Which speakers have rear firing speakers and how do they sound?


Stumbled across a review of the BMC Purevox which has a rear firing woofer and tweeter in addition to front facing ones. 

What other speakers use this same idea?
How do these type of speakers sound?

I'm curious how they'd compare to something like a Martin Logan


cdc2
I don’t disagree, the 2nd room, 3rd room, listening room all add.
even in the control room listening in the near field, there is bounce off the board, etc. mastering rooms not usually near field, etc...

I did some experiments with trying to replicate ratios along the chain, for example if the stereo pair was 9’ in the air and 7’ from small chorale and ... x you get the idea ( but the math is complex and results indeterminate, but think this is but one reason why stereo images vary in realism so much

happy listening 
Lots of good thoughts and comments. Question is

Which speakers actually get it right accomplishing both goals of
A. providing accurate sound replicating the studio recording with decent imaging
B. provide a sense of realism and space to give that you're in the room feel to the music

Possible solutions include:- Electrostatic and planer speakers like MLs, Soundlab, Magepan, etc
- Omnis like Ohm Walsh, or hybrids like Decware's HR-1
- Open baffle speakers like Spatial Audio's
- More traditional box speakers that include a rear or upwards facing tweeter and or midrange 

And of these - which works in more rooms than not? E.g. doesn't need to be placed 5 feet into the room and isn't the size of a barn door or cost as much as a new car?

Wow.. I know that's expecting a lot but interested in. your suggestions.


I have Vandersteen 5A’s that have a rear firing rear speaker that can be turned on/off via a volume control. Clearly it sounds best off as recommended in the owners manual. With the rear speaker operating, the sound is more diffused/confused.
@cdc2


"Which speakers actually get it right accomplishing both goals?"

I'm guessing that most of our experiences have been that all of the discussion regarding speakers and rooms is 'theoretical'...UNTIL...we get the speaker being considered in our own specific rooms playing with our equipment and our music.  When we begin tweaking the speaker location/position, we begin to understand...that it is very difficult to identify the 'one size fits most' loudspeaker....especially when you add the placement challenges of many rear firing loudspeakers.


There are plenty of people that own all of the speakers listed above and love them.  And there are plenty of people that have tried them and moved on.

Let me just pick one 'usually agreed upon' example.  Magnepans in the right room, with the right amplifier, the right positioning and the right type of music can sound shockingly real (live music)...but move them a little bit, change the amplifier or change the type of music and they seem to lose that magical quality.

So, where does that leave us.  I suspect that there are two solutions which from a practical standpoint, people often end up with:

First:  pick the loudspeaker that has the most positives and fewest negatives in your room with your equipment and music

Second:  have two systems in two rooms that have different strengths and play the one that suits your mood at any given time



Cdc2 wrote: " in search of the most live sounding speaker - suggestions? "

Cdc2 breaks it down for us: "Which speakers actually get it right accomplishing both goals of

"A. providing accurate sound replicating the studio recording with decent imaging

"B. provide a sense of realism and space to give that you’re in the room feel to the music."

And cdc2 takes the real world into account: " which works in more rooms than not? E.g. doesn’t need to be placed 5 feet into the room and isn’t the size of a barn door or cost as much as a new car? "

I am a SoundLab dealer, and imo SoundLabs set up properly do a very good job of recreating a "you are there" type of experience. But accomplishing that does require placement a good 5 feet out into the room... they are approximately the size of a small-to-medium barn door... and it depends on the car...

My mentor in loudspeaker designer is Earl Geddes. Earl is a master of ultra low coloration and room-friendly design.

The SoundLabs (when given their 5 feet of real estate) create more of a sense of being enveloped in the acoustic space of the recording than Earl’s speakers do. Earl’s are more dynamic and are every bit as low in coloration and vanishing as the apparent sound source.

I build speakers inspired by Earl’s design principles, and then I add additional late-onset reverberant energy via drivers aimed to bounce off the wall behind the speakers, and then off the ceiling, before reaching the listening area. So conceptually similar to what you saw with the BMC Purevox, except that my rear-firing drivers are not identical to the front-firing ones, and they are mounted as close to the floor as I can reasonably get them. Also, my rear-firing drivers are level-adjustable, as we found there to be a "sweet spot" in loudness relative to the front-firing drivers, and dialing it in for different rooms requires some adjustability.

One difference between what I do and all of the speakers you listed above is, my speakers use horns. Low-coloration, constant-directivity, waveguide-style horns. Their pattern control helps us minimize early reflections, and it is primarily the early reflections which superimpose a "small room signature" atop the spatial information on the recording. Of courese if my horns have audible horn signature then all of this is of academic interest only.

I am NOT going to claim that my designs do what you want - that’s a subjective evaluation and I’m the last person in the world in a position to make it without bias. Instead, I’ll say that I think my goals are similar to yours, and that I’ve tried to incorporate design elements that at least theoretically might work.

My website is being revised so contact me if you’d like a link to a recent show report with some good pictures.

Duke