1.I am using the JM lab SW 700 sub. The sub has both line in (two RCAs) and sub in (one RCA for 5.1). My 7300 has pre-out for 7.1
2. Normally, I connect the sub-woofer out from receiver to the 5.1 of the sub. Unlike my previous Denon who let you control the sub for all stereo and surround mode, my new Marantz 7300 by default only allow the sub in Dolby digital and DTS 5.1 that's why I can not have the sub operated during stereo and stereo sourse direct and other format.
3. Yesterday, I try both sub-woofer out ------> 5.1 in put and two L & R pre-out -------> RCA L & R in put to the sub and I have sub operated in all mode.
4. I would like to put some questions here:
4.1 When in 5.1, what connection will be forced into operation? 5.1 in put or RCA in put? and does it effect to quality of LFE channel if the line in put is operated?
4.2. Is there any harm to the sub if both in put are operated. Eg in Dolby Digital or DTS, the receiver will out put the signal by both Sub-woofer out and line out R & L channel.