I do a fair amount of work on the prosound side, in addition
to my home audio designs. My speakers are used every
weekend in live gigs all over the country.
The key to high quality sound in a big room, like your 24 x
90 foot room, is speakers that have well-controlled
radiation patterns and smooth off-axis frequency response.
Here's why: The direct sound from the speakers, or first-
arrival sound, only dominates at close range, typically
about 5-15 feet (depending on how directional the speakers
are). Beyond that distance, the reverberant energy in the
room dominates the perceived tonal balance. And the off-
axis response is what dominates the reverberant field. So
if you want good sound for everyone else in the room, you
need speakers that do a really good job with the reverberant
field, which means they need to do a good job off-axis.
High quality PA speakers are designed to do this. So are
some home audio speakers, and they tend to look like PA
speakers. The type of radiation pattern you want depends on
where the speakers will be located. For example, if they
will be on the long wall, you'll want a much wider radiation
pattern than you would need if they were on the short wall.
In fact you might even want to use four smaller PA-style
speakers (two on each side in a splayed array) to give
adequate coverage if they will be on the long wall.
As for bi-amplifying, unless you are skilled at setting up
active crossovers, or have access to someone who is, I
recommend going with speakers that have a good passive
crossover already built in. In a high quality application
the crossover provides equalization tailored to the specific
drivers, and that's the part that takes some expertise to
get right.
The same tradeoffs exist for this application as for any
other: Box size vs bass extension vs efficiency. If you
can get away with large boxes, you'll have deeper bass
and/or higher efficiency. How important are low end
extension and SPL in this application? Does "TV"
= "action movies at high volume"?
Duke
dealer/manufacturer
to my home audio designs. My speakers are used every
weekend in live gigs all over the country.
The key to high quality sound in a big room, like your 24 x
90 foot room, is speakers that have well-controlled
radiation patterns and smooth off-axis frequency response.
Here's why: The direct sound from the speakers, or first-
arrival sound, only dominates at close range, typically
about 5-15 feet (depending on how directional the speakers
are). Beyond that distance, the reverberant energy in the
room dominates the perceived tonal balance. And the off-
axis response is what dominates the reverberant field. So
if you want good sound for everyone else in the room, you
need speakers that do a really good job with the reverberant
field, which means they need to do a good job off-axis.
High quality PA speakers are designed to do this. So are
some home audio speakers, and they tend to look like PA
speakers. The type of radiation pattern you want depends on
where the speakers will be located. For example, if they
will be on the long wall, you'll want a much wider radiation
pattern than you would need if they were on the short wall.
In fact you might even want to use four smaller PA-style
speakers (two on each side in a splayed array) to give
adequate coverage if they will be on the long wall.
As for bi-amplifying, unless you are skilled at setting up
active crossovers, or have access to someone who is, I
recommend going with speakers that have a good passive
crossover already built in. In a high quality application
the crossover provides equalization tailored to the specific
drivers, and that's the part that takes some expertise to
get right.
The same tradeoffs exist for this application as for any
other: Box size vs bass extension vs efficiency. If you
can get away with large boxes, you'll have deeper bass
and/or higher efficiency. How important are low end
extension and SPL in this application? Does "TV"
= "action movies at high volume"?
Duke
dealer/manufacturer