I recently got a 7.1 surround sound setup but the receiver had no hdmi in ports so basically it was a over powered DVD player. So I was looking at getting a Harman Kardon AVR-347 second hand but the ports for the speakers say "speakers 8 omes" but my speakers that I have say "rated impedance :3 omes". What does this mean for me and will it ruin my speakers if i plug them in?