Midrange depression in room response

[AllenB]

Mid (blue) and woofers (green) measured at 6ft outdoors.

Can I assume from this that the only surface involved in these measurements is the ground, and therefore the floor bounces are shown clearly here near 200 and 250?

 

[MtBiker]

Can I assume from this that the only surface involved in these measurements is the ground, and therefore the floor bounces are shown clearly here near 200 and 250?

Correct, the nearest walls are a good distance away.