Guess How Big My Speakers Are

it is impossible that you are actually getting as much output at 20Hz as you are in the midband.

@herman In an anechoic room you’d be correct. The room however bedevils those expectations, and that’s the point of the posting. 

I'm going to stick with my initial response. I don't care what kind of room you are in, .. you are not  really getting a strong 20 Hz out of those speakers

@herman but it is, and I’ve measured it. It’s not "real." It’s not the capability of the speaker so much as the resonance of the room.

Rooms can add 20 dB or more in a node, so this is totally possible. However, it is very much range limited. :)

From my new blog entry, you can see that compression eventually must set in...

Here you can see the output at 60, 70 and 80 dB is fine, only when we get to 90 dB is the output compressed.

@herman 

I did retest using Room EQ Wizard and OmniMic.  REW measures about 5 dB lower at 20 Hz than OmniMIc.  It also shows a weird clipping at the top octaves.

While I agree 100% that you can't get loud at 20 Hz with small drivers (this is pure physics) I hope you see that my argument that rooms are complicated and we can't assume we know what's going on without measurement is worthwhile. :)

While deep the output is only 75db in the graph so could be anything. Large speakers are needed for full range at high output. Small active speakers go super deep, just not loud without compressing. 

@james633  - Absolutely right.  No way we are getting live level performances out of these.

One thing this shows too though is that if we wanted to use a sub we absolutely have to high pass these speakers or the combination would be a hot mess.