Are you using identical amps? If so have you tried vertical bi-amping?
Bi-amp crossover recommendations
The Pass Labs XVR-1 is certainly one of the best units and is still produced and supported. We have used ours extensively in the past to help us develop our loudspeakers. Very flexible.
Marchand active crossovers are also quite good and equally flexible as the XVR-1. We have used these as well. Typically Phil can customize his standard units to better suite your speakers but you have to tell him what you need. For example, let's say your speaker passive crossovers have baffle-step compensation. Phil can add that filter as long as you tell him it's needed.
A straight up symmetrical whatever order active crossover is usually not a direct replacement for the factory passive crossover. Many loudspeaker manufacturers pride themselves in their elaborate passive crossovers which are at the core of their design. They usually incorporate several filters and possibly compensation circuits. By-passing them and going truly active may not yield the performance that is expected unless these filters are duplicated.
True active systems, when designed for or adjusted for the speaker, have many advantages. There has been much written about their virtues.
I realize you said no DSP for now. You can buy a 2-way DSP unit from Parts-Express or elsewhere for around $200. They have an amazing amount of flexibility. Not only can you set up your crossover filters but add EQ and adjust delays. These units may not have the same ultimate resolution as the more advanced units but you will get a great sense how well the setup works. You will need some measuring tools either way. You can always upgrade the DSP later.
We now, almost exclusively, use DSP for our loudspeaker development to evaluate and refine the physical loudspeaker. Good units are transparent.
Tanks for the tips. Racamuti, the amps I want to use are different. Both are restored Bedini amps. The 25/25 DE has better mids and high range, the 100/100 DE has better bass control. Arian, this is being used for speaker design development. I’m making the crossovers too so no issues that need a custom designed active crossover. This is being used to get the best performance from the two amps I’m using for development. But the Marchand custom unit might be the next step once I’m comfortable with this path. I already have access to a dsp processor. Maybe it’s not a good one because I don’t like what it does to the midrange at any setting. Or possibly because I primarily use analog sources. That means starting with analog, digitizing, manipulating, then conversion back to analog before amplification. A better Dsp may also be on the list as next steps. I will be hunting for something used I can work with. The pass sounds worth searching for.
Bryston makes one, and never heard it. :)
One thing I've learned about most audiophiles turned active-biampers is that achieving the same level of driver to driver integration a speaker maker achieves with passive components isn't a very big deal to them. DSP is overkill.
Doing active crossover's correctly is a lot of work, and DSP really helps. From adding delay to EQ'ing the final result.
Even if that isn't your goal, as noted above, DSP crossovers are cheap and can help you figure out what you want and whether you want it fairly quickly.