Correction circuit for dynaudio driver

[AllenB]

Two text book 2nd order butterworth filters at 2k5, this looks like a good start. With the L-pad in place your impedances should be reasonably well behaved.

It is more common to use filters with Q=0.5 as they add to flat on axis. Without measuring the actual needs of the drivers though, I think it would be pedantic to say you should change anything just now.

You'll want to play with your tweeter level and polarity for now. Do you have an equaliser? If you can manage to adjust any problems out, you can the translate your settings into crossover changes.

[jimbones]

AllenB, yes the polarity on the T121 will be revered and I plan to temporarily install a L pad on the tweeter to get the balance right then replace with resistors. I guess the BW has a Q=0.7 so you are saying go for a Q=0.5?

[AllenB]

Without some design work (measurements and so forth) it is difficult to guess what order of filter each half should have, what Q, what polarity etc. You need to start somewhere and what you have is reasonable.

So when I say go for q=0.5, that takes into account the varying impedance, the phase of the impedance (it's effect on the filter), the existing acoustic response, then when it comes to matching the two, the acoustic phase and all that led up to it. This is why I'm suggesting that it may not be helpful to get too caught up in the details this early in the process.

[Lojzek]

Hi jimbones !

Originally Posted by jimbones

I tried to attach the schematic based on input from everyone. I hope I've done it correctly. Feel free to throw darts!!

This one comes late but I'll give it a shot

If you want to get the best out of the 17W's, install each one
in a separate 15 liters sealed box in MTM configuration and you will
get clean F3=50 Hz. I suggest you build a real life x-over like the one
attached and experiment with different values of resistor R, whose
sole purpose is to attenuate tweeter sound pressure and level it out
with midwoofers. In your case, if implemented well and a bit of luck
you could get decent sounding speakers with sensitivity at about
89 dB/2,83V/1m.