I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

François Yves Le Gal wrote:
On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation software deal with arrays, and, that, at the commercial
level, the excellent so-called "Bessel array" is covered by a number
of Philips patents.

I think that the basic Philips patents on Bessel arrays may have run out,
at least in the US.

http://www.ee.ic.ac.uk/hp/staff/pnay...philips091.pdf
is dated 1983 which makes publication at 20 years old of 18. It's probably
worth more searching at the US patent office to confirm.

There's a later Keele AES paper that points out that many of the Bessel
arrays that Phillips proposed, aren't really all that good. But the N=5 and
N=25 versions have withstood scrutiny.

BTW I built a Bessel array composed of 5 speakers earlier this year. It
worked as promised, and had very low lobing. It sounded very much like one
of the drivers it was composed of, only it could go louder. The practical
trick is finding drivers that will result in a useable system impedance.
There's a tendency to end up too high or too low.

The real practical problem with arrays is that as long as you can readily
obtain individual drivers that can handle more power, a small number of
drivers is the more economical way to go. Therefore, arrays end up being
chosen when high sound levels and/or controlled directivity are desired.
They are typically made up of drivers that already have very good
power-handling capacity.

François Yves Le Gal wrote:
On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation software deal with arrays, and, that, at the commercial
level, the excellent so-called "Bessel array" is covered by a number
of Philips patents.

I think that the basic Philips patents on Bessel arrays may have run out,
at least in the US.

http://www.ee.ic.ac.uk/hp/staff/pnay...philips091.pdf
is dated 1983 which makes publication at 20 years old of 18. It's probably
worth more searching at the US patent office to confirm.

There's a later Keele AES paper that points out that many of the Bessel
arrays that Phillips proposed, aren't really all that good. But the N=5 and
N=25 versions have withstood scrutiny.

BTW I built a Bessel array composed of 5 speakers earlier this year. It
worked as promised, and had very low lobing. It sounded very much like one
of the drivers it was composed of, only it could go louder. The practical
trick is finding drivers that will result in a useable system impedance.
There's a tendency to end up too high or too low.

The real practical problem with arrays is that as long as you can readily
obtain individual drivers that can handle more power, a small number of
drivers is the more economical way to go. Therefore, arrays end up being
chosen when high sound levels and/or controlled directivity are desired.
They are typically made up of drivers that already have very good
power-handling capacity.

François Yves Le Gal wrote:
On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation software deal with arrays, and, that, at the commercial
level, the excellent so-called "Bessel array" is covered by a number
of Philips patents.

I think that the basic Philips patents on Bessel arrays may have run out,
at least in the US.

http://www.ee.ic.ac.uk/hp/staff/pnay...philips091.pdf
is dated 1983 which makes publication at 20 years old of 18. It's probably
worth more searching at the US patent office to confirm.

There's a later Keele AES paper that points out that many of the Bessel
arrays that Phillips proposed, aren't really all that good. But the N=5 and
N=25 versions have withstood scrutiny.

BTW I built a Bessel array composed of 5 speakers earlier this year. It
worked as promised, and had very low lobing. It sounded very much like one
of the drivers it was composed of, only it could go louder. The practical
trick is finding drivers that will result in a useable system impedance.
There's a tendency to end up too high or too low.

The real practical problem with arrays is that as long as you can readily
obtain individual drivers that can handle more power, a small number of
drivers is the more economical way to go. Therefore, arrays end up being
chosen when high sound levels and/or controlled directivity are desired.
They are typically made up of drivers that already have very good
power-handling capacity.

François Yves Le Gal wrote:
On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation software deal with arrays, and, that, at the commercial
level, the excellent so-called "Bessel array" is covered by a number
of Philips patents.

I think that the basic Philips patents on Bessel arrays may have run out,
at least in the US.

http://www.ee.ic.ac.uk/hp/staff/pnay...philips091.pdf
is dated 1983 which makes publication at 20 years old of 18. It's probably
worth more searching at the US patent office to confirm.

