A comparison of the CoreSound Tetramic (CS 2050) and a pre-series prototype of the Soundfield ST450. Jörn Nettingsmeier January 2011 Thanks to Soundfield Ltd. and S.E.A. Vertrieb & Consulting GmbH for providing me with an ST450 for testing. The Tetramic was recorded in A-Format and processed with Fons Adriaensen's Tetraproc using the custom filter coefficients provided by CoreSound. The ST450 went through its preamp/converter box, which produces B-Format. Both mics were co-incident, the ST450 mounted upright in its cradle, and the Tetramic on top, in end-fire mode. They were recorded through an RME Micstasy with digitally controlled and matched gain, via ADAT through a Focusrite Saffire PRO26, to a Linux Audio workstation running Ardour. The tracks have been roughly matched for equal loudness and rotated for congruent localisation by ear. All files are classical first-order B-format 24bit WAV at 48khz. If you want to listen to them on stereo speakers, you can either use a UHJ encoder, or a virtual stereo microphone. Both are available as LADSPA plugins for Linux and Mac users as part of Fons' AMB plugin package. For users of that other operating system, Google is your friend. For serious A/B comparison, you should probably import each pair of files into some DAW and play it back in sync while switching between the mics. For recreational listening under Linux, try starting JACK and AmbDec with a suitable first-order decoder, and then use mplayer -channels 4 -ao jack:port=ambdec . *.* First, two brief excerpts from a concert by "The Kites", a recorder ensemble from Germany. The concert was part of the Montag-Tontag series at the Kunsthaus Essen, a very small location that holds about 40 guests if you squeeze them a bit. Way too close-miked for recorders, directly in front of the stage, about 1.5m away from the musicians, at standing ear-height. And of course the acoustics are quite hostile to recorders, so Fons' zita-rev1 had to help a bit. Still too direct for my taste, but good for comparing mic performance. Ye olde Englishe musicke, with some very neat ad-libbing over "Pastime with Good Company": The_Kites-Three_Pieces_from_the_Court_of_Henry_VIII-CoreSound_TetraMic-24bit-48k.amb The_Kites-Three_Pieces_from_the_Court_of_Henry_VIII-Soundfield_ST450-24bit-48k.amb Dave Holland's "Conference of the Birds". The Petzold bass flute was gently amplified using an AER acousticube amp on stage. Something apparently bumped into the mic stand during the performance, thus a GLAME 5-pole highpass at 100Hz was applied to both mics. Same reverb settings as before. The_Kites-Conference_of_the_Birds-CoreSound_TetraMic-24bit-48k.amb The_Kites-Conference_of_the_Birds-Soundfield_ST450-24bit-48k.amb You will notice that the applause is louder on the rear left - that's how the audience was seated. *.* Next, a 12-minute free improvisation by Vincent Royer on viola, Stefan Werni on double bass and Thorsten Töpp on classical guitar. Same location, roughly the same microphone position. No amplifiers - yes, that _is_ a weapons-grade double bass. Beautiful collaboration with a keen sense for space and tone - give it a spin even if the word "free jazz" gives you the creeps, chances are you'll like it. In any case, it's a great test signal. No artificial reverb this time, the Kunsthaus works quite well for this kind of intimate music. Royer-Werni-Töpp_Improvisation_#3-CoreSound_TetraMic-24bit-48k.amb Royer-Werni-Töpp_Improvisation_#3-Soundfield_ST450-24bit-48k.amb You should hear the viola to the right, the double bass in the center, and the guitar to the left. *.* My private conclusion: The ST450 is quite bassy and warm, which can be nice but it's not how I like my microphones. However, it's easily tuned to taste with some gentle EQ, and I can see how the basic sound would appeal to most musicians and location recordists. The Tetramic does an amazing job for the price, if and only if the music is loud enough. I have no clear preference for the sound of either, although the ST450 is nicer to tricky instruments such as strings, or voices. But if you need better signal-to-noise ratio, there's no way around the ST450. Of all the Soundfields I have used so far (a DSF-1, a Mark IV, an ST350), the ST450 has the best localisation. Unfortunately, it will set you back by about 4k pounds, which makes the Tetramic look really good in comparison. But that price includes a very good beltpack-sized matched preamp with stereo monitoring and B-format line outs, and a very roadworthy, professional package with a sturdy balanced multicore and LEMO connectors (as opposed to the flimsy nightmare that is the Tetramic's cabling). If you want it quiet and precise, there's no match for the ST450. As soon as I have the cash, I'll get one. But it may well be the Tetramic that earns it :)