I think you should try 4 and 8 ohm taps and hear what sounds better to your ears. There is no way that the 16 ohm tap would be the right ones to use as the B&W speakers are pretty well known to have lower difficult impedances. As the other who have answered here said you won't hurt the amp or the speakers unless you turn it up real loud and get hard clipping.
4 8 or 16 ohms.
Hi group I just purchased the Audio Research REF 750s mono amps. On the back for the speaker terminals are 3 sets of binding posts. 4 8 and 16 ohms. I will be using B&W Matrix 800 speakers. I believe they are 8 ohms but not 💯 sure. I looked in the manual but can’t find anything about ohms. Someone said to me it does not matter what ohms I connect my speakers to. He said just use the ones (ohms) that sound best. Does that seem right to do ? I don’t want to damage my speakers or amps.  BTW if it matters I will be using an Audio Research REF 6SE pre amp.Â