12" alnico-magnet guitar speaker. The Ruby is an alnico-magnet guitar speaker that’s purpose-built to create vintage tones – and at 35 W power handling it’s ideal for use with mid-powered amps and combos. Bringing the instantly familiar Celestion alnico vibe with its glorious dampened attack; the Ruby oozes a richly musical vintage warmth with mellow highs and a smooth sophisticated midrange.