hcdjp wrote:When you talk about M/S mics, is Sennheiser Mkh 418s P48 a good option?
The MKH418 is essentially a 416 with a built-in sideways-facing fig-8 element to provide the Sides signal. It was developed essentially to provide a stereo option for TV sound recordists who wanted to retain the familiar 416 characteristics.
It will certainly provide a stereo MS signal with a lot of mid-focus, if that's what you want.
I don't know how the cost compares, but the Rode NTG3 is effectively a reverse-engineered MKH416 at a much lower cost, and that combined with the clip-on Ambient Emesser I mentioned above might well work out to be more cost effective.
Is it better to go for one mic instead of two for a good M/S setup?
From a stereo sound point of view it makes little difference, although being able to swap out the Mid mic for others with different polar patterns can be a useful option open to a dual-mic setup but excluded from (most) single mic ones.
I use a two-mic MS setup in a Rycote Cyclone windshield:https://www.soundonsound.com/reviews/rycote-stereo-cyclone
This allows me to use omni (MKH20), cardioid (MKH40), or supercardioid (MKH50) mid mics, along with the fig-8 (MKH30) side mic, to determine the overall stereo pickup area and mid focus I want. Hugely versatile, sounds wonderful, but an enormously expensive arrangement!
However, a single mic solution tends to be smaller and easier to accommodate on a shockmount system and windshield, which can be important for some people. And if the single stereo mic incorporates its own MS matrix you can audition normal left-right stereo directly which is handy of your recorder or mixer doesn't have MS decoding facilities.
I'm kind of confused on how can you get a M/S image with only one mic.
It's a single mic body, but inside there are two mic capsules (often three, in fact). One for the mid output (sitting at the base of the interference tube), and then either one or two capsules located directly behind it facing sideways for the Sides output.