For as long as we have been manufacturing speakers, we have received requests for a true end-game speaker. A speaker that provides class-leading performance in all the critical performance areas.

• Accuracy
• Detail
• Dynamic capability
• Directivity
• Wide dispersion
• High frequency linearity and extension
• Non-fatiguing
• Bass extension and midbass punch
• Low distortion
• Good efficiency
• Power handling
• Accurate transient reproduction

This list goes on and on…

Achieving a few of these lofty goals is difficult enough but attempting to achieve all of them is a highly complex engineering challenge and almost impossible. To achieve one design goal, sacrifices in other goals must typically be made.

Our towers were introduced 11 ½ years ago and have truly stood the test of time, other than a few cosmetic changes, we have never made even a single change. We have almost always run a constant backorder, selling out continuously.

With our newer and NFS optimized EX and LX speakers, we have come very close to matching the performance of our towers. Both the EXv2 and LX have surpassed the towers in certain very specific performance characteristics, and this was our goal. With the LX, we surpassed the towers in overall dynamics, bass extension and power handling – with the EXv2, directivity and midrange accuracy and detail.

We have closely tracked and logged all customer feedback on these 3 speakers (Towers, EX and LX). This critical data was the catalyst to developing something truly special, world-class products that compete with and even surpass nearly all other passive designs.

One of the reasons this took us so long was that a few key elements were missing. One of those were our incredible LX woofers, which have now been fully vetted and tested being in the hands of hundreds of customers with our Sierra-LX. The dynamics, bass extension and sheer power these woofers provide is unmatched and has been proven as such. When designing these woofers, it was always our intention to be able to use them in our towers, and they were designed and optimized as such. We just needed to amass enough feedback on them and now we have it.

With our Sierra-2EX V2, we were able to achieve text-book perfect directivity with our EX woofer and RAAL ribbon tweeter, and feedback from the V2 has far surpassed our expectations.

The last missing element, our Klippel NFS. Having the most advanced acoustic R&D device at our disposal allows us to put this all together in a manner that very few audio companies are capable of.

It has always been our intention to offer an end-game product, but we weren’t going to do so until all the critical pieces were in place, and I am so pleased to say that this complex puzzle has been solved. And, in such a way that this product clearly defines that age-old adage “The whole far exceeds the sum of its parts”. Considering every component used is truly top-of-the-line, that is a bold statement to make.

The real key to this project is in the unique crossover topology that we have been working on and trying to perfect for over a decade now.

One of the problems with 3-way parallel crossovers is that there needs to be a very large capacitor in series with the midrange driver to form the high pass filter, which gently rolls off the lows. Such a large value series capacitor in series with the critical midrange driver causes some unavoidable issues. Amongst these are a large phase shift, distortion, and it also dampens dynamics. Then, to increase the high pass filter slope from 1st order to second order (12dB/octave) – you then must add the appropriate inductor in parallel after this capacitor. This then takes lows that should not reach the driver directly to ground.

To filter out the highs that are meant to go the tweeter, you then also add a low pass filter, (a series inductor with a parallel capacitor) – thus completing what is known as a bandpass filter for the midrange driver. The tweeter then uses a separate high pass filter while the woofer uses a low pass filter, and then these 3 filters are wired in parallel. This is the standard for crossover designs for 3-way speakers. It is a tried-and-true design, relatively simple to design and when done right, provides good results.

I have had an idea in my head for a different 3-way crossover topology for what must be 25 years now and we started work on this back when we first developed our towers. We made several samples, and the results were good, not great – and not better than the more simplistic and common crossover design we eventually went with.

With help from advanced computer modeling and hundreds of hours of NFS testing, we have finally been successful in developing this different crossover topology, that avoids the negatives of a large series capacitor as described previously while also routing much of those low frequencies that would normally go to ground, to the bass woofers.

The results are amazing, driver integration and overall directivity is about as good as it gets for a passive loudspeaker. Coherency is on par with the best 2-way speakers, yet this is a true 3-way. Dynamics are astounding as is bass response as this new crossover design mitigates those losses as I outlined above. Because phase response is more accurate, directivity is improved and this results in remarkable spaciousness, but not overly so such that center imaging is still focused and not dispersed.

We lose a small bit of overall efficiency, but this is offset by presenting an easier impedance load to the amplifier, so the amp uses less current and as such, has more headroom available.

In simple terms, this new crossover brings out the maximum potential of each transducer, sums them ideally and the results are clearly and instantly audible when it comes to dynamics, spaciousness and imaging.
For many reasons I won’t be publishing details on the circuits themselves, but it functions differently than a 3-way parallel crossover and the results have proven to be better than I had expected. I am honestly not sure if it would have been possible to properly design this without an NFS.

This is a unique, expensive, highly complex, 2-layer crossover that, with specific optimizations that we perform by hand, serves as the brains for 4 new versions of our towers, and 4 new versions of our Horizon!

Stay tuned....