L-Acoustics dV-DOSC Operator's Manual page 13

correctly focussing the system on the audience - this is the benefit of WST and also the reason why
correct focus of the system on the audience area is so important.
Psychoacoustically, nearfield extension allows one to walk a considerable distance from a dV-DOSC
system with only a small difference in SPL due to the system's unconventional attenuation rate.
Effectively, more of the audience experiences nearfield listening, enjoying higher fidelity, improved
stereo imaging and exceptional clarity. Subjectively, the loudspeakers seem much closer and the
sound is ''in your face''. Image localization is towards the action on stage - not the loudspeaker
arrays. Practically, this extension of the nearfield means that extreme sound pressure levels are not
required close to the system in order to provide acceptable SPLs further back in the audience - this
is a highly desirable property that results in reduced potential for hearing loss for both audiences and
engineers.
Nearfield extension, combined with the precision and predictability of dV-DOSC coverage is also
effective in "pushing back" the critical distance in highly reverberant spaces (critical distance is
defined as the distance where the energy of the direct sound is equal to the reverberant energy). In
many situations, it is extremely important to keep energy off the roof, for example in arenas or
outdoor amphitheatres. If we can excite less room reverberation and focus more energy on the
audience, we can effectively move back the critical distance in a given room. Given the well-defined
vertical coverage of dV-DOSC, the benefits of WST become immediately obvious in comparison
with conventional systems when working in difficult rooms.
Finally, another benefit of WST is the high degree of SPL rejection that is obtained outside of the
defined wavefield. Nominally as high as 20 dB, this permits the installation of a dV-DOSC array
behind or above microphones with exceptionally high feedback immunity. Basically, if you can see
the bottom of the bottom enclosure of the array, you are outside of the coverage pattern (actually,
you are 3.75 degrees outside the coverage pattern – more on this later!). Monitor engineers also
enjoy working with dV-DOSC FOH systems since there is very little backwave on stage - even at
lower frequencies due to the coplanar symmetric arrangement and vertical line array configuration
of the mid/low section. High SPL rejection outside of the defined coverage region also makes dV-
DOSC an excellent solution in situations where environmental noise control is an issue, for example,
in situations where outdoor amphitheatres are located close to residential areas.
The accuracy, flexibility and predictability inherent in WST and the dV-DOSC approach to sound
reinforcement opens up many new horizons for sound design.
dV-DOSC dV-SUB Manual V2.0 Nov 2001 13