Hi, all.

It's my first posting. I have made a full range loudspeaker using Alpair 12.2P with Pensil design.
The next one is Thiel 2 2, which is my reference.

First graph shows frequency/dB at 1m distance, on axis, measured with Smartphone application. It shows a peak btw 4-8Khz.

The second graph was measured at 3m distance, 30 degree off axis, my listening point. The peak was smoothed.

I thought the peak might be baffle step response. At first, I thought BSC filter would be necessary. However, it has been smoothed at my listening point, thus, I did not opt the BSC filter.

The sound. It's very transparent, slightly bright.

Bass extension is not quite satisfactory. I also have built a FR following WIBAQ design, using 8" driver, whose bass extension is more superb. I think the bass extends to about 70Hz, not so deep.

Soundstage is very wide, not so deep. It does not make multiple layers comparing to Thiel 22.

It works well with my Firstwatt J2, and Berning EA230. But does not works well with my SET, using 205D tubes. I think it is some power-hungry.

IMO, Alpair 12.2P is a good unit. And Pensil design is also nice. Because the sound is very clear, it plays classical musics very well. However, if you expect very deep bass, you would be disappointed. And it lacks of high trebles, it cannot make multiple layers.