PackLite® power amplifier Model A1: Difference between revisions

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== General Questions and Answers ==

[http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/6121039062?r=2531054162#2531054162 originally posted by Kyle-at-Bose in response to questions from Oldghm] October 20, 2005

Note - all references to the system or the L1® are to the {{Classic}}.

In keeping with the premise that musicians should worry less about the gear, the system was designed to be smart about bass management. We did not want you the musician to be tasked with having to re-EQ the system depending on how much bass you decided to use. So, whether you go from zero B1s to 1 B1, to 2 B1, to 4 B1s, the system is making changes to the crossover and level to compensate the fact that you have added (or taken away) bass modules.

We did this so that the system maintains a spectral balance as best as possible so that you didn't have to manage the difference yourself. Of course with zero B1s we are not able to maintain a the wide band down to 40 Hz. The L1 does it's best down to 110 Hz. By adding B1s however the system simply shifts the crossover to 180 Hz, applies active EQ to the B1s and will attentuate the output depending on how many B1s you decide to use. As you add amplification and loudspeakers we gain more overall output in the bass frequencies. To maintain that spectral balance, we simple reduce the signal going out to the B1s (or PackLite amplifier) so that you don't need to fuss with the remote tone controls or have special presets for how many B1s (yikes!). The same tone that you found with presets and tone control adjustments with lower levels (less B1s) is now available at higher levels in those regions (more B1s).

This however is not to say that the L1 will get louder. Bass-heavy instruments like bass guitar and kick drum had a good tone at lower levels with, let's say, a single B1. Unfortunately, these players have probably found that if they needed more punch in larger rooms that a single B1 only went so far and that the L1 continued to get louder. Two B1s give you the ability to substantially get louder in the bass region- more headroom with two B1s. In expansion, 4 B1s give bass players even more headroom to play. (I believe 4 B1s will satisfy most bass players in a variety of larger venues, we've tried 8 B1s and it just seems way too much)

Said another way: As soon as you plug in a PackLite and two B1s, you will not feel a difference in sound. It was designed to perform like this! What you will find is that you NOW have the ability to change your tone. Go ahead, grab the remote tone knobs, change the preset if you want- you now can tailor your bass-heavy instruments in a way that was not so audible before with less B1s.

Originally posted by Oldghm:

:I have never claimed to have a full and complete understanding of the bass thing, so I've been doing some reading from a while back and ran across something from Hilmar that might help me understand how and why you can go from 1 B1 to 4 B1's and not hear a major difference from a vocal or acoustic guitar that really just goes down to 80hz or so.

Yes, that's correct. Fundamental frequencies of those instruments are not present below 80Hz. That is why you'll find 80Hz high-pass switches on so many mixers and microphones- it allows you to trash those unwanted frequencies. In a performance enviornment it halts the pickup of unwanted bass frequencies (instruments, HVAC units, crowd rumble) from bleeding into your mics.

Oldghm:

:Hilmar mentioned the crossover being "smart". It changes as more B1's are added.

That's right. The crossover critical frequency remains the same with one or more B1s added (or use of the Bass-Line OUT connector)- 180 Hz. The other end of the intellegence comes from knowing if you have 0, 1, 2, or 4 B1s connected and attenuating the signal where appropriate to compensate.

Oldghm:

:Please correct me if I'm wrong, but, can we assume that the crossover drops, lower and lower, as B1's are added? Thus as you add B1's less and less of the acoustic guitar bottom end is actually going to the B1's.

No, all bottom end (below 180Hz) is being routed to B1s always. The level out to bass modules will drop but only to balance the fact that more acoustic output is being gained by adding bass modules. By increasing the MASTER you'll see that all of that power is available to you, just in a balanced fashion.

Oldhm:

:Is it possible that with 4 or more B1's we actually go backwards to the point that nearly all of the acoustic guitar is in the L1? Almost as if we didn't have a B1 attached.

Never. Never!

Oldghm:

:What is the crossover when using the PS1 / L1 with 2B1's and the PackLite with 2 B1's, for a total of 4 B1's?

The crossover point is 180Hz ({{Classic}})

Oldghm:

:Is there any way to trick the "smart" crossover, and still get good results from the B1's?

There is no way to change the crossover frequency point of the system.

Oldghm:

:Is the L1 less, just as, or more, efficient at dispersing those frequencies between 110 hz and 180 hz?

Hilmar can speak to dispersion patterns better than I can but it's my understanding that 110-180 Hz doesn't do a great job at being a cylindrical wavefront anyway. Considering that it's also in a range that's not perceptibly directional (bass), it was decided to route that down to the B1 that does a much better job reproducing those frequencies. As a listener, we have a hard time hearing where that range is coming from so to the B1 on the floor it goes.

