My MBL 116F are omni down to 620hz, sidefiring cones below that.
They work wonderfully well imo.
But they do cost the earth.

The best speakers I have ever heard in my life used electrostatic line-source panels fired through an acoustic lens. They radiated in a 180 degree pattern and were intended to be placed with the cabinets arranged to face each other (not the listening position), with their backs up against adjacent walls. So, one on the front wall and the other on a side wall.
I can't begin to express how good they sounded. They were the Beveridge speakers and produced what was known as the 'Beveridge Cylindrical Sound System'.

I wrote a little about them here.
TAS thread number 72, so it's going back to the forum's early days!

There's an interesting piece about the technical details here on the Beveridge Audio website. 


I was never able to house or afford a pair of those and the nearest thing I came to it is the speakers I currently use - Mirage M-3si, which are described as a bi-polar design: back and front facing duplicate drivers wired in-phase with each other.


Interestingly, the Beveridge site I linked to above mentions a design where two drivers are aligned face to face and wired out of phase, which is exactly what John does with his scaffold beasts.  This approximates the pulsating spheres in Jerry's speakers.   

I've heard the big MBLs (not Jerry's model) sound awesome, so I'm not averse to the technology. Smaller older speakers like the Sonabs didn't leave much impression.

I saw a chap on Facebook found two very solid side tables with chunky corner legs and was going to convert them into speakers by panelling them. I immediately thought of you and converting them with a top omni driver and opposing (or even four) bass drivers.

Maybe you'd like to try your hand at building some...

DIY MBL Speakers

I think  a diy MBL is way beyond me unfortunately as is being able to afford and house a real pair.

With four tweeters all at 90 degrees to each other I suppose I gave what is known as poly directional. I thought about trying the Shahinian approach of firing several tweeters at angles towards the ceiling. Maybe I will give that a go. The only other thing that I could do is use a diffuser(s) like Duevel. Anybody heard them ?

With my speakers being in a small room they have to be close to walls so I only require 180 degree radiation. Most omni and pseudo  omni need to have space behind them. I'm not too bothered about imaging and soundstage, I am willing to sacrifice it for other aspects I find more important but if I can have it all then all the better.

I already have bipolar mid bass with up and down firing 6.5 inchers doped and run full range and in phase (electrically).

I am particularly interested about the two drivers face to face and wired out of phase. How does this work ? Where can I find out about the concept ? I take it there is a gap between them otherwise it is just a compound isobaric driver.

Many thanks, Stu

Thanks John for taking the time to explain this. I take it that this arrangement only works in the bass region ? If I were to do that with mid bass drivers that are run fully open it would probably be a disaster. My high pass filter corner frequency for the tweeters is at 9.5 khz. And I don't have loads of power but listen in a small room at low volumes.