That crossover is not designed to be used with drivers rated for something other than 8 ohms. If you wired the woofers in series that would at least be 8 ohms, but the midrange being 4 ohms is too far off. Generic crossovers are usually a roll of the dice at best, but in this case the odds are very much against you in my opinion.
Duke
dealer/speaker designer & manufacturer
Duke
dealer/speaker designer & manufacturer