Kurt, the BT-1 is s great size that you can position just about anywhere on your kit, but I agree with cochlea on the price point being too high, especially since it's not velocity sensitive.
The BT-1 is fully velocity sensitive. It's as sensitive as Roland mesh pads and outputs signals that facilitate the entire range of MIDI velocity values, from 0 to 127. The BT-1 has two modes of operation: Switch Mode and Sensor Mode. This is not well documented in the BT-1 manual. In fact, I don't think it is documented at all.
Confusing the matter even more is that changing modes isn't done on the BT-1, but rather on the module you have it plugged into. This means if the module isn't aware of the BT-1 and doesn't have special modes to support it, you will not be able to change modes. All is not lost though. To get full velocity sensitivity from the BT-1, you can wire a special cable or use only the peizo side of the BT-1's stereo connection. Even in Switch Mode, the BT-1 is still velocity sensitive, just to a lesser degree.
Here is how the two modes work:
In Switch Mode, two triggering components of the BT-1 come into play: switch and peizo. The switch acts as a physical gate, stopping vibrations from other instruments from causing spurious triggering of the BT-1. In the electronic drum world, this is known as cross-talk elimination.
All drum modules have cross-talk elimination in their trigger settings so why take such a sledge-hammer and non-standard approach (using a physical switch as a gate) in the BT-1? The BT-1 is designed to be mounted on the rim of another pad, on the rim of an acoustic drum, on a cymbal stand, or on a drum rack. When mounting to the rim of a pad or drum, every time you strike that instrument, the BT-1 will trigger as well. Clearly, this is unacceptable. Thus, Roland rightly created a mode so this doesn't happen.
In Switch Mode, as long as the switch inside the BT-1 never closes (meaning as long as you don't physically hit the BT-1), the BT-1 will never trigger. When you hit the BT-1, it takes a certain amount of force to close the switch so that the peizo is read. The result is you don't get quite a full range of velocity sensitivity. Soft strokes do not trigger. Only medium and harder strokes trigger. This is intentional design to eliminate the massive cross-talk and spurious triggering that would otherwise occur when the BT-1 is mounted to the rim of another instrument.
In Sensor Mode, only one triggering component of the BT-1 comes into play: the peizo. The switch is removed from the equation. Thus, the BT-1 becomes fully sensitive to soft, medium, and hard strokes, generating the entire range of signals necessary for full MIDI velocity sensitivity. You use this mode when mounting the BT-1 on a cymbal stand or drum rack.
Roland modules TD-25, TD-30, and TD-50 fully support the BT-1 and allow changing modes within the module. If you're using a different module than any of these, within your module, you may be able to choose which side of the BT-1's stereo connection you use for triggering. Failing that, you must wire a custom cable to present the peizo side of the BT-1 as your module needs to see it.
Unless you use a module that fully supports the BT-1, you will not get the different modes, because the intelligence for the modes is in the module, not in the BT-1. When using any other module with the BT-1, you will only get the Sensor Mode.
I have multiple BT-1 units and use them in Sensor Mode to achieve full velocity sensitivity.
Edited by TDM, 13 May 2017 - 07:56 PM.