There's a later Keele AES paper that points out that many of the Bessel
arrays that Phillips proposed, aren't really all that good. But the N=5 and
N=25 versions have withstood scrutiny.

BTW I built a Bessel array composed of 5 speakers earlier this year. It
worked as promised, and had very low lobing. It sounded very much like one
of the drivers it was composed of, only it could go louder. The practical
trick is finding drivers that will result in a useable system impedance.
There's a tendency to end up too high or too low.

The real practical problem with arrays is that as long as you can readily
obtain individual drivers that can handle more power, a small number of
drivers is the more economical way to go. Therefore, arrays end up being
chosen when high sound levels and/or controlled directivity are desired.
They are typically made up of drivers that already have very good
power-handling capacity.

Chris Whealy wrote in :

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.


I think something is wrong here as there are many people who use line
arrays in their home.

http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
http://diyaudio.com/forums/showthrea...758&highlight=

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W




--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

Chris Whealy wrote in :

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.


I think something is wrong here as there are many people who use line
arrays in their home.

http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
http://diyaudio.com/forums/showthrea...758&highlight=

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W




--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

Chris Whealy wrote in :

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.


I think something is wrong here as there are many people who use line
arrays in their home.

http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
http://diyaudio.com/forums/showthrea...758&highlight=

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W




--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

Chris Whealy wrote in :

Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more people
don't build or produce vertical arrays. Is it the cost involved or the size
or ??? They certainly seem to have a number of good characteristics. Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.


I think something is wrong here as there are many people who use line
arrays in their home.

http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
http://diyaudio.com/forums/showthrea...758&highlight=

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W




--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

François Yves Le Gal wrote in
:

On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation
software deal with arrays, and, that, at the commercial level, the
excellent
so-called "Bessel array" is covered by a number of Philips patents.

A Bessel array is usually a horizontal array. As far as simulation
software goes, you are correct. I have not found a room simulation
program that dealt with arrays.



They certainly seem to have a number of good characteristics.

And a number of poor ones.



Such as?

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

François Yves Le Gal wrote in
:

On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation
software deal with arrays, and, that, at the commercial level, the
excellent
so-called "Bessel array" is covered by a number of Philips patents.

A Bessel array is usually a horizontal array. As far as simulation
software goes, you are correct. I have not found a room simulation
program that dealt with arrays.



They certainly seem to have a number of good characteristics.

And a number of poor ones.



Such as?

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

François Yves Le Gal wrote in
:

On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation
software deal with arrays, and, that, at the commercial level, the
excellent
so-called "Bessel array" is covered by a number of Philips patents.

A Bessel array is usually a horizontal array. As far as simulation
software goes, you are correct. I have not found a room simulation
program that dealt with arrays.



They certainly seem to have a number of good characteristics.

And a number of poor ones.



Such as?

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

François Yves Le Gal wrote in
:

On Wed, 14 Apr 2004 04:47:48 -0000, "Rich Andrews."
wrote:

I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays.

Most people follow the herd.

Is it the cost involved or the size or ???

Both are limiting factors. You should add that very few system
simulation
software deal with arrays, and, that, at the commercial level, the
excellent
so-called "Bessel array" is covered by a number of Philips patents.

A Bessel array is usually a horizontal array. As far as simulation
software goes, you are correct. I have not found a room simulation
program that dealt with arrays.



They certainly seem to have a number of good characteristics.

And a number of poor ones.



Such as?

r


--
Nothing beats the bandwidth of a station wagon filled with DLT tapes.

Rich Andrews. wrote:

A Bessel array is usually a horizontal array.

Strange that one of the two forms of Bessel array that work well is 5 x 5.

The other Bessel array that works well, 5 in a row, has the same
directional characteristics no matter which way it's roated.

