I just have the left tweeter crossover to finish on my Theater Seven Pis.

Goodness Gracious!!!

These things can play loud and clean! When cranked the bass blurs my vision and the percussion is so sharp it feels like you're getting slapped in the face (but no sibilance)! Air guitar is impossible to resist! I could go on and on ... Wayne, you da man!

When using PiAlign I sometimes notice a huge difference between ideal Q and encl Q.

Ex:

Rat Shack 1197
Fs=85Hz
Qt=0.37, Qd=2.7
Vad=0.17 cuft (4.9 l)
Ideal Q=40
Encl Q=10

Eminence Kappa15LF
Fs=39Hz
Qt=0.38, Qd=2.6
Vad=5.6 cuft (159 l)
Ideal Q=19.5
Encl Q=6.6

Wayne, what's going on? Is it possible to get closer to the ideal Q or is the calculated encl Q as close as it gets? How does this affect performance?

By the way, the Kappa15LF may be the road to a poor man's Pro Four Pi (small cab JBL 2226 kick ass speaker). PiAlign gives a 25.5" x 17.5" x 12" cab with a 4.6" diam x 10" port (LDF vol=300, wood=1.5). The Kappa15LF has good Xmax (5.5mm), OK Zmax (86) and low Qms (6 so no mud motor!). The freq response looks good (no big peak at 2k) but the high Le (1.27mH) will require a zobel. Wayne, maybe you should audition a few pairs and see if you want to offer them as an official Pi product. :-)

Cheers,
Jeff

Thought I'd let ya know.

Adam

I saw Colin's K15LF freq resp graph below. He indicated that he received it from a DIY buddy at Eminence. The graph on the Em website doesn't have the peak but they both show that the sensitivity is ~95dB (where did they get 101dB for the spec sheet?!?) As Wayne points out, these graphs aren't very consistent so maybe the actual response lies somewhere in between?

I guess we'll have to trust our ears.

Good luck with the Pis. Let us know how it turns out.

Cheers,
Jeff

Wanna get some Kilomax 15's? I know of a source that can get them for not too much more than you'd pay for the Kappas....

Colin

Colin, WHERE on earth are you getting kilo's for the same price as kappas? I'd love to know...

Adam

See this thread: http://www.AudioRoundTable.com/PiSpeakers/messages/1871.html. The price he quoted me is in Canadian dollars, so that converts to approximately $143 US each. Not bad, eh?

George got them for me here in Canada (He's in Toronto and I'm in Calgary). Those are his Premium Stage Four Pi's w/Kilomax 15's in the picture above.

Colin

I can surmise that the Delta probably has a similar response to the Kappa. Wayne is using 2nd order on the woofer for that design, and I haven't heard complaints. Perhaps the peak isn't as large as I thought, and the crossover is dealing with it. I'm not really sure what would explain those peaks, either.

I was thinking of using third order or even fourth on the woofer, but changed my mind. I've been using a crossover for Kappa LFA and 2002 2-ways nearly identical to Wayne's in every respect (coincidence, I assure you... :)), except the crossover is at 1.5 kHz and it doesn't have the bypass cap on the l-pad to lift the upper frequency range. So I'm just gonna use stock parts and use my design, and add the cap as well. The design sounds pretty good, so I'm gonna ride with it. I've already got four Kappas and four of the compression drivers collecting dust.. Can't turn back now.

I'll definitly let you know how they go. Gonna start soon, hope to have the first pair at least functional in the next couple weeks. Four of these things with 500 watts each is gonna be unbelievable... >:)

Adam

I'll have to look into that... Wanna buy four Kappa 15LFA's??? :D Mint condition.