green mountains

GMA has a white-paper on its web site concerning time allignment and phase coherance and the relationship between the two. About half way into it, they make the point that time coherance is the condition for phase coherance-- not the other way around as mentioned above.

http://www.greenmountainaudio.com/time-and-phase-coherence/

I recently had a two-week audition of the Eos-HX monitor. The HX reportedly reduces phase shift to +/- 1 degree across a wider frequency range than with prior Eos iterations. I liked these speakers very much-- particularly good value at their $4K MSRP.

Kenjit, Eos moves lots of air through dual ports to achieve mid-bass and LF reinforcement uncharacteristic of most monitor speakers. In any reflex design there are inevitable trade-offs between LF extension and mid-bass and LF coherance. Eos does well in this regard, but its strongest suit is seamless mid to treble. Sitting in the sweet spot close to near-field listening the soundstage is deep and wide with exceptionally stable images contained inside less diffuse boundaries than one may be accustomed to in speakers exhibiting greater phase distortion. The experience takes a bit of getting used to, and falls into the catagory of "less is more."

While "coherant" in terms of phase response, they may not be the last word in resolution and expressiveness of nuances of timbre-- which should be no surprise at this price point. However I haven't heard anything in the $5K range that surpasses them, and their small sins can be forgiven as sins of omission rather than commission.

Kenjit, I didn't sense the frequency imbalance that you describe, nor was this remarked to me by any of the 30+ audio society members who heard Eos-HX at a club meet. I have also spent quality time with a friend's Calypso HDs. On low power SETs these had good tone and frequency balance as well. However, going back in time to an earlier model on display at RMAF 2010, I do recall hearing a bit of that in the GMA room. Show conditions can of course be problematic.

FWIW, I found that the 4 ohm Eos-HX relaxed considerably on the low impedance taps of my modified 75 wpc BAT tube amp.