SEOS12 and AE TD12M design

Bill,
Could you say a few words on why the tweeter is not reversed on this design but is reversed on the TD15M & SEOS-15 design? The crossovers look very similar.

I'm very sensitive to tweeter polarity as my surrounds have the tweeter polarity reversed and sounded horrible with my Fusion-12 Tempests. I ended up reversing the tweeters on the surrounds (EV ELX112's) to avoid the out of phase sound, at the expense of some loss in fidelity around the crossover region on the ELX112's.

I have a pair of SEOS-15/DNA360 pulled from a pair of Cinema 88's's that didn't work out and am thinking about using them for a TD15M & SEOS-15 build to replace the L-R Tempests. But I'd need to replace the center channel Tempest crossover to match the new L-R's, hence the tweeter polarity question.

 

Does anyone have an idea of what the sensitivity of these would be?

 

Would it be possible to use this crossover with the 4 ohms version of the TD12M?
I'm assuming it can't, at least without some modifications ?

 

It really should be redesiged, not just scaled for different woofer impedance as both the impedance and the sensitivity is different for the 4 ohm version. But the following values should get you close:
change--
L3 to 1.8mH (with <0.3 ohms DC)
C3 to 24uF
R5 to 1.5 ohms
R2 to 8.2 ohms

This hasn't been built, though, so no guarantees (it will play of course, but how flat is TBD).

 

Thank you for the quick response.

 

BillWalso, I used this your design on my dna360/td12m setup. I love it, but I wanted to experiment with bumping up the treble a little bit. Would it be a simple as changing a few resistors in the high pass filter? Any recommendations on values? Also, do you use a specific software to model crossovers with? I wanted to start toying around with modeling my own.