ACOUSTICS
and Architectural Design, which is published
by Springer Verlag.
“The results point out that for a hall to
function optimally for pop and rock music,
the RT at low frequencies needs to be just 50%
of what it needs to be for a chamber music
setting, and perhaps 60% of the ideal RT at low
frequencies for a brass band,” explains Adelman-
Larsen. “As an example, a 5,000m3 (175,000ft3)
hall would need a two-second RT for chamber
music, a 1.7-second RT for a brass band and an
RT of just one second for pop and rock music,
all at low frequencies.”
He adds that RT should not be lowered
more at high frequencies than it is for low ones,
because an audience and the air absorb a lot of
high frequency sound. Also, the PA loudspeakers’
directivity at high frequencies is a contributor.
“At the Technical University of Denmark,
I was taught that too much high-frequency
In this conceptual 2,000m3
(70,000ft3) hall, both the
ceiling and walls feature
Evoke modules configured
for maximum variability,
and finished in black
preferred the same sort of acoustics for pop
and rock music. The sound engineers did too –
although their preferences were slightly different
from the musicians’.
Setting the standard
Those studies led to the definition of
recommended reverberation times (RTs) for halls
that present amplified music, which are being
employed by acousticians today. “I am proud that
they are part of the great Norwegian Standard
NS 8178, for instance,” says Adelman-Larsen.
The studies were published in the Journal
of the Acoustical Society of America in 2010,
in Applied Acoustics in 2018 and in Adelman-
Larsen’s book Rock and Pop Venues – Acoustic
NIELS W ADELMANLARSEN’S
CAREER
SO FAR
■■1989: Graduated
from Berklee College
of Music
■■1990: Achieved a BSc
from the Technical
University of Denmark
■■1990-2006: Worked as
a professional musician
■■2005: Founded
Flex Acoustics
■■2006: Achieved a MSc
from the Technical
University of Denmark
■■2012: Launched
the aQflex and
aQtube products
■■2017: Achieved
a PhD from Aalborg
University
■■2019: Launched Evoke
Above: The Evoke modules
can be angled to achieve
more sound diffusion, as in
this conceptual 2,000m3 hall
Above left: A graph showing
the maximum and minimum
RT for the hall in the main
image, values believed to
be ideal for pop/rock music
in a venue of this size
AUDITORIA 2019 VOLUME ONE 53