Magnaryder wrote:A driver's directivity into the vertical plain is called HASS effect. Carver ribbons have no HAAS effect reflections, this is good....most of the time.
The Haas effect is a psychoacoustic principle relating to how humans perceive and localize sound events.
To localize an event, the computer between your ears pays attention to direct sound, early reflections and the reverberant field. Piecing these together tells you where the sound is coming from and how big the room is.
All Haas said is that if the direct and early reflections are within (IIRC) 15 to 30 milliseconds of each other your brain cannot distinguish between them as separate events.
In the LEDE (live end dead end) room treatment idea, early reflections from nearby walls where absorbed, and later reflections at and behind the listener were diffused. The idea was to separate the early reflections by at least 30 milliseconds AND group them together in arrival time (as nearly as if possible).
The end result being a direct sound, followed by a Haas 'kick' of early reflections (this time perceived as two separate events) followed by a reverberant field. The Haas 'kick' was supposed to trick the brain into hearing the original recording's acoustic space, instead of smearing the sound with reflections within the Haas limit. (ala Bose)
I might be picking nits, but the ribbon, being a dipole, will have a more figure 8 (front to back) dispersion pattern, and therefore less side wall reflections than a cone, which WILL lead to more accurate imaging in the sweet spot with little/no room treatment, but NEITHER type of transducer has Haas reflections. The reflections will either be within or exceed the Haas limit.