I own a Soundfield ST450 MKI (and the more expensive DSF-1). The ST450 MKII is quieter and has better phase accuracy than the MKI.
Yes you can get a good stereo recording of a singer with a guitar. In a good acoustic space
I would try putting the mic a few feet in front and
above and decode to omni until you find the right
direct to reverberant balance and then try Blumlein decode. (The plane of the Blumlein should be tilted down to achieve the best balance of
vocal and instrument). If the singer bends their
neck down to look at the strings while playing
then you may need to position the mic lower.
As others have said there are lots of other good
mic options. I would definitely consider future uses and not just this project in your decision making.
Reasons to consider purchasing the
Josephson or Soundfield:
1.flexibility of Ambisonic decoding in post
(ST450-horizontal and vertical, Josephson-
horizontal only)
2. ST450:smaller mic size, portability (battery operation) and dedicated preamp/processor (quite compact) only need recorder with
4 gain-matched line inputs for B-format or 2 if you want to record a stereo/MS decode ( 4+2 if you want to record both). Controls on the preamp/processor allow for continuously variable adjustment of the mic pattern and stereo width for the stereo/MS decode. (Control over rotation and vertical tilt is only available in software).
The preamp/processor plus battery plus separate recorder can easily fit in a bag for walking around.
Works fine outdoors (with Rycote blimp). (Has internal mic heating element so you can use outdoors even in a humid environment without problems like other AF
condensers). Also good choice if you want to do VR work. Uses special mic cable (with 12 pin Lemo connectors) to connect mic to preamp/ processor.
The preamp/processor line outs are on 3 stereo
5-pin XLRβs (βWXβ, βYZβ and stereo/MS).
3. Josephson-havenβt used it but I have C617 omniβs so I know their quality.
Larger in size compared to the ST450 so a consideration if visuals are an issue. Not portable. Need to provide separate clean
3 channels ( 1 for each capsule) of preamp.
To get a stereo decode you need a 5 channels on a mixer, see
http://www.josephson.com/pdf/srs7.pdf,
or more simply, a B-Format decoding plug-in like the free Soundfield Surroundzone2.
Thanks,
Bill