Whenever I have heard Triangles I've found their sound to have perceptably flat upper frequency responses. Not overly so, and in fact, this "flat" or "nuetral" presentation is the particular sound that I personally gravitate torwards. (not always though, its just as much fun coming from the other direction too)
One more thing Gary, if your room has a lot of acoustically absorptave materials, especially on the walls, it could be that removing a few of the absorptave items may "liven" up the sound.
The soft dome tweeters on a pair of Soliloquys sounded dead and lifeless until I had well over 250 hours on them. I left it on 24/7 for weeks. In your case (tubes) it may be time to take advantage of that liberal return policy at Best Buy!
One more thing Gary, if your room has a lot of acoustically absorptave materials, especially on the walls, it could be that removing a few of the absorptave items may "liven" up the sound.
The soft dome tweeters on a pair of Soliloquys sounded dead and lifeless until I had well over 250 hours on them. I left it on 24/7 for weeks. In your case (tubes) it may be time to take advantage of that liberal return policy at Best Buy!