Here is an updated version of NASP the NASP II.
It uses the Peerles Nomex 164 WR 33 102 NWP AL LS 8 ohm Bass/mid. This woofer has a nice smooth mid band response and good off axis response. There is a break up mode peak centered on 4.5 kHz from 3 to 5 kHz. This basically mandates a crossover around 2 kHz.
The Tweeter is the highly cost effective Vifa BC25SG19-04. This tweeter has a flat response in its pass band to 9 kHz were a gradual HF roll off begins. The roll off becomes steep at 18 kHz. However for a small bookshelf speaker this is no bad thing, and I have made no attempt to correct this HF fall off.
Fs is 1060 Hz so I have made the tweeter to be 24 down at Fs.
The woofer is in a standard B4 ported enclosure.
The crossover