bipoles/dipoles for music...

I have an entire 7.2 HT system with bipolar LCR and surrounds, with
omnidirectional rear surrounds. The L-R speakers are Mirage M5si
floorstanders with identical woofers, tweeters, and ports firing both front and
rear. I originally used them for a couple years as a stereo pair and expanded it
into a surround system. I love these speakers either way. What I really like
them about bipolars and omnis in a surround system is that it provides a 360
deg. seamless soundfield. You never hear channels handing off from one
speaker to another. It's continuous like real life.

My living room 2-channel system is anchored by a pair of Mirage OMD-15s,
which are more omnidirectional, but with a 60/40 tilt towards the listener. It
won't create the etched 3D sonic hologram of mini-monitors, they create a
realistic sounding--and acting--soundstage that remains stable when you
move around the room, just as it would in a live concert. The speakers scale
very well too. Solo guitar or voice centers between the speakers with a
realistic size image. Similarly, when you play big band or full scale orchestra,
the soundstage expands accordingly. The lack of suckouts and hot spots help
create an even power response. Personally I find the timbre-correctness and
realistic soundstage make it easier to losse myself in the music than if the
primary strength is an imaging precision beyond what I can hear in most live
concerts.

Read reviews of Ohms, Mirage, MBL, and dipoles such as Magnepa, Martin
Logan, and Quad. You'll seldom see a criticism that the speakers smear the
sound or sound artificially large. Quite the contrary; most reviewers find the
soundstages thrown by omnis, bipoles and dipoles to be more involving. One
difference; the bipolars and omnis tend to be more placement friendly,
whereas the side-canceling nature of dipoles makes them more placement
sensitive. However, although the bipoles/omnis are more placement friendly,
their presentation improves considerably with thoughtful placement.

I think we need to make a distinction between soundstage and imaging.
Soundstage is the overall width, depth, and height of the stereo image thrown
by the stereo pair. I *do* like the soundstage the best from omnidirectionals
because the soundstage stays stable relative to the 2 speakers even when you
move about the room. Unlike most forward-firing speakers, it doesn't
collapse when you move outside the width of the stereo pair. You can still
hear what both speakers are doing, but it's like if you're at a live concert and
you're sitting in one of the side sections. I was just auditioning a pair of nice
forward-firing speakers a few hours ago and I noticed that when I moved to
the left of the left speaker, the left speaker was all I could really hear. Not so
with omnis and bi-polars.

Many people distinguish imaging from soundstage, being that imaging is how
separate and holographic the individual images within the soundstage pop
into sonic focus. In other words, the soundstage defines how big the
soundfield is; imaging defines the elements within it. For imaging, definitely
you get more finite images with good panels or mini-monitors properly set up
and with you listening in the sweet spot. However, omnis and bipolars image
better than most people think they would. In fact, I find that omnis image to
about the degree I hear in live concerts. In a live concerti don't really hear
everybody's presence etched in 3D space as precisely as I do when sitting in
the sweet spot focused on mini-monitors.

However, given the omni/bipolar advantages in power response, stable,
realistic and scaling soundstage, and truth of timbre, I can comfortably give
up that last bit of imaging for all the other advantages I hear.

If you have a forward-firing pair of speakers and un uninterrupted home life
where you can consistently sit in the sweet spot, you might as well enjoy the
enhanced imaging of forward-firing speakers. However, since I'm often
puttering, cleaning, doing dishes, or typing on my laptop to the left of the left
speaker, I'm happier with omnis. And when I *do* finally settle into the sweet
spot for a focused listen, I'm plenty happy with what I hear.

08-03-12: Phasecorrect
Off axis dispersion is one of the great attributes of rear driver systems...one can be almost 90 degrees off center and still hear the separation of instruments, etc...I also enjoy the increased depth and relaxed presentation which lends itself to vinyl reproduction... ...these systems tend to focus on what the recording is doing well.

Maybe that's part of why I can spend hours on end spinning vinyl through my Mirage OMD-15s. They are also the first speakers I've had that reveal inner detail well while keeping it in musical perspective. Separation of instruments and voices is probably behind that. In particular I noticed the subtle blending of wordless vocal backup effects that I often didn't know were there.

Anyway, the idea that rear-firing and omni speakers create an indistinct but large smear of what's on the recording doesn't match my long-running experience. You can hear deeply into the soundstage--and therefore--the recording.