"speakers with exceptional tweeters to an excellent job of separating both the sections and individual instruments in an orchestra"
I would call this higher resolution not "openess". High frequency extension can give more detail. Metal dome tweeters like B&W will typically be more detailed than a soft dome (as compared in my room with various speakers like Ellis 1801 and Ascend Acoustics CBM-170). Presentation will be more "airy". Cymbals will shimmer more for example.
To gain what I quoted you as saying above I think these are important:
1) Reduce cabinet vibrations as much as possible. A smaller cabinet will "talk" less. Also a more narrow front baffle will reduce reflections which muck up the sound.
2) Use a light weight driver material. Electrostatics, kevlar cones, and paper like A-P Virgo II's can react quicker to an input signal. Polypropylene eats detail due to heavy weight, and undamped ringing resonances in the driver itself.
3) Consistent off-axis dispersion. Stereophile measures off axis frequency response and lines which are fairly parallel to each other but decreasing in amplitute represent stable off axis response. This is vital to get stable, pinpoint imaging.
I would call this higher resolution not "openess". High frequency extension can give more detail. Metal dome tweeters like B&W will typically be more detailed than a soft dome (as compared in my room with various speakers like Ellis 1801 and Ascend Acoustics CBM-170). Presentation will be more "airy". Cymbals will shimmer more for example.
To gain what I quoted you as saying above I think these are important:
1) Reduce cabinet vibrations as much as possible. A smaller cabinet will "talk" less. Also a more narrow front baffle will reduce reflections which muck up the sound.
2) Use a light weight driver material. Electrostatics, kevlar cones, and paper like A-P Virgo II's can react quicker to an input signal. Polypropylene eats detail due to heavy weight, and undamped ringing resonances in the driver itself.
3) Consistent off-axis dispersion. Stereophile measures off axis frequency response and lines which are fairly parallel to each other but decreasing in amplitute represent stable off axis response. This is vital to get stable, pinpoint imaging.