Is the B2 Bass Module Compatible with the L1® Classic or Model I

From Bose Portable PA Encyclopedia FAQ & Wiki
Jump to: navigation, search

B2 Bass ModuleThis information is applicable to the B2 Bass Module
Classic This information is applicable to the L1® Classic

Here is the official answer from Bose[1]

Question: Is the L1® Model I and Classic compatible with the B2 Bass Module?

Answer: Yes. When using the B2 with the L1® Model I or L1 Classic systems, please note that the rear panel switch must be in the “Normal” position. If selected to the + or - switch positions, it will not work, resulting in muted audio.


Unofficial FAQ Extension:

It says that it will only work in the Normal setting

If you have a Classic, you will get sound in all three settings, but only Normal is supported. The other two do not convey any value. more details ...

What does the B2 Bass Level Switch Do?

B2RearPanel.png

The B2 bass module includes a switch allowing you to select the appropriate level of bass output for your application (Model 1S and Model II owners only).

There are three settings:

Switch PositionApplication
+Bass voicing designed for DJ/Music playback applications
NormalBass voicing ideal for bass guitar or live sound application when mic'ing a kick drum
-Bass voicing which is perfect for acoustic guitar and vocal


Note: the B2 Bass Level Switch does not change the functioning of the B2. It triggers switching at the Power Stand to which it is attached, if that Power Stand is a Model 1S or Model II with firmware version 1.4 or later.

Why doesn't the B2 Bass Level Switch work with the Classic / Model I?

The Classic/Model I is capable of recognizing four distinct scenarios based on what is connected to it:

ScenarioB1sNotes
A No B1 Nothing is connected to the Bass Module Output
B One B1This is detected at the Bass Module Output
C Two B1sThis is detected at the Bass Module Output
D Four B1s
using an PackLite® power amplifier Model A1
This requires a combination of triggers (two B1s connected to the Bass Module Output AND something connected to the Base Line Out.

The Classic / Model I doesn't have a pre-programmed bass setting for EQ and level that directly matches the B2 Bass Level Switch in the + position. You get similar outcomes using the R1 Remote, but this is nothing built-in to the Classic / Model I that can do that for you automatically, so it cannot respond to a change in the B2 Bass Level Switch.

What Happens to the Cylindrical Radiator®
On the Classic/Model I only

When you connect anything to the Bass Module out (powered output) the system Crossover for the Cylindrical Radiator®s is 180 Hz. That is:

  • 40-180 Hz Bandpass (that is: NO B1 EQ) [2]


What the B2 Switch Does (Model 1S and Model II only)

The Model 1S and Model II (with firmware version 1.4 or greater) have EQ settings (similar to Presets) that affect the Power Stand Bass Module Out and the Bass Line Out. With the previous models the only way to activate different EQ settings was by changing the number of B1 connected to the Base Module Out.

The B2 Bass Level Switch allows you to swap out different EQ settings without having to add or remove B1s.

History

Before the release of the L1® Model 1S, only the Classic/Model I had switchable ToneMatch® Presets. The Compact has a built-in Preset for vocal microphones, but you cannot turn that off or change to a different Preset. The Compact also has a built-in Preset for Acoustic Guitar. You can turn that off, but you cannot change the Preset, nor can you change to a different Preset.

Similar to Presets the Classic / Model I and Model II all had different EQ settings built-in to support the B1s. Note: You could only change how the EQ settings were being applied by changing the number of B1s attached[3].

On the Classic / Model I, there are built-in Presets, but you have to use the Preset selector on the Power Stand to access these. There is no update to allow the B2 Bass Level Switch to change bass EQ settings (or Presets) on the Classic / Model I.

You get sound even though it says it will mute

Use the Normal setting

On the L1® Classic, you may get sound regardless of the position of the B2 Bass Level Switch. Leave the switch setting at Normal.

- (minus) position not recommended

Using the B2 Bass Level Switch in the - (minus) position puts the Classic/Model I into diagnostic mode:

  • No Bose B1 EQ optimization
  • No low pass filtering
  • No system limiter or speaker protection.

This may not cause any harm, but there is no reason to do it.

Operating with the B2 Bass Level Switch in the - (minus) position is NOT recommended.

+ (plus) position not recommended
Model I

Using the B2 Bass Level Switch in the + (plus) position this puts the system into diagnostic mode:

  • No Bose B1 EQ optimization
  • No low pass filtering
  • No system limiter or speaker protection.

This may not cause any harm, but there is no reason to do it.

Operating with the B2 Bass Level Switch in the + (plus) position is NOT recommended.


L1® Classic
  • The + (plus) setting will sound similar to the Normal setting. It won't be exactly the same, but close.
  • Using the B2 Bass Level Switch in the + (plus) position AND you run anything from the Bass Line Out, this puts the system into diagnostic mode:
  • No Bose B1 EQ optimization
  • No low pass filtering
  • No system limiter or speaker protection.

This may not cause any harm, but there is no reason to do it.


Operating with the B2 Bass Level Switch in the + (plus) position with something attached to the Bass Line Out is NOT recommended.

So is the B2 Compatible with the Classic / Model I?

Yes. However the B2 Bass Level Switch cannot change the EQ settings or Presets on the Classic / Model I.

You can tailor the sound of the B2 by using the Presets in the Power Stand and by using the R1 Remote Tone Controls.



  1. Bose official FAQs Model 1S FAQs page 6
  2. Hilmar-at-Bose intelligent crossover
    A) When there are no bass sources attached, lower the crossover and try to get as much bass out of the L1 as is reasonably feasible (110 Hz) in this case
    B) If there are bass sources bring the crossover up to 180 Hz (where the L1 starts to get really efficient) AND adjust the bass gain so that the overall spectral balance is maintained no matter how many bass sources are attached.
  3. Bass Line Out