
Thought a rainy day in a San Diego might be a good time to update the build post.
To make a long story short, I never fully warmed up to the 1st order crossover that Troels designed for the
Ellipticor III. I listened for a couple of weeks, but missed the dynamic range and midrange of my Altec’s. I also have a lot of experience with ScanSpeak drivers. I thought there was more resolution and dynamics hidden just waiting to be tapped. These drivers are really state of the art.
Soooooo. I sent the speaker off to GR Research for a measure and redesigned crossover. Danny rethought the whole design based on his measurements and years of experience. Full disclosure. I am a huge GR Research fan. I own several speakers with Danny’s design work and have built 2 of his reference designs over the years.
The pic shows the new pair of crossovers complete with Sonicaps and Miflex copper bypass caps. New Erse coils and mills resistors. Drivers were also re wired with GR solid core hook up wire and tube connectors installed in place of the big metal binding posts per Danny’s recommendation.
The new design is just over 90db efficient and a smooth 8ohm impedance is very amplifier friendly.
It’s a different speaker now. Still a great enclosure. Troels is a great box designer and PBN builds the best wood enclosure in the business. The drivers are keepers too they all blend nicely with the Ellipticor Tweeter being the standout in the group. It is shocking in its dynamic power and transparency. Danny rolls it in smoothly at about 1250 hz. The payoff is imaging. These big speakers just disappear. Voices are suspended mid air with lots of ambient information. The sound stage is also crazy wide. In my room and for my ears, that’s a good thing. One of my concerns with controlling direction of sound is the sound stage can get closed in. The benefit of course is less room interaction. A bit of headphone effect I suppose. I’ve played with both, thankful we are free to choose what we like and what works in our room.
The 6” Ellipticor is in it’s sweet spot operating up to 1250 hz. The little bump in the impedance at 1500 hz is gone with the new filter. This driver is really good, the midrange in this design is smooth yet dynamic. No audible coloration anywhere in it’s current operating range at all. Very few speakers can make that claim regardless of price.
The 8” Ellipticor is bit trickier to implement. Danny rolled It out above 200hz because it gets a bit busy up top. It does add some impact to the upper bass and helps free the 6” Ellipticor driver from large excursions, so you could say it serves it’s purpose and does it well. It is a great bridge between subwoofer and mid woofer. Not sure how it would perform with broader range. Someone will have to experiment with more time and money than I have.
The downfiring 12” sealed GR Research servo sub is just a Rock Star. The bass in this speaker will crush most crazy expensive big name models. The PEQ 370 servo amps also relieve my amp from sub bass duties. The sub section is tight, tuneful and deep. Tons of ambient cues and “room feel”. When called for, it jumps into action and makes the whole room pulse with deep, pure, bass. Taurus Riley has never been more fun.

To summarize, I’m really happy. The design was well worth the expense and effort. It’s a reasonable size and checks all my audiophile boxes. My wife loves the way they look. I spend more time listening than I have in years. It’s hard to break away at night and go to bed. Just one more song I keep thinking.
With the 1st order crossover, they were good. Sounded like a warm electrostatic. There were some deviations from accuracy that I couldn’t live with however. The redesign with steeper slopes and Danny’s well placed high and low pass choices is stunning. The transparency of a electrostatic is still there. I think that may be the quality of these stunning drivers and a great box. The drivers have great settling time. Now they have the dynamics and detail I crave. Music without lifelike dynamics lacks emotion.
I love Open Baffle, horns, stand mount monitors and most anything that sounds good. This design is just right for my room and lifestyle right now. Keepers.