No one actually knows how to lculate what speaker cable they need

Looks like you have altered your exell sheet. Your original spreadsheet had 3 participants your game, you have deleted Willson and now only have conradnash & keppertup on the latest version. It looks like the satisfaction level has dropped a half point too, from 9 to 8.5. You also removed keppertop's cost for the project. What's up with that?

https://imgur.com/a/dPO2o1p

Mr. stevecham

Your post is way off the subject and your attitude is rude. But I'll clear a few facts about your Manley Neo 250 with your speakers. https://www.manley.com/hifi/n250/

At a DF of 14.8 / 17.2 (output resistance = 0.5 Ohms) and a 4 Ohms load @ 218W, 1/8 or 12.5% of that power is dropping on the amp's and 7/8 on the speaker. So you are wasting 27W of the 218W. This is way the cable in your case has no significance. I really would care, if I would you, in such case about the DF.

At the time tube amplification first introduced, the amps had very moderate power: 10W-20W. At that time the DF was the same and it was not a problem. Some designs looked into tube as "what was missing is more power", made it to deliver a 250W but over looked all other aspects.

Your speakers demand way more than 1W. They are very demanding on impedance and low efficiency. So why would you bring up the 218W power, if you think you need only 1W? It is true that as close as you get to 0W, all problems are gone!

The spec. defines 1.5% THD (it's a lot!) and I can't hear it because I'm 10,000 miles away. But anything above 0.2% is audible. 1.5% is a bad figure for today amps.

b4icu

"But anything above 0.2% is audible. 1.5% is a bad figure for today amps."

,As true as it may be, don’t forget that people tend to like some sound so that particular distortion, as presented in numbers, may actually be beneficial and preferred by a given owner. It may not be exactly what came into the amplifier, but may be what makes an owner enjoy more. In 2018, it may be possible to make it closer to perfection, but that perfection may not be pleasant for someone. In some way like putting sugar in the lemonade or some spice in the dish recipe. Others may not like it, but who are they to say anything.