El Pipo: Any fresh new ideas?

[WithTarragon]

I was intrigued by the El Pipo. In spite of all the inherent disadvantages of the basic configuration (resonances etc) it actually measured surprisingly well. It is visually appealing also.

Has anyone gone the next step and tried different drivers (the originals are no longer stocked and was not clear what the T/S parameters were)? My own interest would be a scaled down pair to supplement a pair Martin-Logans (they simply do not dig very deep) for listening to music.

As far as I can tell the important parameters are probably a largish Xmax and a lowish Fs. I am also assuming that the stuffing is severely impacting the cabinet's efficiency. Has anyone been playing with these, does Hornresp capture these very well?

Part of the fascination is the ease with which these can be built (and experimented on). If I put my thinking cap on, there may be a clever way to easily introduce a taper and give a bit of loading to the driver. All in good time.

Intrigued,
-Tom