IME, runing two speakers in series will not help give you clarity. The problem is that the crossover in the first speaker interacts with the crossover in the secound. Phase is negtatively effected. A parallel hook up does not have the phase issue but as others have stated you may have an impedance issue.
Of course yiou can always try it as YMMV.
Of course yiou can always try it as YMMV.