@TomD62 fantastic work! I've been kicking around building a set just like this, so I'm very invested in your feedback. What genres do you typically listen to? It appears your related equipment is all top shelf stuff. Do you find a significant difference in the bass with SS over EL34? How is the bass compared to your Forte IV's? I've never experienced open baffle bass but hear people comment on it quite often. What is your current opinion? I'm curious to learn how placement effects bass, soundstage and imaging. Keep us up to date on your impressions as you dial them in.
Like you I had never heard open baffles myself but wanted to give them a try. After deciding against the Caladans the DIY route made the most sense. I will try to answer your questions as best I can with my listening experience so far.
Bass: SS versus EL34. In my room there appears to be lower bass response with the Krell versus the ST-70. This is also true with the Forte IV's. I have not yet installed the bass wings on the OB's but will after getting some more listening time with them off.
Overall opinion: So far I am very impressed with the soundstage, imaging, and quality of sound. I recently installed some NOS 6SL7GT tubes in my preamplifier and noticed an improvement right away. The noise floor was much lower. I have heard this expression used before by reviewers and now have heard it for myself, but the space between the instruments is much improved. These last two improvements were results of the new preamplifier tubes.
I listen to a variety of music from the last 60 years with the exception of modern country music. The other day I streamed Eva Cassidy Nightbird, which is a live recording. Was blown away, but that shouldn't be a surprise as she had a fantastic voice. Other recent listens included Depeche Mode (Violator), Alan Parsons Project (Eye in the Sky), Roy Buchanan (When a guitar plays the blues), Black Sabbath (Sabotage),... as examples. I do like having the L pad to adjust the tweeter; I believe the latest iteration of this ABX design does not have one.
Currently the placement of the OB's are 10 feet apart and 2 feet from the wall, which is much less that most recommend. I think they sound great but had tried them 3 feet off the wall with no difference. I will need to get some longer speaker cables before I can increase any spacing distances. Currently enjoying them as they are and will update when changes are made.
