My top tube angle is a few degrees below horizontal but every bump the speaker would vibrate and try to walk out

I mounted the speaker on the top tube just behind the headset, and the vibrations of the road made the speaker and mount make the most ANNOYING tapping sounds, even though the mount is rubber

I keep my phone in my seat bag and the speaker was mounted on my top tube

The "bottle holder" that comes with the speaker is not tight enough to keep it from rotating around, or if you mount it on the top tube like I did, keeping it from vibrating out and falling away