Open Baffle Experience

Not all OB have open back tweeters.  The Spatial audio x series have open back tweeters and their M series do not.  If you cannot have about three feet from the front wall then a powered open baffle such as the X series and other open baffle speakers that have powered controllable woofers would make sense as you could increase or control the bass quantity to match your speaker location.  Sure if the speakers are only two feet from the front wall you would probably also lose a bit of spaciousness as compared to at least 3 feet.

Just a comment on the arguements and divergent opinions re: Box vs OB

Almost Nothing Good comes without a Struggle...

OK, continue your jousting...

Hey @emrofsemanon 

You have it mostly right... an "infinite baffle" is a situation where you have a theoretical infinite width and height wall on which the drivers are mounted. 

The open baffle uses both the rear reflection but also the nulls to the sides. The idea is that you get less side reflections, but also quite a bit of ambience which can help improve imaging from the rear.

@johnnycamp5 wrote:  "I should be more specific - Are all OB open back tweeter? I thought some had forward only directivity . So the heavy drapes question was more for the mid range and bass frequencies."

Yes, some open baffle speakers have rear-firing high frequency energy and some do not.

@johnnycamp5 again: "7’ off front wall is always why these types of loudspeakers (dipole) are “non starters” for me... I’ve always been attracted to horns for their controlled directivity.

"But man that open spacious sound of OB is hard to beat if set up right…just a whole different flavor of goodness."

Very interesting.  Ime that goodness depends on having an adequate reflection path length for the backwave energy.  Linkwitz recommends a minimum of 6 milliseconds (approximately 6 feet total, corresponding to about 3 feet distance from the wall.  I shoot for 10 milliseconds delay (corresponding to about 5 feet from the wall), based on the writings of Earl Geddes and David Griesinger.

I'm into both dipole speakers (as a dealer) and horns (as a manufacturer), and agree with your observations about "the open spacious sound of OB".  So my horn speakers usually have user-adjustable rear-firing horns which are angled up-and-back, such that their reflections bounce off the wall and off the ceiling before reaching the listening area.  This way they can be placed within a foot or so of the front wall and the reflection path delay will be in the 10 milliseconds ballpark. 

My approach would not work well with heavy drapes behind the speakers, as they would absorb the high frequency energy.  Imo it is desirable for the reflection field to have approximately the same spectral balance as the direct sound for a variety of reasons, which I can describe if you wish.

Duke