directional speakers

@paradisecom I've actually never heard ML's but will be sure to stop by their room at Axpona.  Thanks for the recommendation.

@yogiboy Interestingly, the advice I got on the Spendor user's forum is to look into the Graham Chartwell LS6.  If I stayed in the Spendor line what would you suggest, one of the Classics?

@yogiboy - Sorry, I should have mentioned that my wife graciously  suggested that I use our 23'x16'x8' TV room for the audio system and move the TV to the smaller room where the audio system is now.  That's why I was thinking of the larger Harbeths.

By the way, which version of the P3 do you recommend?  I've noticed that there is some difference of opinion on the XD.

@audiokinesis I believe that you are correct.  Here is what the Theoretica web site says:

BACCH® 3D Sound will greatly enhance the spatial fidelity of sound reproduction through any loudspeakers. Loudspeakers that have high sound directivity² will give the best and most accurate 3D imaging in a highly refelctive room with little or no sound treatment, as room reflections, which degrade imaging, are minimized by such loudspeakers.

However, even loudspeakers with low directivity (i.e. omni-directional loudspeakers) will give a spectacularly spatial soundstage with BACCH® 3D Sound in a typical listening room. As the importance of room reflections is decreased (by increasing the ratio of directed to eflected sound through room treatment and/or higher-directivity speakers and/or nearfield listening) the image’s depth and 3D imaging approach the depth and spatial characteristics of the original sound field.

An ongoing investigation of speaker directivity at Princeton University's 3D3A Lab, has shown that dipole speaker designs, electrostatic speakers, as well as speakers with horns and waveguides offer significant advantages in 3D imaging with BACCH® 3D Sound in highly reflective rooms, as they increase the ratio of direct to reflected sound. Abating early room reflections with physical room treatment (i.e. using sound absorbers on sound-reflective surfaces) in a listening room is always beneficial to any audiophile-grade sound system. For BACCH® 3D Sound the effect of sound treatment is equivalent to using loudspeakers with high directivity, or listening in the nearfield. The more directive the loudspeakers are, the less sound treatment is needed for BACCH® 3D Sound to produce a full and accurate 3D sound image.

Therefore, in a reflective untreated listening room, directive loudspeakers are more desirable. In a well treated listening room with sound-absorbing surfaces, any loudspeakers, even omnidirectional ones, will produce an excellent 3D image.²

Budget is in the neighborhood of $5000; used is fine with me.  The speakers will be placed in front of bookshelves filled with books.  I could place the speakers 18" to 24" from the wall.

@asvjerry The truth is I've never done "normal" well in any domain.  Why start now?

Seriously, the object of the Bacch system is to eliminate crosstalk, as I understand it.  We will see if it is worth the money.  It's an experiment, but no different than trying a new amp or DAC.

The Bacch system is going in a room as yet untreated, but I will get to that this summer.  Main reflection points on the ceiling and side walls will get primary attention.  Not sure about bass, but I have two tube traps that can be moved around.

I (and my wife!) am quite enjoying the small Spendors driven by the modded GaN1.  I just thought that now would be a good time to consider other speakers - and so I will look into the Harbeths, ATC's, the ML, the Fritz and Zu's. My read of the Theoretica info is that in a well-treated room speaker directionality is not crucial for what the Bacch does.  However, I don't want to defeat the system by getting speakers with wide dispersion.  My guess is that among the recommended speakers I can get the SQ I want and not do anything that defeats Bacch from eliminating crosstalk.

Thanks very much for all the advice above.  It's very helpful.

Tom

@audiokinesis The tradeoff you describe is very interesting.  I,too, would choose imaging precision, soundstage depth and clarity over soundstage width.  We'll see if Bacch allows me to have my cake and eat it too.

Thanks

@audiokinesis Everything you say is consistent with my understanding.  I'll report back in a month or so when I get the Bacch system up and running.

@elliottbnewcombjr Thank you for the detailed response.  I have already adjusted the toe-in to try your "Adjusted Toe-in" method to enhance imaging. 

In your comments, however, it occurs to me that you do not make them in the context of a Bacch implementation, which I made quite clear in the OP is what I am doing.  Your recommendations may be valid generally, but I'm not so sure of their validity in a Bacch implementation.   Could you confirm that your recommendations hold within a Bacch implementation?  Have you familiarized yourself with the Theoretica literature so that you know what Bacch does?

Thanks in advance for your clarification.

@elliottbnewcombjr Fair question about the theory behind Bacch.   I'll respond as best I can, but the truth is I'm close to being over my head.

In a nutshell, Bacch is a specialized time-domain DSP intended to eliminate crosstalk without coloration.  Theoretica claims that their customized Bacch filters do not have the spectral coloration added by previous attempts at crosstalk elimination.  A Bacch implementation includes calibration using in-ear mics and Webcam head tracking so that the sweetspot follows the listener's head, within reason.

That's about the best I can do.  There is more on Theoretica's website under FAQ, but you may want to look at Edgar Choueiri's book Immersive Sound on Amazon.  Choueiri is quite willing to talk to people about Theoretica's work so I would encourage you to reach out to him, or stop by Princeton if you are close.  If you do have a conversation with him I for one would be very interested to hear your reaction.

Regards, Tom

@jon_5912 Thanks for the heads-up on ATC directionality.  I will, of course, take advantage of any opportunity to hear them as they have a great reputation but they are probably not ideal for my application.

Regards.