Kls-9 Woofer Sustitute

I´m thinking to build kls-9 loudspeakers from original design of Noel Kenwood whith Audax drivers.. http://www.audax.com/doit/england.shtml
But i got a pair of woofer Beyma 8wooferP which propperties are similar..i suppouse.My intention is to substitute the HM210ZO for this ones
Look in Studio series,low frecuency,model 8WooferP
What about the change?Thanks.