I am new to these sub woofers. My mains are 10 inch Sansui 2500X's and think I could use some more Lo Fi as the old ears have given up on the Hi Fi !

My old mains are 8 ohm driven by a Sansui 9090db rated at 125 watts/ch RMS at 8 ohms. I said they were old. Most of the sub woofers I see are 4 ohms. I see some subs have two coils and allow both mains to be hooked up to the sub woofer. Is this a problem?

Thanks

Charlie