Effective Performance of Bessel Arrays 2366218 bytes (CD aes5)
Author(s): Keele, Jr., D. B.
Publication: Volume 38 Number 10 pp. 723·748; October 1990
Abstract: The Bessel array is a configuration of five, seven, or nine
identical loudspeakers in an equal-spaced line array that provides the same
overall polar pattern as a single loudspeaker of the array. The results of a
computer simulation are described, which uses point sources to determine the
effective operating frequency range, working distance, efficiency, power
handling, maximum acoustic output, efficiency·bandwidth product, and
power·bandwidth product of the array. The various Bessel configurations are
compared to one-, two-, and five-source equal-spaced equal-level
equal-polarity line arrays. As compared to a single source, a five source
Bessel array is 14% (0.6dB) more efficient, can handle 3.5 (+5.4dB) more
power, and has 4 times (+6dB) the maximum midband acoustic output power, and
is usable for omnidirectional radiation up to the frequency where the
overall length is 11 wavelengths long. As compared to a two-source
equal-level in-phase array, a five-source Bessel array is 43% (2.4dB) less
efficient, can handle 1.75 (+2.4dB) more power, has the same maximum midband
acoustic output power, and is usable for omnidirectional radiation 10 times
higher in frequency. A working distance of 20 times the length of the Bessel
array was assumed, with the length of the Bessel array (center-to-center
distance of outside sources) being four times that of the two-source array.
Analysis reveals that the three Bessel arrays have equal maximum acoustic
output, but that the five-element Bessel array has the highest efficiency
and power·bandwidth product. The seven- and nine-source Bessel arrays are
found to be effectively unusable, as compared to the five-source array, due
to much lower efficiency, requirement for more sources, and poor
high-frequency performance. Judging polar peak-to-peak ripple and
high-frequency response, the performance of the Bessel array is found to
improve in direct proportion to the working distance away from the array.
Unfortunately the phase versus direction and phase versus frequency
characteristics of the Bessel array are very nonlinear and make it difficult
to use with other sources.

Rich Andrews. wrote:

A Bessel array is usually a horizontal array.

Strange that one of the two forms of Bessel array that work well is 5 x 5.

The other Bessel array that works well, 5 in a row, has the same
directional characteristics no matter which way it's roated.

Effective Performance of Bessel Arrays 2366218 bytes (CD aes5)
Author(s): Keele, Jr., D. B.
Publication: Volume 38 Number 10 pp. 723·748; October 1990
Abstract: The Bessel array is a configuration of five, seven, or nine
identical loudspeakers in an equal-spaced line array that provides the same
overall polar pattern as a single loudspeaker of the array. The results of a
computer simulation are described, which uses point sources to determine the
effective operating frequency range, working distance, efficiency, power
handling, maximum acoustic output, efficiency·bandwidth product, and
power·bandwidth product of the array. The various Bessel configurations are
compared to one-, two-, and five-source equal-spaced equal-level
equal-polarity line arrays. As compared to a single source, a five source
Bessel array is 14% (0.6dB) more efficient, can handle 3.5 (+5.4dB) more
power, and has 4 times (+6dB) the maximum midband acoustic output power, and
is usable for omnidirectional radiation up to the frequency where the
overall length is 11 wavelengths long. As compared to a two-source
equal-level in-phase array, a five-source Bessel array is 43% (2.4dB) less
efficient, can handle 1.75 (+2.4dB) more power, has the same maximum midband
acoustic output power, and is usable for omnidirectional radiation 10 times
higher in frequency. A working distance of 20 times the length of the Bessel
array was assumed, with the length of the Bessel array (center-to-center
distance of outside sources) being four times that of the two-source array.
Analysis reveals that the three Bessel arrays have equal maximum acoustic
output, but that the five-element Bessel array has the highest efficiency
and power·bandwidth product. The seven- and nine-source Bessel arrays are
found to be effectively unusable, as compared to the five-source array, due
to much lower efficiency, requirement for more sources, and poor
high-frequency performance. Judging polar peak-to-peak ripple and
high-frequency response, the performance of the Bessel array is found to
improve in direct proportion to the working distance away from the array.
Unfortunately the phase versus direction and phase versus frequency
characteristics of the Bessel array are very nonlinear and make it difficult
to use with other sources.

