Earthworks is well known for producing high-quality microphones for a diverse range of applications. I had the opportunity to audition a matched pair of microphones from its SR (Sound Reinforcement) range; the Earthworks SR40 ($1,295) pre-polarized cardioid microphone.
It is packaged in the familiar Earthworks pencil-style body, nine inches (229mm) in length with a 0.86- inch diameter, and weighing 0.5 lbs. The “40” in the name relates to the frequency response that is said to be from 30 Hz to 40 kHz +/-1.5 dB. The accompanying custom calibration documentation with the Earthworks SR40 showed a virtually flat line response, with the measurements taken with the microphone at a distance of six inches from source that could handle a maximum 145 dB SPL. The polar pattern of the Earthworks SR40 illustrates a microphone with a wide front coverage, suggesting good off-axis pickup with substantial rear rejection. There is also an impulse response illustration that shows a very fast (sub 200 uS) diaphragm recovery/settling time. This is principally to do with the fact that the Earthworks SR40 has a tiny 9mm diaphragm.
I first did a few general tests with the Earthworks SR40 to get an idea of how the polar pattern and general pickup seemed in relation to the stated information. The off-axis sound is every bit as clear as the direct signal. You have to deviate considerably before any noticeable drop-off in the signal clarity. As you approach the rear, the level of rejection is very good indeed overall, but you do notice an increase in rear pickup with sources containing a larger amount of high-frequency content.
As the measured specification figures of the Earthworks SR40 related to a 6-inch distance, I was interested to see if the microphone characteristics changed when the distance was varied significantly. Generally, at distances of six inches and beyond, the response is very natural without any artificial modifications to the harmonic content of your source. The proximity effect only really starts to come into play as you move in towards the source inside six inches, and this is certainly not excessively pronounced.
Using the SR40 on drums, first as overheads, I appreciated the fabulous highend detail and clarity. Natural and crisp cymbals are helped by the lack of lower frequency pick up. The SR40 delivers a real representation from the overhead position where, so often, large-diaphragm microphone choices introduce tom (and other lower content) spill. Stringed acoustic instruments and percussion with the SR40 delivered equally pleasing results and, with the matched stereo pair, spacious and wide imaging was easily achieved. This is a microphone addition that any live or studio system would be happy to enjoy.