Bosch EVF-1181S EVF-1181S-PIW User Manual

Product codes
EVF-1181S-PIW
Page of 16
EVF Constant-Directivity Waveguides
Electro-Voice developed the first “constant directivity” waveguides in the 1970s, which, unlike 
conventional devices of the day, maintained their rated coverage angles over a wide frequency 
range. EV constant directivity meant that anyone seated in the waveguide’s pattern received the 
same frequency balance as anyone else, a great boon in providing truly uniform coverage and 
sound quality across a venue.
Today’s EVF waveguides incorporate the design refinements of over 30 years’ development. Their 
square mouths make all seven EVF coverage patterns rotatable, so that enclosure orientation 
is independent of the desired horizontal coverage pattern. Their 12-inch mouth size is a good 
match to the EVF’s 12- and 15-inch woofers, allowing modest overall enclosure dimensions. This 
size is also large enough to provide pattern control well into the critical midrange frequencies, 
appropriate for acoustically well-behaved spaces. (For venues with reverberation times greater 
than 2-2.5 seconds, the EVH horn-loaded series is recommended.)
EV- Innovation