Sobrang mag init ang Marantz receiver, even in 8 ohms, what more kung 4 ohms (tapos 86db sensitivity pa, whew), grabe sobrang hirap i-drive nyan... unless you are using flagship Marantz or any Solid/Power Amplifier that can handle 4 ohms.
Most of the available consumer receivers are rated at 8 ohms, it can drive 6 to 16 ohms without any problems.
Driving 4 ohms is another story; at any given voltage drive level, a 4 ohm speaker will draw twice as much
current as will an 8 ohm speaker.
Sure it will produce louder sound if you use 4 ohm, but can your receiver or amplifier handle it? Most likely you will fry your receiver or amp.
Good thing may mga build-in auto off/protection mode pag hirap ang amp/receiver or pag may ground/short circuits para di masira.
Get a more power amp or change speaker