I may be able to help here,
Sorry about the time delay but I only joined the forum a couple of days ago...
It sounds to me like the speakers are bi-amped, which is essentially similar to a sub crossover system, splitting high and low frequencies.
When the amp was originally made it should have come with two gold-plated inserts which bridged the hi and low poles on the amp. You would normally connect the speakers to the high frequency and the links would do their job.
If you re link them and use speakers of equal resistance (normally 8ohms for sony home gear) then you will be fine, actually sony amps normally work well with anything between 16 and 6 ohms.
Hope this helps
