Heya,

I've been asked to help put together a new sound system for our High
School's gym. The primary function of this system will be to reinforce
speech during school assemblies, so speech intelligibility is very
important. Music doesn't sound too great on our current horn loaded
center cluster so hopefully I can improve this too.

I'm not sure of the dimensions of the room. The ceiling is metal and
consists of two halves joining at the middle. The risers on either side
almost reach the ceiling so the only large parallel surfaces are the
lengthwise walls and from the edge of each bleacher step to the
corresponding edge on the other bleachers.

The guy in charge would like to purchase new speakers to fly so the
portable PA system no longer has to be hauled out and set up, so most
of our pathetic budget ($1000-$2000) will have to go to new speakers
rather than acoustical treatment. We've already got amps, cables, and a
mixing console so I'm hoping we'll have enough funds for a decent set
of speakers.

We were thinking about purchasing four two-way full range speakers with
15" woofers - would this be powerful enough? Also, would we benefit
from purchasing a DSP of some sort to RTA the system?

I'm also not sure how we should go about placing the speakers. I've
drawn up two diagrams:
http://www.pixelwrench.com/gym.jpg

The second obviously would require more equipment to process a delay to
compensate for the distance. Would either of these setups work or would
there be a better way to go about it.

Regarding the first drawing, what if I placed subwoofers between both
pairs and crossed the 'satellite' cabs over just above the sub's range?

Input is greatly appricated, I thank you in advance for any advise you
may give me!

Regards,
Matt Carpenter

wrote:

Heya,

I've been asked to help put together a new sound system for our High
School's gym. The primary function of this system will be to reinforce
speech during school assemblies, so speech intelligibility is very
important. Music doesn't sound too great on our current horn loaded
center cluster so hopefully I can improve this too.

I'm not sure of the dimensions of the room. The ceiling is metal and
consists of two halves joining at the middle. The risers on either side
almost reach the ceiling so the only large parallel surfaces are the
lengthwise walls and from the edge of each bleacher step to the
corresponding edge on the other bleachers.

The guy in charge would like to purchase new speakers to fly so the
portable PA system no longer has to be hauled out and set up, so most
of our pathetic budget ($1000-$2000) will have to go to new speakers
rather than acoustical treatment. We've already got amps, cables, and a
mixing console so I'm hoping we'll have enough funds for a decent set
of speakers.

We were thinking about purchasing four two-way full range speakers with
15" woofers - would this be powerful enough?

Why *on earth* do you think you need 15" woofers for a system that's
primarily intended for speech ?

Such a cabinet will sound truly dreadful for speech use.

Sounds to me like you're no expert and ought to back out of this before you
end up taking the flack for the poor result that often results from a
situation with inadequate budget that inexperienced ppl are trying to put
together on the cheap. It invariably ends in tesrs.

Graham

wrote in message
oups.com
Heya,

I've been asked to help put together a new sound system
for our High School's gym. The primary function of this
system will be to reinforce speech during school
assemblies, so speech intelligibility is very important.
Music doesn't sound too great on our current horn loaded
center cluster so hopefully I can improve this too.

I'm not sure of the dimensions of the room. The ceiling
is metal and consists of two halves joining at the
middle. The risers on either side almost reach the
ceiling so the only large parallel surfaces are the
lengthwise walls and from the edge of each bleacher step
to the corresponding edge on the other bleachers.

The guy in charge would like to purchase new speakers to
fly so the portable PA system no longer has to be hauled
out and set up, so most of our pathetic budget
($1000-$2000) will have to go to new speakers rather than
acoustical treatment. We've already got amps, cables, and
a mixing console so I'm hoping we'll have enough funds
for a decent set of speakers.

The key design goal of a SR system that plays in a highly
reverberent room is loudspeaker directivity control.

In the area of directivity control, the most important thing
to do is to avoid exciting areas like 2- and 3-surface
corners that tend to concentrate the sound, particularly
such areas that would exist in opposing pairs, or that would
focus the sound back at the area where the mics are placed.

This requires considerable attention to speaker selection,
placement, and orientation.

The modern way to accomplish this involves arrays of
speakers that are each quite directive.

If you don't do this right, fairly disasterous
(bad-sounding, low intelligibility) sound can easily be
predicted. It takes skill and experience to even step up to
jobs like this, let alone execute them.

IME the naive ways to set sound equipment up in rooms like
this (i.e, speakers mounted at a fairly low levels on cheap
stands or sitting on the floor) tend to blunder into better
results than many attempts to be clever and fly the
speakers.

