to add a subwoofer or not to a full-range stereo speaker system?

[atomant]

Preliminary tests. I wanted to linearize frequencies below 40 Hz and I think I succeeded, with a different woofer and retuning of the vent.

Compare the curves in the first posting in this thread with the following one. Same conv filter applied, room with several changes, new woofers, vent retuned to 20 Hz. It still has some form of correction, but not optimal anymore:



Now, measurements at the MLP, no filter whatsoever:



I have not used the data above. Instead, I'm experimenting a method a la DIRAC to average several measurements around the MLP using pink noise and RTA, no filter:



Measurements with the filters created from that pink noise + RTA data:

 

[atomant]

2nd tentative. The first one was good but I wanted to get rid of some nodes that you can see in the last picture of my previous post.

I moved speakers and also the MLP from:



to:



and here is the result: