Best deal on unterminated bulk silver speaker cable for budget audiophiles

Move the amps closer to the speakers.
You can buy less costly microphone cable from the pro dealers which is likely the same as was used during the recording 😁.
Skin effect also affects the audio range. Use separate insulated strands of AWG #27 or thinner. 

Try navships on e-bay.  He specializes in many different gauge silver plated copper wire, very high quality mil spec.  Used on Navy ships and NASA.  I’ve purchased a number of his products and find them excellent.  Multi strand with each strand silver plated.  Have rebuilt a few amps with his wire and to my ear compares well to pure silver wire.  I think his thickest gauge is 12, but the prices are so favorable I’ve doubled them up making a braid for speaker cables.  

He is located in Iowa and is very fast to ship.  No affiliation.

You might want to try this company,  Custom audiophile speaker cables or this place Speaker Cables Archives - Audio Art Cable

The SC-5 ePlus Cryo Treated Speaker Cable from Audio Art Cable would be the one you want 8ft for $950.00 plus what ever type of connector for an extra $50.00 to $100.00 dollars.