Planer/Dipole speakers: FAQ

[DonH50]

I would use the middle, that way you have room to move a little to each side or some slop ofr other listeners.

[A.wayne]

Hello,

I'm also in full support of not damping the front wall ( behind speakers) when it comes to dipoles, you will end up with a dead sounding speaker, diffusing works best here IMO , with any absorbtion being done to control reflections along the side walls at seat location( if listening near field.) or at the listening position...( far field)


regards,

[wineslob]

Hello,

I'm also in full support of not damping the front wall ( behind speakers) when it comes to dipoles, you will end up with a dead sounding speaker, diffusing works best here IMO , with any absorbtion being done to control reflections along the side walls at seat location( if listening near field.) or at the listening position...( far field)


regards,

I agree with this. Having owned Apogees for 6 years I can assure you that the front wall is VERY important. Small changes in speaker position, 1/4", can make or break the soundstage, as can listening position.
When I got the position "right" (per the Golden Ratio) albums would go from very nice, to, WTH, is there something/someone in the garage???(one sidewall is the back of my garage). Yes, the soundstage had no boundries. I could hear off stage noises that would not show up when the setup was not perfect. It was the "in the recording" not "looking at the recording from the outside" effect. At times, however, it could be very distracting, thinking someone is rummaging around in another room.

[DonH50]

The advantage of damping the front wall is that placement is much less critical and imaging more precise. The disadvantage, as stated above, is the speakers lose some of their "life". My front wall is heavily damped, for various reasons.

[RussellD]

The advantage of damping the front wall is that placement is much less critical and imaging more precise. The disadvantage, as stated above, is the speakers lose some of their "life". My front wall is heavily damped, for various reasons.

I believe this is the point being missed by so many in this sort of discussion is that the speaker should have no "life". The life should be in the recording.

The ideal listening room, allowing for the inevitable compromises forced by the practicalities of life itself, has absorption to deal with early reflections, flutter echo, and the inevitable bass standing waves. The typical error is inadequate bass damping relative to mid and highs, adding to the typical box speaker errors of over-resonant bass and bass-heavy room response due to directional mids and highs and omni bass and leading to a plodding, inarticulate bass range as heard in the room.
There are few commercial speakers that deal with the directionality in the bass range - Gradient and Geithain being two; the latter being an obscure German studio monitor maker.

In my old mastering room the front wall consisted almost entirely of a wide range trap, the side walls were convex, curving inward with a 14 foot radius curve, the front 2/3rds was symmetrical and the rear 1/3 was irregular and diffusive. It worked so well that the bass sounded essentially the same anywhere in the room - even if tested with a tone generator at any fixed frequency in the bass range.

[Grainger49]

Bruce, in re: Martin Logan planar dipoles, at least, Ethan has consistently advised owners to fully absorb the backwave, and many owners have followed that advice with excellent results. His assertion is that all of the information from the recording is contained within the front wave and that the back wave serves only to "confuse" the intended soundfield. Essentially, the unabsorbed backwave adds a form of artificial ambience while, as a result of comb filtering, reducing image clarity. . . .

I can see that the ML might really confuse the directional cues because of the curved surface. I think they are an ingenious design. My experience of 15 years with Servo-Static speakers was to toe them in for more direct sound to the listener. That also allowed me to use the back wave reflected off the wall behind them, then the side wall to open up the soundstage. I had to adjust the distance from the R/L panels to the back wall to get what I was seeking.

As always this changes drastically from speaker to speaker, even within the small category of electrostatic speakers.