For more see [http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/6121039062?r=2531054162#2531054162 the original discussion]

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[[Category:A1 PackLite®]]

[[Category:Bass]]

@@ Line 42: / Line 42: @@
 {{:PS1 Powerstand/Bass Line Out}}
+== General Questions and Answers ==
+[http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/6121039062?r=2531054162#2531054162 originally posted by Kyle-at-Bose in response to questions from Oldghm] October 20, 2005
+Note - all references to the system or the L1® are to the {{Classic}}.
+In keeping with the premise that musicians should worry less about the gear, the system was designed to be smart about bass management. We did not want you the musician to be tasked with having to re-EQ the system depending on how much bass you decided to use. So, whether you go from zero B1s to 1 B1, to 2 B1, to 4 B1s, the system is making changes to the crossover and level to compensate the fact that you have added (or taken away) bass modules.
+We did this so that the system maintains a spectral balance as best as possible so that you didn't have to manage the difference yourself. Of course with zero B1s we are not able to maintain a the wide band down to 40 Hz. The L1 does it's best down to 110 Hz. By adding B1s however the system simply shifts the crossover to 180 Hz, applies active EQ to the B1s and will attentuate the output depending on how many B1s you decide to use. As you add amplification and loudspeakers we gain more overall output in the bass frequencies. To maintain that spectral balance, we simple reduce the signal going out to the B1s (or PackLite amplifier) so that you don't need to fuss with the remote tone controls or have special presets for how many B1s (yikes!). The same tone that you found with presets and tone control adjustments with lower levels (less B1s) is now available at higher levels in those regions (more B1s).
+This however is not to say that the L1 will get louder. Bass-heavy instruments like bass guitar and kick drum had a good tone at lower levels with, let's say, a single B1. Unfortunately, these players have probably found that if they needed more punch in larger rooms that a single B1 only went so far and that the L1 continued to get louder. Two B1s give you the ability to substantially get louder in the bass region- more headroom with two B1s. In expansion, 4 B1s give bass players even more headroom to play. (I believe 4 B1s will satisfy most bass players in a variety of larger venues, we've tried 8 B1s and it just seems way too much)
+Said another way: As soon as you plug in a PackLite and two B1s, you will not feel a difference in sound. It was designed to perform like this! What you will find is that you NOW have the ability to change your tone. Go ahead, grab the remote tone knobs, change the preset if you want- you now can tailor your bass-heavy instruments in a way that was not so audible before with less B1s.
+Originally posted by Oldghm:
+:I have never claimed to have a full and complete understanding of the bass thing, so I've been doing some reading from a while back and ran across something from Hilmar that might help me understand how and why you can go from 1 B1 to 4 B1's and not hear a major difference from a vocal or acoustic guitar that really just goes down to 80hz or so.
+Yes, that's correct. Fundamental frequencies of those instruments are not present below 80Hz. That is why you'll find 80Hz high-pass switches on so many mixers and microphones- it allows you to trash those unwanted frequencies. In a performance enviornment it halts the pickup of unwanted bass frequencies (instruments, HVAC units, crowd rumble) from bleeding into your mics.
+Oldghm:
+:Hilmar mentioned the crossover being "smart". It changes as more B1's are added.
+That's right. The crossover critical frequency remains the same with one or more B1s added (or use of the Bass-Line OUT connector)- 180 Hz. The other end of the intellegence comes from knowing if you have 0, 1, 2, or 4 B1s connected and attenuating the signal where appropriate to compensate.
+Oldghm:
+:Please correct me if I'm wrong, but, can we assume that the crossover drops, lower and lower, as B1's are added? Thus as you add B1's less and less of the acoustic guitar bottom end is actually going to the B1's.
+No, all bottom end (below 180Hz) is being routed to B1s always. The level out to bass modules will drop but only to balance the fact that more acoustic output is being gained by adding bass modules. By increasing the MASTER you'll see that all of that power is available to you, just in a balanced fashion.
+Oldhm:
+:Is it possible that with 4 or more B1's we actually go backwards to the point that nearly all of the acoustic guitar is in the L1? Almost as if we didn't have a B1 attached.
+Never. Never!
+Oldghm:
+:What is the crossover when using the PS1 / L1 with 2B1's and the PackLite with 2 B1's, for a total of 4 B1's?
+The crossover point is 180Hz  ({{Classic}})
+Oldghm:
+:Is there any way to trick the "smart" crossover, and still get good results from the B1's?
+There is no way to change the crossover frequency point of the system.
+Oldghm:
+:Is the L1 less, just as, or more, efficient at dispersing those frequencies between 110 hz and 180 hz?
+Hilmar can speak to dispersion patterns better than I can but it's my understanding that 110-180 Hz doesn't do a great job at being a cylindrical wavefront anyway. Considering that it's also in a range that's not perceptibly directional (bass), it was decided to route that down to the B1 that does a much better job reproducing those frequencies. As a listener, we have a hard time hearing where that range is coming from so to the B1 on the floor it goes.
+For more see [http://bose.infopop.cc/eve/forums/a/tpc/f/3976055944/m/6121039062?r=2531054162#2531054162 the original discussion]
+----
 [[Category:A1 PackLite®]]
 [[Category:Bass]]