Speaker cable length

Mr.  simao

Speaker cable is all about resistance.

R = (ro x L) S
When R is the cable's resistance in ohms.
ro is the material's constant conductivity figure.
L is the length in meters.
S is the cross section in mm2.

If we talk abou your system, that for some reason, is not specified, what makes or breaks the deal is your Amp's DF.
If you own a tube amp or a HT receiver, cables won't change much.
If you own a good power Amp and pre, it might have XLR (balanced) in/out. Use a balanced cable (as long as you wish, up to 500m, and place your Amp's (monoblocks) as close to the speakers (speaker cables can then be reduced to 1/2 meter!), and place your source and pre. where you like it. That's the optimum solution, if you look for one.

@b4icu. My amp is a line magnetic 518. My speakers are spatial audios M3 turbo s's. I would be doing the switch of the components off to the side purely for aesthetic purposes. I'm using a pretty narrow salamander rack and a low amplifier stand for the line magnetic, and my spatials are about 5 ft off the back wall, so I doubt the component stands are doing anything for the sound since they are way back behind the spatials. And I would definitely go with XLR, except the line magnetic only has RCA inputs.

I recently bought new speakers, new speaker cables and changed the speakers location. I now need one 5meter speaker cable and one 7 meter speaker cable. Was concerned the length and also length mismatch would be an issue. Unfounded worries, sounds great, soundstaging is terrific.
Amp=Conrad Johnson MF2250A .. speakers Magico A3 .. cables Morrow SP4.

It’s more important to keep your TT cable(s) short.

McIntosh guidance: for 18 awg: 4 ohm speakers:15 lf; 8 ohm 30 lf; 16 ohm 60 lf.

I finally made my new speaker cables (16 ohm speakers) two days ago, 16 lf each. I always keep speaker cables the same length. I needed to reach the further left side,

see 2nd photo here, system in background of ’cleaning’ photo

https://www.ebay.com/itm/133640511355

16lf gave me extra length at both ends: to leave them connected and pull my speakers forward, spin around, take the back off; and to pull the separate cabinet on the right side (with preamp and amp on it) forward, spin around.

I bought direct from Asia thru Wish, total 32lf for $215. delivered ($6.72/lf).

OFC Cat 8 S/FTP 22 ga, (8 strands equal 13 ga.) Pure Copper Spades, Pure Copper Connectors at Speakers.

My hands are a bit sore from stripping 64 strands, twisting, compressing the strands, attaching 8 spades with 2 set screws.

If your line magnetic 518 is this:  https://www.stereophile.com/content/line-magnetic-audio-lm-518ia-integrated-amplifier-specifications
Than you should not be worried about the cablelength...just keep it with low C. The nature of Tube Amps is of low to very low DF. As so, cable's resistance is insignificant.