Good question.
I have considered all three as an upgrade for my 15 year old Triangle Titus XS speakers someday.
Triangle sound I have heard is pretty distinctive. Very fast, transparent and neutral, similar to planars. High end can tend towards being a tad hot compared to many so you need to take that into consideration when feeding them. They also are fairly efficient and easy to drive with most any amp. They tend to have simple crossover design and good coherency top to bottom.
Have not heard Ref3a but I tend to see their design versus small Triangles as having a lot of similarities.
I have considered all three as an upgrade for my 15 year old Triangle Titus XS speakers someday.
Triangle sound I have heard is pretty distinctive. Very fast, transparent and neutral, similar to planars. High end can tend towards being a tad hot compared to many so you need to take that into consideration when feeding them. They also are fairly efficient and easy to drive with most any amp. They tend to have simple crossover design and good coherency top to bottom.
Have not heard Ref3a but I tend to see their design versus small Triangles as having a lot of similarities.