"Randy Yates" wrote in message
news
Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

Is this a bad idea? Are there other considerations to be made?
Any comments otherwise?

Without more details, it's impossible comment on the proposed speaker
system.

I get this feeling that you are trying to set up an distributed array, not a
line array or a concentrated array. These are each, very different things.

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs). Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

You will need also an
amplifier that can give N+ times the desired power in each peaker.

Right. Thanks for your comments, Remberto.

---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

--Randy Yates

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs). Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

You will need also an
amplifier that can give N+ times the desired power in each peaker.

Right. Thanks for your comments, Remberto.

---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

--Randy Yates

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs). Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

You will need also an
amplifier that can give N+ times the desired power in each peaker.

Right. Thanks for your comments, Remberto.

---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

--Randy Yates

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs). Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

You will need also an
amplifier that can give N+ times the desired power in each peaker.

Right. Thanks for your comments, Remberto.

---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

--Randy Yates

Randy Yates wrote:

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs).

If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)? For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should see
it. Or let N=1, you are left with Rt=1.

Randy Yates wrote:

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs).

If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)? For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should see
it. Or let N=1, you are left with Rt=1.

Randy Yates wrote:

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs).

If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)? For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should see
it. Or let N=1, you are left with Rt=1.

Randy Yates wrote:

El Meda wrote in message . ..
Randy Yates wrote:

Randy Yates writes:

Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

I just realized this is wrong.

On the contrary, this is right.

The total impedance Rs of N identical networks of impedance R in series is N * R.
The total impedance Rp of N identical networks of impedance Rs in parallel is
Rs^N / (N * Rs).

If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)? For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is

Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)

Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should see
it. Or let N=1, you are left with Rt=1.

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

chung writes:
[...]
If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)?

By forgetting Circuit Analysis 101. Wow, this is incredible.

I was misremembering that N resistors in parallel had total
resistance R1*R2*...*RN/(R1 + R2 + ... + RN). I don't know
where that come from, cause it's wrong.

For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is
Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)
Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should
see it. Or let N=1, you are left with Rt=1.

Yep. Problem is, you don't think to check these things if you
don't know you've made a mistake.
--
% Randy Yates % "I met someone who looks alot like you,
%% Fuquay-Varina, NC % she does the things you do,
%%% 919-577-9882 % but she is an IBM."
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

chung writes:
[...]
If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)?

By forgetting Circuit Analysis 101. Wow, this is incredible.

I was misremembering that N resistors in parallel had total
resistance R1*R2*...*RN/(R1 + R2 + ... + RN). I don't know
where that come from, cause it's wrong.

For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is
Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)
Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should
see it. Or let N=1, you are left with Rt=1.

Yep. Problem is, you don't think to check these things if you
don't know you've made a mistake.
--
% Randy Yates % "I met someone who looks alot like you,
%% Fuquay-Varina, NC % she does the things you do,
%%% 919-577-9882 % but she is an IBM."
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

chung writes:
[...]
If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)?

By forgetting Circuit Analysis 101. Wow, this is incredible.

I was misremembering that N resistors in parallel had total
resistance R1*R2*...*RN/(R1 + R2 + ... + RN). I don't know
where that come from, cause it's wrong.

For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is
Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)
Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should
see it. Or let N=1, you are left with Rt=1.

Yep. Problem is, you don't think to check these things if you
don't know you've made a mistake.
--
% Randy Yates % "I met someone who looks alot like you,
%% Fuquay-Varina, NC % she does the things you do,
%%% 919-577-9882 % but she is an IBM."
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

chung writes:
[...]
If you have N impedances in parallel, and each of those impedances is
Rs, then the resultant impedance is Rs/N. How did you come up with
Rs^N/(N*Rs)?

By forgetting Circuit Analysis 101. Wow, this is incredible.

I was misremembering that N resistors in parallel had total
resistance R1*R2*...*RN/(R1 + R2 + ... + RN). I don't know
where that come from, cause it's wrong.

For one thing, the dimension is clearly wrong!

I assume that ^ means raised to the power.

Thus the total impedance is
Rt = (N * R)^N / (N * N * R)
= (N^N) * R^N / (N^2 * R)
= N^(N - 2) * R^(N - 1)
Thus Rt = R iff N = 2.

A simple dimension check shows you are wrong. Let N=3 and you should
see it. Or let N=1, you are left with Rt=1.

