Noise Floor Comparison of various Microphone - Recorder Combinations The inherent noise floor of a recording system is determined by the noise components contributed by both the microphone preamplifier inside the recorder and the microphone (the two noise components add geometrically). It is desired that the recorder's preamplifier does not significantly degrade the overall noise floor of the recording system. If it is acceptable that the preamp degrades the overall system noise performance by up to 1.0 dB, it will be sufficient that the recorder's noise floor is at all relevant frequencies about 7 dB below the overall (microphone + preamp) noise floor. The following table indicates the combinations of microphones and recorders that meet that criterion by green + signs. Note that this kind of evaluation is only relevant for recording under optimal conditions in very quiet environments. In most practical field recording conditions however, the inherent noise floor of the recording system will be masked by the more intensive environmental noise floor.

preamplifier noise preamplifier + microphone noise 150 ohm Sennheiser Sennheiser Rode termination K6/ME66 MKH60 NT1-A 50 mV/Pa, 10 dBA 40 mV/Pa, 8 dBA 25 mV/Pa, 5 dBA

dB dB dB dB -125 -125 -125 -125 -130 -130 -130 -130 Sound Devices -135 -135 -135 -135 -140 -140 -140 -140 -145 -145 -145 -145 722 [1] -150 -150 -150 -150 -155 -155 -155 -155 -160 -160 -160 -160 -165 -165 -165 -165 EIN: -128 dBu -170 -170 -170 -170 0 5 10 15 20 kHz 0 5 10 15 20 kHz Sens.: -46 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz +++ +++ ++

dB dB dB dB -125 -125 -125 -125 -130 -130 -130 -130 TASCAM -135 -135 -135 -135 -140 -140 -140 -140 -145 -145 -145 -145 HD-P2 -150 -150 -150 -150 -155 -155 -155 -155 -160 -160 -160 -160 -165 -165 -165 -165 EIN: -125 dBu -170 -170 -170 -170 Sens.: -40 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz +++ +++

dB dB dB dB -125 -125 -125 -125 -130 -130 -130 -130 marantz -135 -135 -135 -135 -140 -140 -140 -140 -145 -145 -145 -145 PMD671 -150 -150 -150 -150 -155 -155 -155 -155 -160 -160 -160 -160 -165 -165 -165 -165 EIN: -123 dBu -170 -170 -170 -170 Sens.: -50 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz +++ ++

dB dB dB dB -125 -125 -125 -125 marantz -130 -130 -130 -130 -135 -135 -135 -135 -140 -140 -140 -140 PMD670 -145 -145 -145 -145 -150 -150 -150 -150 -155 -155 -155 -155 EIN: -118 dBu -160 -160 -160 -160 Sens.: -52 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz ++ +

dB dB dB dB -125 -125 -125 -125 marantz -130 -130 -130 -130 -135 -135 -135 -135 -140 -140 -140 -140 PMD660 -145 -145 -145 -145 -150 -150 -150 -150 -155 -155 -155 -155 EIN: -118 dBu -160 -160 -160 -160 Sens.: -52 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz ++ + -

dB dB dB dB -125 -125 -125 -125 M-AUDIO -130 -130 -130 -130 -135 -135 -135 -135 -140 -140 -140 -140 MT24/96 -145 -145 -145 -145 -150 -150 -150 -150 -155 -155 -155 -155 EIN: -113 dBu -160 -160 -160 -160 Sens.: -45 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz 0 5 10 15 20 kHz + --- [2] -

dB dB -125 -125 EDIROL -130 -130 -135 -135 -140 -140 R-09 -145 -145 -150 -150 -155 -155 EIN: -104 dBu -160 -160 Sens.: -41 dBu 0 5 10 15 20 kHz 0 5 10 15 20 kHz -

Conditions: Sample rate: 44.1 kHz, Bit-depth: 16 bit, Max gain, AGC: off, Noise reduction: off, Dither: off, FFT size: 65536 (RECT window) [1] The harmonic noise artifacts on the SD722 recorder are caused by a failure of the individual test unit and should not appear on other series units. [2] The very high noise level is caused by the non-standard phantom power voltage of 30V that is incompatible to the MKH60 microphone. © Raimund Specht, Avisoft Bioacoustics, www.avisoft.com