Rich Andrews. wrote:

A Bessel array is usually a horizontal array.

Strange that one of the two forms of Bessel array that work well is 5 x 5.

The other Bessel array that works well, 5 in a row, has the same
directional characteristics no matter which way it's roated.

Effective Performance of Bessel Arrays 2366218 bytes (CD aes5)
Author(s): Keele, Jr., D. B.
Publication: Volume 38 Number 10 pp. 723·748; October 1990
Abstract: The Bessel array is a configuration of five, seven, or nine
identical loudspeakers in an equal-spaced line array that provides the same
overall polar pattern as a single loudspeaker of the array. The results of a
computer simulation are described, which uses point sources to determine the
effective operating frequency range, working distance, efficiency, power
handling, maximum acoustic output, efficiency·bandwidth product, and
power·bandwidth product of the array. The various Bessel configurations are
compared to one-, two-, and five-source equal-spaced equal-level
equal-polarity line arrays. As compared to a single source, a five source
Bessel array is 14% (0.6dB) more efficient, can handle 3.5 (+5.4dB) more
power, and has 4 times (+6dB) the maximum midband acoustic output power, and
is usable for omnidirectional radiation up to the frequency where the
overall length is 11 wavelengths long. As compared to a two-source
equal-level in-phase array, a five-source Bessel array is 43% (2.4dB) less
efficient, can handle 1.75 (+2.4dB) more power, has the same maximum midband
acoustic output power, and is usable for omnidirectional radiation 10 times
higher in frequency. A working distance of 20 times the length of the Bessel
array was assumed, with the length of the Bessel array (center-to-center
distance of outside sources) being four times that of the two-source array.
Analysis reveals that the three Bessel arrays have equal maximum acoustic
output, but that the five-element Bessel array has the highest efficiency
and power·bandwidth product. The seven- and nine-source Bessel arrays are
found to be effectively unusable, as compared to the five-source array, due
to much lower efficiency, requirement for more sources, and poor
high-frequency performance. Judging polar peak-to-peak ripple and
high-frequency response, the performance of the Bessel array is found to
improve in direct proportion to the working distance away from the array.
Unfortunately the phase versus direction and phase versus frequency
characteristics of the Bessel array are very nonlinear and make it difficult
to use with other sources.

Rich Andrews. wrote:

A Bessel array is usually a horizontal array.

Strange that one of the two forms of Bessel array that work well is 5 x 5.

The other Bessel array that works well, 5 in a row, has the same
directional characteristics no matter which way it's roated.

Effective Performance of Bessel Arrays 2366218 bytes (CD aes5)
Author(s): Keele, Jr., D. B.
Publication: Volume 38 Number 10 pp. 723·748; October 1990
Abstract: The Bessel array is a configuration of five, seven, or nine
identical loudspeakers in an equal-spaced line array that provides the same
overall polar pattern as a single loudspeaker of the array. The results of a
computer simulation are described, which uses point sources to determine the
effective operating frequency range, working distance, efficiency, power
handling, maximum acoustic output, efficiency·bandwidth product, and
power·bandwidth product of the array. The various Bessel configurations are
compared to one-, two-, and five-source equal-spaced equal-level
equal-polarity line arrays. As compared to a single source, a five source
Bessel array is 14% (0.6dB) more efficient, can handle 3.5 (+5.4dB) more
power, and has 4 times (+6dB) the maximum midband acoustic output power, and
is usable for omnidirectional radiation up to the frequency where the
overall length is 11 wavelengths long. As compared to a two-source
equal-level in-phase array, a five-source Bessel array is 43% (2.4dB) less
efficient, can handle 1.75 (+2.4dB) more power, has the same maximum midband
acoustic output power, and is usable for omnidirectional radiation 10 times
higher in frequency. A working distance of 20 times the length of the Bessel
array was assumed, with the length of the Bessel array (center-to-center
distance of outside sources) being four times that of the two-source array.
Analysis reveals that the three Bessel arrays have equal maximum acoustic
output, but that the five-element Bessel array has the highest efficiency
and power·bandwidth product. The seven- and nine-source Bessel arrays are
found to be effectively unusable, as compared to the five-source array, due
to much lower efficiency, requirement for more sources, and poor
high-frequency performance. Judging polar peak-to-peak ripple and
high-frequency response, the performance of the Bessel array is found to
improve in direct proportion to the working distance away from the array.
Unfortunately the phase versus direction and phase versus frequency
characteristics of the Bessel array are very nonlinear and make it difficult
to use with other sources.

