One of the prime uses for boundary microphones is the amplification and recording of acoustic pianos. The size, complexity and wide frequency range of the piano makes it a challenging instrument to mic and, short of a complex, professional multi-microphone setup, a good boundary mic is the best choice. The Applied Microphone Technology AMT M40 Acoustic Piano Microphone System with AP40 Preamp, for instance, provides a natural sound that's ideal for both live and studio settings and can be used in grand and upright pianos for recording everything from delicate arpeggiated passages to booming cadences.
If you're looking for a mic to use in a variety of conditions for different applications, however, you might want to try the Nady CBM 40X Boundary Microphone. This versatile mic has a wide-range back electret condenser with a cardioid polar pattern as well as rubber padding to minimize the mechanical coupling of surface vibrations. It's great for studio recording, sound reinforcement, kick drum recording and much more.
Still extremely versatile but more portable options also exist and are convenient for recording on the go. The Blue Mickey Digital iOS Recording Interface, for example, features two custom-tuned capsules in one compact mic for mobile recording on your iPod or iPhone. It simply plugs into your device and has a 230-degree rotating top, making it perfect for interviewing, concerts, dictation and lectures.
When you don't want to be lugging around multiple microphones or when you need to improve your sound reinforcement setup, a boundary mic is an excellent option. After all, getting good sound depends on the delivery, but a quality performance or recording is all about using the right equipment.