Alesis M1 Active MKII Reference Manual page 16

Speaker Installation
Monitors placed on the console's meter bridge can directly radiate
This kind of speaker placement also couples acoustic energy from the
speaker's cabinet more readily into the console's chassis. Both conditions
should be reduced by placing the speakers on their own stands acoustically
detached from, and slightly behind, the console as shown below. In this
location, the reflective path off the console's control panel is now blocked by
the meter bridge.
Moving the monitors to a position behind the meter bridge causes
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back onto the console control panel causing a strong delayed
reflection at the listening position
the bridge to block the offending reflective path
Direct Path
Random
Reflections
M1 Active Reference Manual