Tonematch Mounting Bar Reinforcement

Bose product name:

1 L1® Model II single bass package - with T1 ToneMatch™ audio engine

1 T1 ToneMatch® audio engine microphone stand bracket

Country:  USA

 

I have been using this system for 10 years now and it meets my needs very well.  My question is for the community to see if anyone has come up with a way to further reinforce and stabilize the way the Tonematch mixer rests upon the mounting bar.  I have read all the posts on the correct way to attach the mixer to the mounting bar -- that is not the issue. 

 

My experience is that, even when the mixer is attached to the mounting bar properly, it is still at risk of being knocked on the bar.  At my most recent gig, the side of my guitar bumped the mixer and knocked it off the mounting bar onto the floor (luckily, no damage ... but it did disrupt my gig).  I'm looking for some creative way to "lock" it into place so it is much less at risk of getting bumped off the mounting bar.  Thank for sharing any tips and tricks you have created to address this issue.