I happen to do a lot of work in a room that does *all* of
the above wrong. Not nice. :-(

wrote:
Heya,

I've been asked to help put together a new sound system for our High
School's gym.

most of our pathetic budget ($1000-$2000) will have to go to new speakers
rather than acoustical treatment.

Input is greatly appricated, I thank you in advance for any advise you
may give me!

The best $1000-$2000 you can spend will be to hire someone who
understands the challenges of intelligibility in gyms, and how to
correct the room before any money is spent on electronic solutions.

If you don't get the room under control, you'll never get the speakers
right, no matter how much money you spend on them.

There are resources available, most of them contained in the brains of
skilled, knowledgeable people. Whoever's money your spending, spend it
wisely. Get the best acoustical solutions you can for the money you have
at present. Save up until you get the money to do the rest. The
immediate benefit will be that your present way of amplifying sound will
be much better. The long term benefit will be that you will have solved
a problem, and possibly be thought of as a hero.

Don't let it be said of you "We told you so."

Good luck.




TM

In article .com,
wrote:

We were thinking about purchasing four two-way full range speakers with
15" woofers - would this be powerful enough? Also, would we benefit
from purchasing a DSP of some sort to RTA the system?

Bad idea.

This is a very live room. It's supposed to be live. The fact that the
room is live makes sports events more exciting, even though it makes
for poor voice intelligibility.

The goal of systems for these rooms is to get as much sound to the
crowd and as little sound as possible anywhere else, to try and bring
the room ambience down as much as possible.

The two ways to do this are with speakers that have _very_ narrow horns
and tight pattern control, and with distributed systems that bring a
lot of small speakers as close to the listeners as possible. In most
cases, there really is going to be no way around narrow dispersion horns.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

mattcarpenter wrote ...
I've been asked to help put together a new sound system
for our High School's gym.

Run. Consider succumbing to the Avian Flu, or take an
extended vacation to the opposite end of the country.

The primary function of this system will be to reinforce
speech during school assemblies, so speech intelligibility
is very important. Music doesn't sound too great on our
current horn loaded center cluster so hopefully I can
improve this too.

Getting reasonable speech reinforcement in a room like
that is difficult enough. Getting good music reproduction
approaches miraculous. Even at 20x your budget, especially
without doing something about the room.

I'm not sure of the dimensions of the room. The ceiling
is metal and consists of two halves joining at the middle.
The risers on either side almost reach the ceiling so the
only large parallel surfaces are the lengthwise walls and
from the edge of each bleacher step to the corresponding
edge on the other bleachers.

They never put chairs into the main floor for more
conventional, auditorium-like seating? Is there a stage (or
apparent source) at one end or the other? Is this just for
game announcements, or for programs also?

The guy in charge would like to purchase new speakers
to fly so the portable PA system no longer has to be hauled
out and set up, so most of our pathetic budget ($1000-$2000)
will have to go to new speakers rather than acoustical
treatment. We've already got amps, cables, and a mixing
console so I'm hoping we'll have enough funds for a decent
set of speakers.

I wouldn't even bother. Your budget might as well be $100.
If all you want to do is spend $1-2K on speakers, you will
be just wasting the money with no significant improvement
in sound. I don't mean to sound negative, but most of the
people here have seen this exact scenario many times before
and the outcome is rarely satisfying.

We were thinking about purchasing four two-way full
range speakers with 15" woofers - would this be powerful
enough?

You appear to be shooting in the dark with speaker selection.
At least with the information you have provided.

Also, would we benefit from purchasing a DSP
of some sort to RTA the system?

No amount of DSP will solve the acoustic nightmare.

I'm also not sure how we should go about placing the speakers.
I've drawn up two diagrams:
http://www.pixelwrench.com/gym.jpg

The second obviously would require more equipment to
process a delay to compensate for the distance. Would
either of these setups work or would there be a better
way to go about it.

Compensate for the distance from what? If the apparent
source is the basketball official standing at center-court,
it is not clear that any delay is needed. If the apparent
source is on stage at one end, then that is a diffrent matter.
But your diagrams don't indicate that kind of use?

Regarding the first drawing, what if I placed subwoofers
between both pairs and crossed the 'satellite' cabs over
just above the sub's range?

Subwoofers would just add insult to injury without some
acoustic control.

Input is greatly appricated, I thank you in advance for any
advise you may give me!

