4 Ohm speakers require higher current out of the amp. All amps can handle 4 Ohm loads provided they are not asked to drive too hard for too long.

If you're sitting 8 to 10 feet away from your 80s, you won't need more than 1 Watt to achieve 85+ dB. That leaves you plenty of power with this Yammy for the majority of material out there.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated