Behringer CX2310 Mismatched slopes. Other options?

Howdy all. Been building up a system in my studio for mixing, trying to keep costs and latency down if possible. It consists of some Kali LP6v2 and a DIY 12" woofer/bass module/speaker stands that the monitors sit on. It all sounds quite lovely and provides a great budget mixing platform on a budget, at least when it's all functioning properly. I've tried various unbalanced DSP solutions but didn't care for them, mostly input voltage limitations. I had a behringer CX2310 lying around that seemed like a perfect fit until I hooked it up.

It sounded fine, but kind of off. I went ahead and measured the speakers and the slopes looked off. I bypassed the speakers and just measured the unit with a loop back into motu m4. Oh my, the slopes are totally different for the left and right outputs. I assume this is from age or tolarences or just being one of the behringer products that they didn't care much about. I don't see repair on this as being worth it, so I'm open to some suggestions. Just need 2 in and 4 out.

Do you think I should expect the same results from other analog crossover units? I understand it's a bit dated tech but it doesn't add any latency and they can be found cheap. Thomann appears to a few options, the minidsp is cheap but looks to not meet what I need voltage wise. The 204 looks better, but none match the might of the analog untis which look to be on average of 22dbu in.

While I'm not interested in using this behringer unit, I'd be curious to know why the slopes could be off, but still look so clean?

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