@williewonka there's doubt about using solid core cables for speakers.
Speakers by their very nature, vibrations travel through the connectors, solid stranded cable is designed for vibration free environment, such as in wall. Vibrations and enough movement can break the conductor.
If the choice is current, there are many speaker cables that have larger stranded conductors to compensate the minor variation of solid/stranded cable current carrying capacity. Seven strand cable is still not enough strands, as this is still not that flexible.