Therer has always been an argument about the importance of damping ratio. With your use of L-pads and series resistors you must feel there hasn't been any negative impact on sound quality? At any rate, this may not be an important factor with HF drivers.I am not familiar with your design, but if it were my own, I'd be using two 8 ohm woofers in parallel which is then a 4 ohm load and up to 6dB more efficient than the single 8 ohm driver - basically, the amp does not have to work as hard to achieve the same SPL. Because you are going active, each band is managed independently, so you can run 4 and 8 ohm loads without incident. There should be trims on the HP to allow you pull down the level if it is too high. Drivers pending, you may need to install a passive L pad network to attenuate the HFs. In the case of my 2CH amps, they rely on this and why the HP section is just 30W. It needs the tweeter to be louder then the woofer. In my case, I made up that extra gain by wiring three XTs (they are only about 91dB, most tweeters are 94dB) and the three have given me some 8dB gain. Because I have used series resisters to bring the 1.3ohm load up to 4 ohm, I got a loss which has worked out to be pretty much right.