Rich Andrews. wrote:

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


http://www.symphonysound.com/lit/mcintosh/XR27br.pdf

Rich Andrews. wrote:

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


http://www.symphonysound.com/lit/mcintosh/XR27br.pdf

Rich Andrews. wrote:

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


http://www.symphonysound.com/lit/mcintosh/XR27br.pdf

Rich Andrews. wrote:

http://66.216.98.167/mcprod/product_docs/XRT30br.pdf


http://www.symphonysound.com/lit/mcintosh/XR27br.pdf

I use baby line arrays in clubs and small ballrooms with great success. The
optimal minimum distance is less than 5 meters.

http://www.slsloudspeakers.com/LS869...ne%20Array.htm

http://www.padrick.net/LiveSound/SLS/LS8695.htm

http://www.ribbonloudspeakers.com/_wsn/page2.html


"Chris Whealy" wrote in message
...
Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays. Is it the cost involved or the
size
or ??? They certainly seem to have a number of good characteristics.
Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

I use baby line arrays in clubs and small ballrooms with great success. The
optimal minimum distance is less than 5 meters.

http://www.slsloudspeakers.com/LS869...ne%20Array.htm

http://www.padrick.net/LiveSound/SLS/LS8695.htm

http://www.ribbonloudspeakers.com/_wsn/page2.html


"Chris Whealy" wrote in message
...
Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays. Is it the cost involved or the
size
or ??? They certainly seem to have a number of good characteristics.
Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

I use baby line arrays in clubs and small ballrooms with great success. The
optimal minimum distance is less than 5 meters.

http://www.slsloudspeakers.com/LS869...ne%20Array.htm

http://www.padrick.net/LiveSound/SLS/LS8695.htm

http://www.ribbonloudspeakers.com/_wsn/page2.html


"Chris Whealy" wrote in message
...
Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays. Is it the cost involved or the
size
or ??? They certainly seem to have a number of good characteristics.
Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

I use baby line arrays in clubs and small ballrooms with great success. The
optimal minimum distance is less than 5 meters.

http://www.slsloudspeakers.com/LS869...ne%20Array.htm

http://www.padrick.net/LiveSound/SLS/LS8695.htm

http://www.ribbonloudspeakers.com/_wsn/page2.html


"Chris Whealy" wrote in message
...
Rich Andrews. wrote:
I have been looking at various speaker designs and wondered why more
people
don't build or produce vertical arrays. Is it the cost involved or the
size
or ??? They certainly seem to have a number of good characteristics.
Am I
missing something?

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too small
for such a speaker system. In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line array.
Our audience is only 15m away. Also, you need a fairly large
vertical height in which to hang the array, again, our building could
not accomodate such a system.

As great as they are, unless your building is acousically large, it does
not make much sense to use a line array. Alternatively, line arrays are
excellent for outdoor events.

Here in the UK, I went to a "son et lumiere" style evening at Audley End
House last summer, where there was a symphony orchestra and fireworks.
There must have been 15,000 people there that evening and on either side
of the stage was a line array column. The sound from quality was
fantastic, with very little SPL variation over the entire audience depth
(about 500m).

