan" in front of them. The supercardioid pattern isn't very forgiving if your vocalist likes to dance around. Overall the response is a bit throaty, with a touch of grain and the potential for brightness; when misapplied the e906 can display some stridency or shrillness. This mic doesn't shine everywhere, but on the correct sources it becomes quickly obvious that you've got a winner. Make sure to play with the presence controls before making a final decision, as each of the three settings are very different from one another. It's almost like having three mics in one!
While e906's and the like are often put in front of guitar amps, where they are well suited, my personal opinion is that their best application is on tom microphones. Due to their narrow pattern, good off-axis rejection, crispy and "tough" sound they excel in this capacity--especially with the presence boost switched to "on." Not to mention their minimal footprint and the ability to get them very, very close to the drums, yet out of the way of errant drummer hits, make them ideal. The e906 is useful both on top AND bottom of toms, and provide a cost-effective way to double mic toms (which in a project studio is a total luxury). Another place these mics are awesome is the bottom snare, where their rejection, brightness, size and tone are well-suited! Heck, they almost make the under snare sound good! For more ethnic percussion, like congas, bongos and the like they really shine.... set them up in stereo arrays with a mono LDC as a room mic and enjoy!
Bottom Line: these mics often get a bad reputation because they really aren't as good as its predecessor, the MD409. Not all is lost, because these are still quality microphones with a number of new features. Not to mention the difference in quality is pretty forgivable for most applications, possibly guitar withstanding. Watch out of the upper mids, because they can get excessive on the wrong source. Every well equipped studio should have 4-5 of these (or its derivatives/relatives) in their mic locker. They just get you out of jail free too often to be ignored.