The 134 dB SPL handling of the high sensitivity 4090 means it can be used with essentially any instrument from acoustic guitar and strings to piano and wind instruments.
 
Meanwhile, the 144 dB SPL handling of the low sensitivity 4091 means it can meet just about any challenge including miking an electric guitar amp. It is an excellent microphone choice for percussion, wind, and string instruments.
 
Due to their remarkably linear frequency response in the 20 Hz to 20 kHz range, sound system engineers can also use these mics for sound system alignment, testing and tuning.

The DPA 4090 series are high quality omnidirectional condenser microphones. Due to the uniquely natural and open sound, they are suitable for instrument miking applications in the studio or on the stage.

Frequency response and directional characteristics of the 4090 microphones. Go...

Feature: 4090s in use in Holland for acoustic measurement, and for recording Bach. Go...