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Chris Whealy wrote:

The church I go to recently looked into getting a vertical
line array system, but it rapidly became apparent that our
auditorium was too small for such a speaker system.

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

In order to be in the far field, the audience should not be
closer that 25 to 30 metres from the line array.

No, only for a similarly large array.

Our audience is only 15m away.

Example, not endorsement: see http://www.slsloudspeakers.com

Also, you need a fairly large vertical height in which
to hang the array, again, our building could
not accomodate such a system.

WHAT a "such a system"?

As great as they are, unless your building is acousically
large, it does not make much sense to use a line array.

A ribbon loudspeaker constitutes A line array.

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

Chris W


Kind regards

Peter Larsen

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

Chris Whealy wrote:

The church I go to recently looked into getting a vertical
line array system, but it rapidly became apparent that our
auditorium was too small for such a speaker system.

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

In order to be in the far field, the audience should not be
closer that 25 to 30 metres from the line array.

No, only for a similarly large array.

Our audience is only 15m away.

Example, not endorsement: see http://www.slsloudspeakers.com

Also, you need a fairly large vertical height in which
to hang the array, again, our building could
not accomodate such a system.

WHAT a "such a system"?

As great as they are, unless your building is acousically
large, it does not make much sense to use a line array.

A ribbon loudspeaker constitutes A line array.

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

Chris W


Kind regards

Peter Larsen

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

Chris Whealy wrote:

The church I go to recently looked into getting a vertical
line array system, but it rapidly became apparent that our
auditorium was too small for such a speaker system.

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

In order to be in the far field, the audience should not be
closer that 25 to 30 metres from the line array.

No, only for a similarly large array.

Our audience is only 15m away.

Example, not endorsement: see http://www.slsloudspeakers.com

Also, you need a fairly large vertical height in which
to hang the array, again, our building could
not accomodate such a system.

WHAT a "such a system"?

As great as they are, unless your building is acousically
large, it does not make much sense to use a line array.

A ribbon loudspeaker constitutes A line array.

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

Chris W


Kind regards

Peter Larsen

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

Chris Whealy wrote:

The church I go to recently looked into getting a vertical
line array system, but it rapidly became apparent that our
auditorium was too small for such a speaker system.

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

In order to be in the far field, the audience should not be
closer that 25 to 30 metres from the line array.

No, only for a similarly large array.

Our audience is only 15m away.

Example, not endorsement: see http://www.slsloudspeakers.com

Also, you need a fairly large vertical height in which
to hang the array, again, our building could
not accomodate such a system.

WHAT a "such a system"?

As great as they are, unless your building is acousically
large, it does not make much sense to use a line array.

A ribbon loudspeaker constitutes A line array.

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

Chris W


Kind regards

Peter Larsen

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

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

Well, I'm only repeating what the L-Acoustic and Martin sales reps told
us when when sent them the plans of our auditorium.

What they probably omitted to tell us was that _their_ line array were
not suitable for our size auditorium, and then generalised that to line
arrays in general.

Example, not endorsement: see http://www.slsloudspeakers.com

One of our prerequisites is that whatever speakers we buy, we need to
have a trial run first to actually here what they are like in our
environment. Some companies have been willing to accommodate this,
others have not...

WHAT a "such a system"?

As shipped by L-Acoustic or Martin

A ribbon loudspeaker constitutes A line array.

Would such a setup be suitable for a church auditorium of 2,500m^3 with
the audience sitting between 4m and 15m from speakers hung from the rafters?

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

L-Acousrtic recommended that we trial some 112XT's instead of their line
array speakers. We found that whilst the sound quality could not be
faulted, the people sitting near the back (approx 12m away) had a
comfortable sound leve, whilst the people in the front got drilled.

Also the 90deg conical directivity of the 112XT's created other problems...

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

Well, I'm only repeating what the L-Acoustic and Martin sales reps told
us when when sent them the plans of our auditorium.

