I have heard a larger Triangle speaker. Haven't heard a monitor, but they use the same components in their line. Just the larger ones use larger cabinets, more drivers, and(sometimes) larger drivers. It was quite nice with tube gear. I don't really think it would be the best match for a solid state or forward setup. The speaker stuck me as needing a full sounding amplifier/front end/cables. In the system I heard it in, it was extended, fast, and dynamic. Not at all warm, rich, or full. A different philosophy from the way speakers are built these days. The cabinets are not dead, and I am told they are that way to add to the sound. Contemporary speakers try to subdue this, and muffle that, etc. The Triangle lets these things come through. I liked them, and would probably buy them, if I was in the market, and was building the right system around them.
