They suggest 6-16 ohm speakers.I wouldn't do it.Page 25.
[http://www.pioneerelectronics.com/pio/pe/vgn/images/portal/cit_11221/50103operating_instructions_VSX-43TX_20021231238549400.pdf]
[http://www.pioneerelectronics.com/pio/pe/vgn/images/portal/cit_11221/50103operating_instructions_VSX-43TX_20021231238549400.pdf]