What they probably omitted to tell us was that _their_ line array were
not suitable for our size auditorium, and then generalised that to line
arrays in general.

Example, not endorsement: see http://www.slsloudspeakers.com

One of our prerequisites is that whatever speakers we buy, we need to
have a trial run first to actually here what they are like in our
environment. Some companies have been willing to accommodate this,
others have not...

WHAT a "such a system"?

As shipped by L-Acoustic or Martin

A ribbon loudspeaker constitutes A line array.

Would such a setup be suitable for a church auditorium of 2,500m^3 with
the audience sitting between 4m and 15m from speakers hung from the rafters?

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

L-Acousrtic recommended that we trial some 112XT's instead of their line
array speakers. We found that whilst the sound quality could not be
faulted, the people sitting near the back (approx 12m away) had a
comfortable sound leve, whilst the people in the front got drilled.

Also the 90deg conical directivity of the 112XT's created other problems...

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

Well, I'm only repeating what the L-Acoustic and Martin sales reps told
us when when sent them the plans of our auditorium.

What they probably omitted to tell us was that _their_ line array were
not suitable for our size auditorium, and then generalised that to line
arrays in general.

Example, not endorsement: see http://www.slsloudspeakers.com

One of our prerequisites is that whatever speakers we buy, we need to
have a trial run first to actually here what they are like in our
environment. Some companies have been willing to accommodate this,
others have not...

WHAT a "such a system"?

As shipped by L-Acoustic or Martin

A ribbon loudspeaker constitutes A line array.

Would such a setup be suitable for a church auditorium of 2,500m^3 with
the audience sitting between 4m and 15m from speakers hung from the rafters?

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

L-Acousrtic recommended that we trial some 112XT's instead of their line
array speakers. We found that whilst the sound quality could not be
faulted, the people sitting near the back (approx 12m away) had a
comfortable sound leve, whilst the people in the front got drilled.

Also the 90deg conical directivity of the 112XT's created other problems...

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Plain nonsense, put two loudspeakers above oneanother and you have a
vertical line array, a short one, but it is valid.

Well, I'm only repeating what the L-Acoustic and Martin sales reps told
us when when sent them the plans of our auditorium.

What they probably omitted to tell us was that _their_ line array were
not suitable for our size auditorium, and then generalised that to line
arrays in general.

Example, not endorsement: see http://www.slsloudspeakers.com

One of our prerequisites is that whatever speakers we buy, we need to
have a trial run first to actually here what they are like in our
environment. Some companies have been willing to accommodate this,
others have not...

WHAT a "such a system"?

As shipped by L-Acoustic or Martin

A ribbon loudspeaker constitutes A line array.

Would such a setup be suitable for a church auditorium of 2,500m^3 with
the audience sitting between 4m and 15m from speakers hung from the rafters?

It doesn't have to be a full size stadium PA to constitute a valid line
array, the ones used in that context are btw. bent so that the audience
can still get a balanced sound - and not an insanely loud sound - close
to their "foot".

L-Acousrtic recommended that we trial some 112XT's instead of their line
array speakers. We found that whilst the sound quality could not be
faulted, the people sitting near the back (approx 12m away) had a
comfortable sound leve, whilst the people in the front got drilled.

Also the 90deg conical directivity of the 112XT's created other problems...

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--

Chris Whealy wrote:

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too
small for such a speaker system.

That would be an economic choice, not a technical choice. Line arrays can be
made to work well in smaller rooms, but of course the line array would then
itself be smaller.

In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line
array.

Actually, there are problems with being too close to a line array of a given
size, but the problem can be solved by using a smaller array.

Our audience is only 15m away. Also, you need a fairly
large vertical height in which to hang the array, again, our building
could not accomodate such a system.

Again, the geometry of line arrays is scalable.

As great as they are, unless your building is acousically large, it
does not make much sense to use a line array. Alternatively, line
arrays are excellent for outdoor events.

