The shape and construction of the control room is crucial if you want to get any idea of how a recording is going to sound when it gets onto someones stereo. A control room, (unless very large) should be dead - no reverberation of any kind - nor should there be any serious standing waves at bass frequencies. A control room which looks like it has been built from the ground up as opposed to a room in a house or shed with a bit of padding on the walls, will always be a better bet and shows that the studio proprietor is serious about quality.
Recording Console - Mixer
Because of the number of mics required for drums alone, it is impossible to get a decent result without using a studio with a proper high quality mixing desk with a comprehensive patch bay. It should have a good range of dynamics (Compressors and Gates), at least one state-of-the-art reverb, and decent flattering monitoring which should include both near field and room monitors (speakers).
Professional Audio Mixers
Common Manufacturers Of High Quality are: API, Amek, Trident, Audient, Cadac, Sony, SSL, Trident, Yamaha, Mackie, Tascam and Digidesign - Protools (Big Systems Only).
Caution: Mackie, Souncraft, Yamaha and Tascam also make very good Mixers. They also make budget desks and live mixers which are not suitable.
Manufacturers such as Behringer, Alesis, Phonic, Tapco and Studiomaster do not make recording consoles for professional use.
Other absolute musts are compressors and gates. A good studio will have at least eight gates available, though in hi-end DAWs such as Cubase, Nuendo, Logic or Protools, the software dynamics are now very good.
A studio must have at least two up market stereo valve compressors (or two matched mono units with a link) plus a handful of various other types. All sound different, and all have their uses.
It should also have a dedicated vocal dynamics processor which I deal with in a bit more detail below.