Mastersound Compact 845

Just purchased the above and I am loving it. Moved away from a Bryston system. Also made a change to my speakers at the same time. Had little Totem Model 1 Sigs and went with the Pioneer S-3EX speakers. The combo sounds great. I never thought there could be such a night and day type of change.

The Mastersound Compact 845 lets you attach your speaker cables to 4ohm or 8ohm posts. My Pioneer's are 88.5db at 6ohm. What would be the recommended speaker posts. I am currently using the 8ohm post and it sounds great. Am hesitant to try 4ohm in case it damages something.

Any thoughts are greatly appreciated.

audioman999 won't damage anything by attaching your speakers to the 4ohm post. You should try and see which you like better. Theoretically, you should get more control over the bass frequencies through the 4ohm tap but you should try it out and see what you think. Congrats on the new equipment.
I found with some Yamaha's that were 6ohm on my Almarro, the 4ohm sounded a little less dynamic and had less bass than with the 8ohm outputs.
But Cmalak is right, try them both and see which one sounds the best on your system.
8 ohm
Great amps. Enjoy.
Great amp. I tried bothe options (4ohm speakers). 4 ohm connection much better, much better bass control. But if bass is Ok with 8 ohm then you should stay there.
Always try both taps because you never know what you may find out is how I have always done things. If these measure anything alike the S1EX's, and they surely should in the bass region, they will play a highly capacitance load down below 4 ohms (3.6 ohms to be exact). Anyhoo, I personally need to try the 8 ohm tap myself since I assumed 4 ohms would work best knowing that even Pioneers rating is 6 ohms, though it is rated more as I say, 4-8 or so ohms. Not sure if you still listen to these speakers, but I absolutely love the S1EX and suspect the S3EX to sound wonderful also.