Has anybody tried using single solid core cables?

Solid core is all I use now. I make my own from home depot wire.

Actually last night I made some solid core 12 gauge romex power cords for my mono amps. I'm blown away at how much the sound improved. Super fast and tight, very detailed but natural, a lot more open and airy with a much better soundstage. Better bass. Everything was just so much nicer.

I already had solid core interconnects I made

I have the SA Mantra 10s. They are your speakers as monitors (one step down). Before I had the SA 505 there entry stand mount. I have always used solid core exposure wire due to having an used exposure amp. I have had great results with these solid core wires. While researching newer cables someone on another fourm told Me his SA 505s were great behind solid core wires. This leads me to believe soild core are a good match for System Audio Speakers.

I would try the cheap wire first. If good go to a nicer pair used before you go crazy. I thought I saw 8 ft pair of exposure wire for 100 bucks. PM and I can direct you to ad. (No affiliation with seller).

So I decided today to change to stranded wire for my power cords. The solid core were way way to stiff.

However I went up a gauge. And made them a foot shorter. So they are now 10 gauge that I bought at home depot (14 feet for $25!!). Copper is copper.

The sound is better, more natural, and better imaging and depth, clarity. Basically everything rounded up a notch.

Pretty much wire thickness is king. Solid core is best but thicker gauged stranded can beat it out since it's got more conductive area. Which the 10 gauge does and sounds amazing. Another reason is I think the stranded gets a better connection when screwed down, it forms into the clamp better. And also the cord can bend and it's not tweaking and sits better in the outlets.

If you want to see how good some cheap solid core cable can be, try the new DNM Resolution, which is 1.30mm width, and has a fixed spacer for consistent distance between each leg.

As Nonoise said earlier, try wiring the solid core cable direct (especially speaker cables) because the connectors often really color the sound.

I've listened to single strands of every gauge there is. Use 22 gauge solid core for speakers and use 26 gauge solid core cable for interconnects. Any smaller for interconnect and the frequency response shifts upwards with not enough weight. Same thing for 22 gauge for speaker cable, 24 gauge is to small. I can guarantee with absolute certainty this is so. Larger single strands do not transmit full frequency bandwidt. In the early 80's an English company exported these very same gauges laid side by side like 300ohm antenna cable and charged a lot for these. Try these two gauges and tell me how much you liked it.