Low Freq Response graph

[MS2112]

Could someone tell me why the response graph does not go more down to zero past the LF cutoff freq? My graphs show the LF response dropping right where it should past the F3 but then the graph jumps back up. It's similar to what the manual shows but does not follow the other freq response graphs I've seen on the low end side - which heads to zero db.
Here is an example on this page of the manual:
https://www.daytonaudio.com/OmniMicV4/hs117.htm
Here is a graphic of a 10" cabinet with an F3 of 60 and a HP filter set on the dbx driverack at around 80 and the graphs seem to be OK until it jumps back up at 20 Hz. Maybe I didn't have the volume up enough or room acoustics?

[Paul O]

room acoustics?

Yes. That is the elephant in the room, there is no separating the effects of the room from the response of the speakers at low frequencies, so if you want to know the response of your speakers alone you need to get them outside and well away from structures to do measurements.

[Chris Roemer]

Don't know why your measurement turned out that way, but you could manually edit your file. I'd set it to about 10dB @ 20Hz, 33dB @ 30.

[MS2112]

Thanks for the response (pun intended). I guess I will wait for fall as it's too hot here in Texas to measure outside. I had specifically left the volume low in hopes of minimizing the room effects but I guess that's no good.