Can I use the 12 guage Duelund tinned wire for a 25 foot run of spekaer cable

https://jeffsplace.positive-feedback.com/first-listen-duelund-600v-dca12ga-tinned-copper-tone-wire/

Yes you can use it for speaker cable and it sounds very good per my comments above. They do sound a little different.  Cotton is a tad more airy and Polycast is warmer. 

also isnt that for power cords??- I can use it for speaker wire??- thks so much-

thks- why such a price dif. between the polycast and the cotton/oil hook-up wire?

Those speakers are not the most efficient and your big SS amp with over 25 feet of cable length points to a double run of the Duelund 12 gauge.  As you know, I make and sell by Acoustic BBQ line of cables using Duelund wire. A double run will be MUCH better sounding for your rig. That’s what I use for my 20 foot runs.   Better bass foundation, greater sense of ease, improved dynamics, better fleshed out mids and bigger stage. 

You can buy the 12 gauge in Polycast on sale right now at Parts Connextion making this double run very affordable. The Polycast version also sounds wonderful.  Very full bodied with great bass and mids. The highs are sweet and never too forward or ragged. 

Ok thks- so before I order these long runs- is Duelund the best DIY to get- I have heard good things about VH Audio- If it matters I will be using it to run a MCintosh 601 mono's( 600 watts) and the Dunlavy V's speakers- just want to make the right choice before I spend the $$- thks

Double run a 16 with the 12, with light twisting.

YES! 12 guage is fine! No problem! 

Yes you can, but I would consider a double run if your Mac is high powered SS.  

Yes