Based in Bulgaria, European audio company Thrax has been active since 2009. Their ingenious and varied design approaches seen over several product lines have continued to intrigue me with their conceptual originality, innate musicality, and imaginative use of a broad spectrum of technologies. Their products range from valve (tube) amplification to digital audio and, more recently, loudspeakers . . . The range of distinctive high-end electronics has continued to expand to include a loudspeaker, the standmount Lyra, now joined by the smaller Siren ($13,600/pair), also a standmount and the subject of this Stereophile review.