RT 800 6.5" drivers

I have an RT 800 speaker with a bad 6.5" lower speaker. I bought an MW 1707 from eBay because the description said replacement for RT 800. When I installed it I noticed the old 1 was marked as MW 1703. The guy I bought the new speaker from says it is same speaker just magnetically shielded. I thought RT 800 was already shielded.
My question is does anyone know if I should use the MW 1707 or find a MW 1703.