You may not like the input/advice, but if you are wise, you
will take it back to them and recommend a reality check.

IME the naive ways to set sound equipment up in rooms like
this (i.e, speakers mounted at a fairly low levels on cheap
stands or sitting on the floor) tend to blunder into better
results than many attempts to be clever and fly the
speakers.

Sometimes this is not naive at all, & achieves, (not blunders into in
any sense,) exactly what the engineer/sound designer had hoped for, as
in a Kronos gig at a fine arts high school gym in Arkansas earlier this
year. Then again, groundstacking the PA is an underlined capitalized
item in our tech rider anyway.
Scott Fraser

One fairly large curtain over the back wall may be all that's needed. We've
even screwed office gobos to a 2x4 strung acrass the back wall(very cheap!)
with more than acceptable results. You don't need to spend thousands to get
a significant acoustic improvement.

Rick Hollett
"Richard Crowley" wrote in message
...
mattcarpenter wrote ...
I've been asked to help put together a new sound system for our High
School's gym.

Run. Consider succumbing to the Avian Flu, or take an
extended vacation to the opposite end of the country.

The primary function of this system will be to reinforce
speech during school assemblies, so speech intelligibility is very
important. Music doesn't sound too great on our current horn loaded
center cluster so hopefully I can improve this too.

Getting reasonable speech reinforcement in a room like that is difficult
enough. Getting good music reproduction approaches miraculous. Even at 20x
your budget, especially
without doing something about the room.

I'm not sure of the dimensions of the room. The ceiling is metal and
consists of two halves joining at the middle. The risers on either side
almost reach the ceiling so the only large parallel surfaces are the
lengthwise walls and from the edge of each bleacher step to the
corresponding edge on the other bleachers.

They never put chairs into the main floor for more conventional,
auditorium-like seating? Is there a stage (or
apparent source) at one end or the other? Is this just for
game announcements, or for programs also?

The guy in charge would like to purchase new speakers to fly so the
portable PA system no longer has to be hauled out and set up, so most of
our pathetic budget ($1000-$2000) will have to go to new speakers rather
than acoustical treatment. We've already got amps, cables, and a mixing
console so I'm hoping we'll have enough funds for a decent set of
speakers.

I wouldn't even bother. Your budget might as well be $100.
If all you want to do is spend $1-2K on speakers, you will
be just wasting the money with no significant improvement
in sound. I don't mean to sound negative, but most of the
people here have seen this exact scenario many times before and the
outcome is rarely satisfying.

We were thinking about purchasing four two-way full range speakers with
15" woofers - would this be powerful enough?

You appear to be shooting in the dark with speaker selection.
At least with the information you have provided.

Also, would we benefit from purchasing a DSP of some sort to RTA the
system?

No amount of DSP will solve the acoustic nightmare.

I'm also not sure how we should go about placing the speakers. I've drawn
up two diagrams:
http://www.pixelwrench.com/gym.jpg

The second obviously would require more equipment to process a delay to
compensate for the distance. Would either of these setups work or would
there be a better way to go about it.

Compensate for the distance from what? If the apparent source is the
basketball official standing at center-court, it is not clear that any
delay is needed. If the apparent source is on stage at one end, then that
is a diffrent matter. But your diagrams don't indicate that kind of use?

Regarding the first drawing, what if I placed subwoofers between both
pairs and crossed the 'satellite' cabs over just above the sub's range?

Subwoofers would just add insult to injury without some
acoustic control.

Input is greatly appricated, I thank you in advance for any
advise you may give me!

You may not like the input/advice, but if you are wise, you
will take it back to them and recommend a reality check.

On 12/4/05 9:28 AM, in article , "Scott Dorsey"
wrote:

In article .com,
wrote:

We were thinking about purchasing four two-way full range speakers with
15" woofers - would this be powerful enough? Also, would we benefit
from purchasing a DSP of some sort to RTA the system?

Bad idea.

This is a very live room. It's supposed to be live. The fact that the
room is live makes sports events more exciting, even though it makes
for poor voice intelligibility.

The goal of systems for these rooms is to get as much sound to the
crowd and as little sound as possible anywhere else, to try and bring
the room ambience down as much as possible.

The two ways to do this are with speakers that have _very_ narrow horns
and tight pattern control, and with distributed systems that bring a
lot of small speakers as close to the listeners as possible. In most
cases, there really is going to be no way around narrow dispersion horns.


http://www.bose.com/controller?event...l=/professiona
l/systems/schools/mariucci.jsp&ck=0