I've seen line arrays used to great advantage indoors. I've sat reasonably
close to them when they were operating and they remained highly effective.

There are useful things that can be done with arrays and AFAIK only with
arrays - these people were early pioneers:

http://www.duran-audio.com/Products/Intellivox.htm

Here in the UK, I went to a "son et lumiere" style evening at Audley
End House last summer, where there was a symphony orchestra and
fireworks. There must have been 15,000 people there that evening and
on either side of the stage was a line array column. The sound from
quality was fantastic, with very little SPL variation over the entire
audience depth (about 500m).

Arrays can provide similar benefits in smaller spaces.

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Other sources:

http://www.meyersound.com/support/papers/steering/

http://www.eaw.com/products/DSA/

http://www.audiosystems.ch/live/jbl/...r_englisch.pdf

Chris Whealy wrote:

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too
small for such a speaker system.

That would be an economic choice, not a technical choice. Line arrays can be
made to work well in smaller rooms, but of course the line array would then
itself be smaller.

In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line
array.

Actually, there are problems with being too close to a line array of a given
size, but the problem can be solved by using a smaller array.

Our audience is only 15m away. Also, you need a fairly
large vertical height in which to hang the array, again, our building
could not accomodate such a system.

Again, the geometry of line arrays is scalable.

As great as they are, unless your building is acousically large, it
does not make much sense to use a line array. Alternatively, line
arrays are excellent for outdoor events.

I've seen line arrays used to great advantage indoors. I've sat reasonably
close to them when they were operating and they remained highly effective.

There are useful things that can be done with arrays and AFAIK only with
arrays - these people were early pioneers:

http://www.duran-audio.com/Products/Intellivox.htm

Here in the UK, I went to a "son et lumiere" style evening at Audley
End House last summer, where there was a symphony orchestra and
fireworks. There must have been 15,000 people there that evening and
on either side of the stage was a line array column. The sound from
quality was fantastic, with very little SPL variation over the entire
audience depth (about 500m).

Arrays can provide similar benefits in smaller spaces.

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Other sources:

http://www.meyersound.com/support/papers/steering/

http://www.eaw.com/products/DSA/

http://www.audiosystems.ch/live/jbl/...r_englisch.pdf

Chris Whealy wrote:

The church I go to recently looked into getting a vertical line array
system, but it rapidly became apparent that our auditorium was too
small for such a speaker system.

That would be an economic choice, not a technical choice. Line arrays can be
made to work well in smaller rooms, but of course the line array would then
itself be smaller.

In order to be in the far field, the
audience should not be closer that 25 to 30 metres from the line
array.

Actually, there are problems with being too close to a line array of a given
size, but the problem can be solved by using a smaller array.

Our audience is only 15m away. Also, you need a fairly
large vertical height in which to hang the array, again, our building
could not accomodate such a system.

Again, the geometry of line arrays is scalable.

As great as they are, unless your building is acousically large, it
does not make much sense to use a line array. Alternatively, line
arrays are excellent for outdoor events.

I've seen line arrays used to great advantage indoors. I've sat reasonably
close to them when they were operating and they remained highly effective.

There are useful things that can be done with arrays and AFAIK only with
arrays - these people were early pioneers:

http://www.duran-audio.com/Products/Intellivox.htm

Here in the UK, I went to a "son et lumiere" style evening at Audley
End House last summer, where there was a symphony orchestra and
fireworks. There must have been 15,000 people there that evening and
on either side of the stage was a line array column. The sound from
quality was fantastic, with very little SPL variation over the entire
audience depth (about 500m).

Arrays can provide similar benefits in smaller spaces.

Take a look at http://www.l-acoustics.com/pdfproda/wavefront.zip for
more details on the theory behind line arrays.

Other sources:

http://www.meyersound.com/support/papers/steering/

http://www.eaw.com/products/DSA/

http://www.audiosystems.ch/live/jbl/...r_englisch.pdf