I can't find any measurements for the Three+. I
found some for the TritonCinema Three, but I don't know how similar the tuning is between that and the plus. Now that I look on it, I'm not confident in the sound quality, given the measurements of +1 / -4 dB from 200 - 10,000 Hz.
I'm sure OP's not interested, but I just found a
killer deal on the JBL Studio 580. If
@Andrein were willing to save money on the towers and add a Hsu sub, I'm sure that would get him the sound quality he's after.