Stereo / Mono / Distributed Systems: Difference between revisions

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Place the {{L1 nl}}s at least 20 feet apart to avoid undesirable [[Multiple Source Interference|multi-source interference]]. Spacing closer to 50 feet is more typical in terms of covering large audiences.

=== Bass Power Alley ===

Question:

:The Compact line array is significantly shorter than the Model I or II they could be used closer together than the 20ft mark.

Answer:

Yes, my instincts and experience tell me that this should be true -- say down to 10' -- but I haven't done a clean experiment to prove it to myself, so some caution is advised.

And I'll point out that below say 200 Hz, all the L1 systems are essentially omnidirectional and the spacing of 10, 20, or even 30' can create an audible "power alley". Once you get beyond these distances, the balloon animal has so many closely spaced bulges and creases -- even at lower frequencies -- that our ear doesn't hear them individually but rather hears the average. The [[{{PAGENAME}}#Balloon Animal|balloon animal]] turns into something more like a Japanese fan.

[http://bose.infopop.cc/eve/forums/a/tpc/f/7521050644/m/756102391?r=801102491#801102491 Source: Ken-at-Bose]

=== Delay and Mono ===

Question:

:Would a few ms delay be enough to avoid the "interference" from dual mono?<br />Do you have a value for the latency when daisy chaining Compacts?

Answer:

Pure delay does nothing to fix interference "globally" (I'll explain) but can be used "locally". In this case (L1 systems, spaced, all getting the same signal) I believe delay will turn out to be not useful.

==== Balloon Animal ====

Imagine a balloon animal as a representation of the radiating characteristics of two like sources fed the same signal. The bulges are high SPL and the creases are low SPL, caused by interference.

Say the balloon animal is a dachshund.

Point the nose at the audience.

Pure delay on one of the signals is like rotating the dog.

It doesn't change the bulges or creases (that's the global part) but does change their direction (that's the local part).

If you wanted to change the direction of "power alley" (explained above) caused by two subs on either side of a stage, because the mix engineer was getting blasted by bass, you could do it by applying delay to one of the subs.

All that does, however, is change the aiming of the howitzer to someone else.

This technique can be extremely useful in optimizing the radiation pattern of a speaker in the crossover region, and is used all the time in big-venue boxes.

[http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/900104591?r=190102491#190102491 Source: Ken-at-Bose]

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[[Category:Stereo]]

[[Category:Mono]]

@@ Line 54: / Line 54: @@
 Place the {{L1 nl}}s at least 20 feet apart to avoid undesirable [[Multiple Source Interference|multi-source interference]]. Spacing closer to 50 feet is more typical in terms of covering large audiences.
+=== Bass Power Alley ===
+Question:
+:The Compact line array is significantly shorter than the Model I or II they could be used closer together than the 20ft mark.
+Answer:
+Yes, my instincts and experience tell me that this should be true -- say down to 10' -- but I haven't done a clean experiment to prove it to myself, so some caution is advised.
+And I'll point out that below say 200 Hz, all the L1 systems are essentially omnidirectional and the spacing of 10, 20, or even 30' can create an audible "power alley". Once you get beyond these distances, the balloon animal has so many closely spaced bulges and creases -- even at lower frequencies -- that our ear doesn't hear them individually but rather hears the average. The [[{{PAGENAME}}#Balloon Animal|balloon animal]] turns into something more like a Japanese fan.
+[http://bose.infopop.cc/eve/forums/a/tpc/f/7521050644/m/756102391?r=801102491#801102491 Source: Ken-at-Bose]
+=== Delay and Mono ===
+Question:
+:Would a few ms delay be enough to avoid the "interference" from dual mono?<br />Do you have a value for the latency when daisy chaining Compacts?
+Answer:
+Pure delay does nothing to fix interference "globally" (I'll explain) but can be used "locally". In this case (L1 systems, spaced, all getting the same signal) I believe delay will turn out to be not useful.
+==== Balloon Animal ====
+Imagine a balloon animal as a representation of the radiating characteristics of two like sources fed the same signal. The bulges are high SPL and the creases are low SPL, caused by interference.
+Say the balloon animal is a dachshund.
+Point the nose at the audience.
+Pure delay on one of the signals is like rotating the dog.
+It doesn't change the bulges or creases (that's the global part) but does change their direction (that's the local part).
+If you wanted to change the direction of "power alley" (explained above) caused by two subs on either side of a stage, because the mix engineer was getting blasted by bass, you could do it by applying delay to one of the subs.
+All that does, however, is change the aiming of the howitzer to someone else.
+This technique can be extremely useful in optimizing the radiation pattern of a speaker in the crossover region, and is used all the time in big-venue boxes.
+[http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/900104591?r=190102491#190102491 Source: Ken-at-Bose]
 ----
 [[Category:Stereo]]
 [[Category:Mono]]