Yep. Problem is, you don't think to check these things if you
don't know you've made a mistake.
--
% Randy Yates % "I met someone who looks alot like you,
%% Fuquay-Varina, NC % she does the things you do,
%%% 919-577-9882 % but she is an IBM."
%%%% % 'Yours Truly, 2095', *Time*, ELO
http://home.earthlink.net/~yatescr

"Arny Krueger" writes:
Without more details, it's impossible comment on the proposed speaker
system.

Impossible? That seems a bit over the top, Arny. What details do you need?
It's a large room which I want to put sound into.

I get this feeling that you are trying to set up an distributed array, not a
line array or a concentrated array. These are each, very different things.

If I understand your terms correctly, you are correct. I'm considering
a two-dimensional array of speakers, like in an office building or
restaurant.
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

"Arny Krueger" writes:
Without more details, it's impossible comment on the proposed speaker
system.

Impossible? That seems a bit over the top, Arny. What details do you need?
It's a large room which I want to put sound into.

I get this feeling that you are trying to set up an distributed array, not a
line array or a concentrated array. These are each, very different things.

If I understand your terms correctly, you are correct. I'm considering
a two-dimensional array of speakers, like in an office building or
restaurant.
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

"Arny Krueger" writes:
Without more details, it's impossible comment on the proposed speaker
system.

Impossible? That seems a bit over the top, Arny. What details do you need?
It's a large room which I want to put sound into.

I get this feeling that you are trying to set up an distributed array, not a
line array or a concentrated array. These are each, very different things.

If I understand your terms correctly, you are correct. I'm considering
a two-dimensional array of speakers, like in an office building or
restaurant.
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

"Arny Krueger" writes:
Without more details, it's impossible comment on the proposed speaker
system.

Impossible? That seems a bit over the top, Arny. What details do you need?
It's a large room which I want to put sound into.

I get this feeling that you are trying to set up an distributed array, not a
line array or a concentrated array. These are each, very different things.

If I understand your terms correctly, you are correct. I'm considering
a two-dimensional array of speakers, like in an office building or
restaurant.
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.
---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.
---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.
---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.
---
Ing. Remberto Gomez-Meda
http://ingemeda.tripod.com/
INGE - Ingenieria Electronica.
Puerto Vallarta, Jalisco, Mexico.

(unitron) writes:

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

(unitron) writes:

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

(unitron) writes:

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

(unitron) writes:

"Rich Andrews." wrote in message . 3.44...

---snip---
Suffice to say that no matter what happens, that little old lady that
always sits in the back will be unhappy. Jesus himself could stand in
front of her preaching and she couldn't hear or understand what he is
saying.

If you want to make that little old lady happy check out the
Assisted Listening things that transmit FM in that 4 MHz gap between
VHF television channel 4 and channel 5. You get a transmitter and
some little receivers like little transistor radios from days gone by
that have a jack for those little in-ear earphones. Send it a
vocal-heavy mix and she'll think you're a mracle worker.

--
Randy Yates
Sony Ericsson Mobile Communications
Research Triangle Park, NC, USA
, 919-472-1124

Randy Yates wrote:

Thanks Rich - reading the papers now. I have since seen the
70-volt distribution idea, which I am tending away from due
to the extra expense and inefficiencies of the transformers.

In terms of amount of copper to purchase it probably is the cheapest
option.

I did a not totally dissimilar research about a year ago, back then
Tannoy 8" boxes came out on top, based on specs and cost. Unfortunately
a sponsor donated something otherwise good, but totally useless,
instead. Tannoy do have at least one 8" box for 70 volts. Nag me if I
should look through it, I had to consider weatherproofing too, choices
may be different if that is not required.

--Randy


Kind regards

Peter Larsen



--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Randy Yates wrote:

Thanks Rich - reading the papers now. I have since seen the
70-volt distribution idea, which I am tending away from due
to the extra expense and inefficiencies of the transformers.

In terms of amount of copper to purchase it probably is the cheapest
option.

I did a not totally dissimilar research about a year ago, back then
Tannoy 8" boxes came out on top, based on specs and cost. Unfortunately
a sponsor donated something otherwise good, but totally useless,
instead. Tannoy do have at least one 8" box for 70 volts. Nag me if I
should look through it, I had to consider weatherproofing too, choices
may be different if that is not required.

--Randy


Kind regards

Peter Larsen



--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Randy Yates wrote:

Thanks Rich - reading the papers now. I have since seen the
70-volt distribution idea, which I am tending away from due
to the extra expense and inefficiencies of the transformers.

