I looking into tri-amping my speakers. When I replace the passive parts and insert an electronic crossover are the amplifier channels hooked up directly to the speaker drivers?
Yes, at least for the woofers and midranges.
I run my tweeters directly connected to the amps also. My TacT amp implements a DSP crossover that keeps the output to the tweeters safe. This required a leap of faith during set up -- with 18 expensive Raven ribbons at stake -- but there have been no problems at all.
If you are not using a TacT amp, it would be very wise to put a safety capacitor between the tweeters and amplifier. Otherwise if the amp sends out any spurious signal (like at power up or down) or there is some DC offset the tweeters may well fry. This is particularly true with ribbon tweeters which are quite delicate.
