Don't laugh at the ratshack 'lytic cap, the CAT5 speaker cable, and the Obligato taped to the back of the board.

I've seen much worse.

By the way, try one of those Linkwitz' designs, they really take names once fitted with proper speakers.

I've seen much worse.

By the way, try one of those Linkwitz' designs, they really take names once fitted with proper speakers.

I'm going into a totally different direction from Linkwitz. He's into active x-over and EQ with op-amps, inefficient poorly behaved, but very precise sounding metal drivers, 88 high powered solid-state amplifiers (one for each driver), etc.

I'm into tubes (namely SET) + efficient drivers (at least from bass on up); and I won't touch op-amps for x-over or EQ in the critical regions (been there, done that.) I'm also done with inefficient poorly behaved metal drivers which require 8-order x-overs so they don't end up sounding like aluminum pots and pans banging on each other.

Just opposite philosophies and tastes.

Interesting, though it's worth noting that the majority of commercial fully OB designs (as far as I'm aware) use some form of active EQ, so you end up with room EQ anyway. There's also arguably more of a need for room treatments with dipoles and OB designs in particular than with traditional box speakers, and especially compared to FR enclosures or constant directivity horn types. FR enclosures for example should need little more than bass traps.

The typical treatments I see with traditional dipoles like ESLs or planars or OBs is to try to "black hole" the wall behind the speakers with absorption, though I've found that diffusers can actually be more effective, though trickier, as you want some reflection, just not right away. Linkwitz argues for >6ms IIRC, but I've heard other designers recommend >10ms. The other option is to pull your dipoles 6+ feet away from the wall, but of course that's often not practical.

Jamo made a passively-EQ'd dipole, the R909. My preference is bi-amping with active equalization. With dipole woofers you can use a simple 6dB/oct lowpass filter with gain to do the EQ and the gain can be performed through opamps, transistors, or my preference triodes. The same can't be said for room EQ which needs parametric EQs and preferably done in the digital domain to minimize signal degradation.

In the bass region I would say dipoles need less room treatment than box speakers, which need bass traps and more. In the midrange and treble, both dipole and traditional moving coil speakers have similar front radiation into the room with attention needed for first reflection points, etc. Dipoles do have the extra radiation from the rear which some people prefer to leave untouched. Linkwitz talks about illuminating the room evenly across the frequency spectrum and I see his points. Others use mild room damping.

LOL, I've been moving the speakers up 1" per day from the back wall in hopes my wife won't notice. You are probably right, it's the back wall reflections.