In terms of amount of copper to purchase it probably is the cheapest
option.

I did a not totally dissimilar research about a year ago, back then
Tannoy 8" boxes came out on top, based on specs and cost. Unfortunately
a sponsor donated something otherwise good, but totally useless,
instead. Tannoy do have at least one 8" box for 70 volts. Nag me if I
should look through it, I had to consider weatherproofing too, choices
may be different if that is not required.

--Randy


Kind regards

Peter Larsen



--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

Randy Yates wrote:

Thanks Rich - reading the papers now. I have since seen the
70-volt distribution idea, which I am tending away from due
to the extra expense and inefficiencies of the transformers.

In terms of amount of copper to purchase it probably is the cheapest
option.

I did a not totally dissimilar research about a year ago, back then
Tannoy 8" boxes came out on top, based on specs and cost. Unfortunately
a sponsor donated something otherwise good, but totally useless,
instead. Tannoy do have at least one 8" box for 70 volts. Nag me if I
should look through it, I had to consider weatherproofing too, choices
may be different if that is not required.

--Randy


Kind regards

Peter Larsen



--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************

El Meda writes:

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.

Good ideas. Thanks, Remberto!
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

El Meda writes:

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.

Good ideas. Thanks, Remberto!
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

El Meda writes:

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.

Good ideas. Thanks, Remberto!
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

El Meda writes:

(Randy Yates) wrote:

I suggest however that you connect the
N speakers in each column in parallel, and then each parallel array in
series with each other. That way, if one of the speakers goes bad and
opens, it won't mute the entire column it is in.

But then you have the alternate problem - one speaker which shorts will
take down the whole array. But thank you for provoking some more thought
on the matter.

Not the whole array, only the column it's in: the total impedance will
only be reduced by R/N. Besides in my experience the speaker won't
usually short, and frequently open.

Good ideas. Thanks, Remberto!
--
% Randy Yates % "Bird, on the wing,
%% Fuquay-Varina, NC % goes floating by
%%% 919-577-9882 % but there's a teardrop in his eye..."
%%%% % 'One Summer Dream', *Face The Music*, ELO
http://home.earthlink.net/~yatescr

Hey Unitron,

Sorry for the late response.

(unitron) writes:

Randy Yates wrote in message ...
Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

Is this a bad idea? Are there other considerations to be made?
Any comments otherwise?

Fellow NC resident (and church sound guy) here. I suppose you can do
the series/parallel thing with an almost infinite even number of
speakers, but you'll probably need to divide the total number of
speakers into the output wattage of the amp to see if each speaker
will get enough wattage to drive them all.

Yeah, but that's true in some sense anyway. That is, the basically
problem of having a lot of speakers and the corresponding amount of
power to drive them to usable levels is going to be there no matter
what interface (70V or series/parallel) you use.

Also, if all these
speakers are going to be in the same room, like say the sanctuary or
fellowship hall, you may find that the acoustic properties of the room
may require that not all the speakers run at the same volume.

What acoustic conditions could result in this scenario? I could see it
if the room was irregular (especially if the ceiling was lower in some
sections).

On the
other hand if you're looking to distribute sound to several different
rooms like the vestibule, choir room, bridal room, nursery, etc., then
a 70 Volt system is pretty much the only way to go.

We do want to include those rooms. That could be a deciding factor.

You may want to
consult a professional sound contractor. Tri-Tronics over in
Lillington (910-893-4183) have been at it a long time and seem to have
some idea what they're doing.

Thanks, but I think I'd like to keep it DIY. I've got a couple degrees
in electrical engineering, so I oughta' be able to handle it. But
thanks for the reference. Could you believe that our pastor was just
going to go out and buy another couple of speakers to replace some
oldies we have hanging up front and call it good? And one of his main
concerns was feedback while in front of the pulpit for communion!

Speaking of feedback, it seems that an array is going to be better
than two up-front speakers, no? Because the loop gain from the
microphone through the system and back is going to be less since the
power is distributed spatially over all the speakers and only a few
speakers in the array will be significant in the acoustic path.
--
% Randy Yates % "How's life on earth?
%% Fuquay-Varina, NC % ... What is it worth?"
%%% 919-577-9882 % 'Mission (A World Record)',
%%%% % *A New World Record*, ELO
http://home.earthlink.net/~yatescr

Hey Unitron,

Sorry for the late response.

(unitron) writes:

Randy Yates wrote in message ...
Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

Is this a bad idea? Are there other considerations to be made?
Any comments otherwise?

