When connected to an L1 Model 2 and/or L1 Model 1S powerstand. 250 watts of bass power is available. What does the three position switch do exactly. Is it a choke? Is it an EQ? Does it compare to earlier Model Classic & L1 Model 1 mechanical presets (e.g. 57 & 58)?
Hi Cap,
Cap posted
Three Position Bose B2 Switch - What are The Electrical/Frequency Characteristics Of Each Position
Bose does not publish details about the proprietary EQ profiles used in the Power Stands or ToneMatch® Presets.
When connected to an L1 Model 2 and/or L1 Model 1S powerstand. 250 watts of bass power is available. What does the three position switch do exactly. Is it a choke? Is it an EQ?
Both the L1® Model 1S and L1® Model II have proprietary system EQ settings. The system EQ applied depends on whether or not a B1 or B2 is connected to the Power Stand. If there is a B2 the position of the B2 switch determines which system EQ is applied. All the processing is done in the Power Stand.
Does it compare to earlier Model Classic & L1 Model 1 mechanical presets (e.g. 57 & 58)?
The equivalent of the Classic/Model I Presets 57 and 58 are ToneMatch® Presets in the T1®. Those are available whether you are using B1(s) or a B2. The Presets may be used independently of the setting of the B2 switch.
This is how Bose describes Presets 57 and 58.
Preset 57 is optimized for low volume music. It is. Preset 57 is for prerecorded music at low level, for DJ’s and for break music at the gig Sort of like the Fletcher-Munson (Tony Sarno calls it the “Herman Munster”) curve; bass and treble boost, just the right amount if you’re playing a 85 dB or so.
Preset 58 is optimized for higher volume music. Some of the bass is boosted and some of the upper mids are reduced to have a more natural sound at these higher volumes.
This is how Bose describes the B2 Switch settings.
The B2 bass module includes a switch allowing you to select the appropriate level of bass output for your application.
There are three settings:
| Switch Position | Application |
|---|---|
| Bass voicing designed for DJ/Music playback applications | |
| Normal | Bass 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 |
ST
Hi Cap,
I assume you are asking about the 3 position switch on the back of the B2 sub.
It doesn't do anything within the speaker itself. Instead, it tells a Model 2 Powerstand what bass level to put out:
Causes the Model 2 Powerstand to increase the subwoofer output by 3dB
Normal does not change the Model 2 Powerstand subwoofer output
- Causes the Model 2 Powerstand to reduce the subwoofer output by 3dB
The EQ between the settings stays the same. Only the amount of bass changes. (You are still limited to 250W, so on you might run in to limiting sooner.)
The 3 position switch does not work with a Model 1S Powerstand.
Seems, with two replies, we have a difference of information.
Thank you for your replies and time.
Hi RobbieD, Cap,
RobbieD posted:The 3 position switch does not work with a Model 1S Powerstand.
The 3 position switch DOES work with the L1® Model 1S Power Stand.
ST
Hi ST,
Yes you are correct. I only use my B2's with L1 Model 2's but thought I had read somewhere that the switch didn't work with the S1. But I think I was getting confused with the Model 1!
Hi RobbieD,
The B2 Bass Level Switch
is not functional with an L1® Classic or L1® Model I.
Attention L1 model I and Classic users: When using the B2 with the L1 model I or Classic systems the rear panel switch must be in the Normal position. or - switch positions will not work.
Source: B2 Switching
ST
Exactly.
The switch actually switches a couple of small resistors inside the speaker connected to pins 2 & 2- on the Speakcon (the drivers are connected to pins 1 & 1-, so no signal goes through these resistors).
The Powerstand senses what resistance value is across pins 2 & 2- and knows which position the switch is in, and literally turns the bass volume up or down accordingly.
The Powerstand senses the (different) B1 resistor in the same way to set the appropriate EQ.
Great information. Thanks to you both.