4 or 8 ohm connection for a 6 ohm speaker?

It makes sense to try the lower tap first, but there definitely have been cases of particular combinations of amp and speaker where the tap a little over the nominal impedance sounds better.  Of course, if you ever look at some measurements, nominal impedance can be a pretty fuzzy term.

Roger Modjeski ( music reference ) advocates light loading but also listening. Clipping is bad, so listen for that also. I light load my Vandersteen TreoCT ( an engineered easy load at 6 ohm nominal ) with the 2 ohm tap on my RM-9. Amp stays in class A longer and at the relatively low volume I listen at - sounds better.
have fun - enjoy those great speakers! And the music !

As most have said already, try the lower option first. I have a pair of speakers that average around 12 ohms during play. I tried the 8 ohm posts first and was disappointed. I the 4 ohm post and the speakers sounded much better. 

HI, 
Some tube amps behave better on 8ohm taps. As your speakers demand a little push the 4ohm tap would propably be better but you wouldn't know till you have tried.

Thanks for everyone's input! Much appreciated!

Originally I had placed the speakers on the 8 ohm taps as recommended by the person who sold the pair to me...he had a tube stereo power amp. After listening to my setup at home on my Dynaco MK 3's I was never really satisfied. Is it possible that the bass was less than satisfactory and the highs were shrill? I still enjoyed listening to the speakers though and I did try positioning them slightly differently but left it that way until now. 

Today I moved the speakers to the 4 ohm tap and listening to the same music the bass was way way more full and the highs were less shrill...is that possible? I feel that is what I heard (my hearing isn't what it used to be). I do honestly think the music is better on the 4 ohm tap and I am sure I heard distortion when on the 8 ohm tap. My audio source was from a Bluesound Node 2i playing music from Tidal. 

I feel definitely more satisfied now and nothing blew up LOL. 

Bill from Nova Scotia