Fellow NC resident (and church sound guy) here. I suppose you can do
the series/parallel thing with an almost infinite even number of
speakers, but you'll probably need to divide the total number of
speakers into the output wattage of the amp to see if each speaker
will get enough wattage to drive them all.

Yeah, but that's true in some sense anyway. That is, the basically
problem of having a lot of speakers and the corresponding amount of
power to drive them to usable levels is going to be there no matter
what interface (70V or series/parallel) you use.

Also, if all these
speakers are going to be in the same room, like say the sanctuary or
fellowship hall, you may find that the acoustic properties of the room
may require that not all the speakers run at the same volume.

What acoustic conditions could result in this scenario? I could see it
if the room was irregular (especially if the ceiling was lower in some
sections).

On the
other hand if you're looking to distribute sound to several different
rooms like the vestibule, choir room, bridal room, nursery, etc., then
a 70 Volt system is pretty much the only way to go.

We do want to include those rooms. That could be a deciding factor.

You may want to
consult a professional sound contractor. Tri-Tronics over in
Lillington (910-893-4183) have been at it a long time and seem to have
some idea what they're doing.

Thanks, but I think I'd like to keep it DIY. I've got a couple degrees
in electrical engineering, so I oughta' be able to handle it. But
thanks for the reference. Could you believe that our pastor was just
going to go out and buy another couple of speakers to replace some
oldies we have hanging up front and call it good? And one of his main
concerns was feedback while in front of the pulpit for communion!

Speaking of feedback, it seems that an array is going to be better
than two up-front speakers, no? Because the loop gain from the
microphone through the system and back is going to be less since the
power is distributed spatially over all the speakers and only a few
speakers in the array will be significant in the acoustic path.
--
% Randy Yates % "How's life on earth?
%% Fuquay-Varina, NC % ... What is it worth?"
%%% 919-577-9882 % 'Mission (A World Record)',
%%%% % *A New World Record*, ELO
http://home.earthlink.net/~yatescr

Hey Unitron,

Sorry for the late response.

(unitron) writes:

Randy Yates wrote in message ...
Hello,

Our church is considering installing an array of single-driver,
in-ceiling speakers. It would seem that, given N^2 speakers,
configuring an N by N array in which N columns were connected
in parallel with each of the N speakers in a column connected
in series would be the way to go. This would provide the amplifier
with the impedance of one speaker and would evenly divide the
power among the N^2 speakers.

Is this a bad idea? Are there other considerations to be made?
Any comments otherwise?

Fellow NC resident (and church sound guy) here. I suppose you can do
the series/parallel thing with an almost infinite even number of
speakers, but you'll probably need to divide the total number of
speakers into the output wattage of the amp to see if each speaker
will get enough wattage to drive them all.

Yeah, but that's true in some sense anyway. That is, the basically
problem of having a lot of speakers and the corresponding amount of
power to drive them to usable levels is going to be there no matter
what interface (70V or series/parallel) you use.

Also, if all these
speakers are going to be in the same room, like say the sanctuary or
fellowship hall, you may find that the acoustic properties of the room
may require that not all the speakers run at the same volume.

What acoustic conditions could result in this scenario? I could see it
if the room was irregular (especially if the ceiling was lower in some
sections).

On the
other hand if you're looking to distribute sound to several different
rooms like the vestibule, choir room, bridal room, nursery, etc., then
a 70 Volt system is pretty much the only way to go.

We do want to include those rooms. That could be a deciding factor.

You may want to
consult a professional sound contractor. Tri-Tronics over in
Lillington (910-893-4183) have been at it a long time and seem to have
some idea what they're doing.

Thanks, but I think I'd like to keep it DIY. I've got a couple degrees
in electrical engineering, so I oughta' be able to handle it. But
thanks for the reference. Could you believe that our pastor was just
going to go out and buy another couple of speakers to replace some
oldies we have hanging up front and call it good? And one of his main
concerns was feedback while in front of the pulpit for communion!

Speaking of feedback, it seems that an array is going to be better
than two up-front speakers, no? Because the loop gain from the
microphone through the system and back is going to be less since the
power is distributed spatially over all the speakers and only a few
speakers in the array will be significant in the acoustic path.
--
% Randy Yates % "How's life on earth?
%% Fuquay-Varina, NC % ... What is it worth?"
%%% 919-577-9882 % 'Mission (A World Record)',
%%%% % *A New World Record*, ELO
http://home.earthlink.net/~yatescr