Howdy Linkwitz people!
Like many, I benefitted greatly from being local to SL. I had many occasions to visit his home to listen and talk audio. I still use the Orions today, as well as Plutos (both made by local Don Naples at Wood Artistry).
I'm looking for advice from folks with experience with SL's designs, and other controlled directivity designs.
I'm in the process of upgrading my setup for home theater 7.2.6. Orions as mains, plutos as rears. Will likely use 2 sealed Rythmic F18 subs, jointly optimized with Dirac Live Bass Control. I recently purchased 6 active iLoud MTMs for side surrounds/heights & rear heights, as they need to be close to the walls and right around my couch in the near field.
The advice: I'll be adding front L & R "height" speaker's directly above my Orions, ceiling mounted, and an elevated center channel as well. What would complement the Orions well?? (I didn't have a center before because my Orions flank a 133" screen. But if I'm mounting heights, I might as well add an elevated center).
It's possible I can have 5 dipoles in the front!
A seeming no-brainer would be to build 3 LX521 top sections and mount or hang from the ceiling. They would cross over to the dual subs. This could be the ultimate dipole setup.
The deal-breaker is probably just the size--each LX521 top baffle is ~2' high, so together with the Orions I'd have a wall of dipoles. Ceiling is 9', so there is enough space--it would just be visually dominating, like a dipole archway
So, some brainstormed options:
1. DIY a smaller dipole. I could build a baffle as small as 7" wide by 9" high by using a magic 6.5" woofer with extreme volume displacement capability, yet low distortion. The
Purifi woofer could be that woofer. That could be crossed to a pair of slim 1" dome tweeters, such as these
Bliesma tweeters. They would fit back to back if the baffle is made from 2 layers of 3/4" plywood.
It would sort of be like a mini Orion top baffle, but with less of a jump in driver size, which could help with the crossover (this ultimately led to Linkwitz experimenting w/ a 3 way top baffle, to control directivity better). Or like a 2 way LXMini top with a bigger jump in driver size, but smaller, and closer to the "minimum width baffle" idea (vs the Orion).
+ Would be fun to design and build
+ Pretty confident I could find the optimal crossover for a good directivity match at the crossover region
+ Pretty confident I could get the dipole & driver EQ right
- Unlikely I'll hit upon the optimal baffle shape. I can't easily make and test completely different baffles, so I hope a simple rectangle is optimal
- Unlikely I'll end up with a perfect dipole directivity at every frequency. Though, I'm not sure the Orion or LX Mini do either
- Unlikely I'll end up matching the master in total performance
2. DIY an acoustically small, sealed box, with waveguide. Similar to what SL was
experimenting with in 1978, even down to hanging them from the ceiling. The
Seas DXT tweeter + the Purifi woofer would be a good match.
+ Pretty confident I can get nearly perfect directivity control from a few 100 hz on up w/ the woofer to waveguide tweeter, because there are several designs that have done this well, such as the
Idunn &
DXT Mon 182
+ Confident the crossover & EQ should be no problem
- Will have different room reflections, so may not blend as well. Not really sure if this is a problem.
- If there is dipole magic, this won't have it. I think there's a good chance of building an exceptional sealed box speaker, so it would be good for what it is. If I made a dipole, I wouldn't be as sure.
3. The easy way: buy 3 coaxial speakers. The newly released KEF LS50 Meta have
exceptional spinoramas.
Up there w/ the Genelecs, it seems.
they are quite inexpensive, but only sell in pairs. So I'd buy a pair for L & R heights, and buy a beefy Genelec "Ones" speaker as the center channel ($$$) to keep up w/ the Orion mains. And the coaxial design could be a benefit because these will be mounted at ~30 degree elevation, where vertical directivity perfection could be more important (though I'll make sure to be within the vertical sweet spot either way).
+ Easiest option
+ Kefs are inexpensive
+ Steller Spinorama measurements
+ Tried & true, should be easy to sell if needed
+ Uncertain again about how well they'd mesh w/ the dipoles
- I'd have literally 5 different styles of speakers in my surround setup--Orion, pluto, iLoud MTM, KEF, Genelec...
- Ported. We know SL is not a fan of vented monitors because of poorer transient response/group delay that's not correctable. I'm not sure how audible this is.
- Genelec center would be expensive
I will EQ all the surrounds anyway to the same house curve to match the Orions, so I don't have wild timbre changes.
4. DIY compression horn kit. This is the wild card. A big, efficient horn (Seos 15 oblate spheroid waveguide w/ Celestion compression driver) + 12" woofer could be the center channel. This is way too big to mount in the same location as the above, but it could instead be mounted on the front wall, above the 133" screen, clearing space in the middle of the room. This would be the
Diysg HTM-12. L & R heights could be the smaller
HT-8, still going above the orions.
+ Super duper cheap
+ As with all/most of the above,
stellar directivity control
+ High efficiency so no problem w/ SPL even mounted further back
- Center would be much further away. Phase/delay would be perfect at listening position, but may sound weird when listening from the adjacent room (though not sure how much would come through the center channel for casual listening from a different room while puttering around the house, even w/ Auro 3d upmixing on)
- Still not sure about mixing different directivity designs w/ dipole, or whether it matters
- The main guy is moving and not sure when they'll be in stock again
- Ported
Wow, that's a lot. Thoughts?
A couple photos of the layout. Pretty good for a dipole setup. Almost perfectly symmetrical room. 6' in from front wall. 2' from side walls, but the little bit of side wall is in the null, and the entire side wall between the Orions and LP is completely open to the rooms on both the right and left sides. So the earliest side wall reflections are elmininated (transmuted to much later reflections as they come back from the adjacent rooms).
