NO. The lower the better (ie 12 gauge is much thicker than 18). You should use at minimum 18 gauge. 12, 14 or 16 would be better.
Honestly though, Spicas aren't known for bass. I just did a testing with a pair and the imaging and mids were great but the other speakers had much better highs and bass (coincident and angstrom). If you like the sound, get a sub. A passive sub and crossover would work well and if you need more power (since spicas are not that efficient), get a powered sub with a nice crossover.
Honestly though, Spicas aren't known for bass. I just did a testing with a pair and the imaging and mids were great but the other speakers had much better highs and bass (coincident and angstrom). If you like the sound, get a sub. A passive sub and crossover would work well and if you need more power (since spicas are not that efficient), get a powered sub with a nice crossover.