Renew Your Audio Media Subscription for 2009!

The Great Divide:
Monitors Vs. Speakers
Stephen Bennett talks to Andy Munro, renowned and respected design engineer, about the
differences between monitors and speakers.
While having much in common, the
worlds of audio recording and
reproduction often seem as far
apart as the famous men and women from
Mars and Venus. The technology and physics
relating to both fields are almost identical, but
as soon as human perception rears its ugly
head the two split faster than a Hollywood
marriage. Nowhere is this more apparent than
in the field of loudspeakers – they’ve even
got different names, ‘speakers’ in the hi-fi
world, and ‘monitors’ in the recording
studio. But aren’t the two products
just the same really, with the only
differences being cosmetic?
Studio monitors tend to be
ruggedly built with magnetic
shielding, while hi-fi speakers are
usually designed to fit into a home
environment and so usually sport
wood veneers and fine polish.
The situation is further
blurred by the fact that many
prominent studio and mastering
engineers use speakers
designed for home use in their
studios, while you can often
find a pair of well respected
studio monitors in front of the
serious audiophile’s settee.
Other differences between
monitors and speakers destined
for the home often seem trivial;
monitors are often advertised with exacting
paper specification charts, while their
hi-fi brethren are often more likely to be
described by epithets such as ‘neutral’,
‘pace-y’, or ‘having a good bass response.’
In fact, may hi-fi speaker manufacturers
say that specifications, beyond the basics
of power handling and frequency plots, are
worthless, and the only way to choose a
speaker is to audition them in your home.
Monitors are often said to be designed to be
‘accurate’, while hi-fi speakers may have a
‘sound’ – but sometimes two products from
the same manufacturers are described
in both fashions – when in effect they are
basically the same speaker! When it comes
to the crunch, both studio monitors and hifi
speakers are basically just some drivers
mounted in a box – so is there anything that
is really distinctive about a studio monitor as
opposed to a speaker destined for the home?
To answer this question I turned to one of
the most respected monitor and studio design
engineers in the business. Andy Munro has
been working in the field of
“Some hi-fi
companies offer
‘matched’ pairs
of speakers, but
two wrongs don’t
make a right
because any
one pair will be
different from any
other – and God
help you if you
blow a driver!”
6 THE GREAT DIVIDE
acoustic engineering since
the 1970s and has designed
and installed monitor systems
in many studios, including
Peter Gabriel’s Real World,
along with one of the largest
in Europe, Puck studios in
Denmark. “We’ve done a lot
of independents as well,”
says Munro.” The company
was growing at a time when
the independent recording
sector was burgeoning.
I worked very closely with
record producer Mike Hedges,
and through that got involved
with the likes of Souxsie and
the Banshees, Manic Street
Preachers, and Travis.
In The Eyes of The Beholder
As for studio monitors, Munro turns to the
visual world to describe the differences
between the studio speaker and its homebased
counterpart. “It’s relatively simple
really – you can use the analogy of a video
monitor to demonstrate the differences.
A video monitor has to truly represent all
the visual frequencies in the spectrum in as
even a way as is possible. So if you imagine
a sound spectrum as if it were a colour one,
it’s got to go all the way from red to violet –
perhaps right even up to the UV range, with no
distortion of the spectrum and with a relatively
flat response at all intensities of brightness.
A lot of [‘hi-fi’] speakers are tweaked to
give you a very flat on axis response, which
looks great on paper, but because of the
enhanced directivity say, or because of the
way the frontal radiation of the speaker has
been tweaked, it won’t necessarily give you
a balanced sound in a room. Munro believes
this is why so many speaker systems sound
different even when using similar components.
“It’s the difference in the power response and
not the frequency response,” he says.
“What happens in the acoustic domain is
that you don’t just hear the direct sound of
the speaker. People talk about ‘near -field’
speakers as if they were anechoic almost by
definition – which implies that there is no
far-field response – but that’s just not true.
You only have to be one metre from a speaker,
and the wave-front emanating from the unit
at low frequencies is something like thirteen
square metres, so you can see that 99 percent
of the energy is going into the room rather
than direct to your ear – which of course is
much smaller than the room!
So at low frequencies you have a room
response whether you like it or not. A speaker
may be very directional at high frequencies
and may sound like it’s in your face but, in
reality, the balance may be completely wrong,
with most of the lower frequencies coming
off the walls. A less directional speaker gives
a more even room response, and more of a
complete balance between direct and reflected
energy. With a directional speaker some
equalisation is inevitable – hence the ‘X’
curve in film dubbing theatres.”
Start At The End
So, beginning with this simple premise,
Munro designs his speakers by starting
from exactly the opposite way you’d expect.
“We do things backwards!” he laughs, “We