Fully active Klipschorns?


I'm not looking to buy, but often when I look at the physical design of these corner horns with the folded bass section I think to myself "Wow, these would be great candidates for a fully active, DSP crossover!" 

The tweeter, mid and woofer are so far away from each other acoustically I often wonder what they would sound like properly time aligned.  I can't be the only one who has thought about this, can I? 

erik_squires

The tweeter, mid and woofer are so far away from each other acoustically I often wonder what they would sound like properly time aligned. I can’t be the only one who has thought about this, can I?

Absolutely not, Erik. If I remember correctly John Atkinson in a comment in the comments section to (the late) Art Dudley’s review of the Klipschhorn AK6 remarked similarly, and how an actively configured DSP implementation of the Khorns would benefit them, or was certainly an intriguing prospect to ponder - a sentiment no doubt aided by his measurements. He went on to suggest a 5-way approach was necessary to address the limited bandwidth of horns in an all-horn setup, certainly aiming for a full-range ~20-20kHz capacity, but that’s also inviting issues with a rather daunting task of integrating 5 driver/horn sections, an aspect I’m sure he was well aware of. Personally I believe an active/DSP 4-way properly sized all-horn approach would be sufficient and do excellently, while a successful 3-way attempt is fully in the cards as well, albeit likely challenging clean extension beyond 17-18kHz.

The real issue of the Khorns, however - apart from the need of an active DSP-implementation - is the lack of appropriately sized horns, i.e.: the midrange and bass/midbass horn in particular; with a folded bass horn and 180 degree bends issues easily arise above ~300Hz, not to mention consequences from throat constriction and air velocity here in conjunction with a compression ratio set too high (to aid upper band extension). Which is to say: a limited bass/midbass horn size creates issues that invite corrective design measures that in turn creates additional issues. With regard to the midrange horn a larger ditto (and driver exit diameter) would more properly load at lower frequencies to better meet the bass horn here, while maintaining directivity all the way down to the crossover point - not at all trivial.

My previous main speakers were passively configured all-horns and an homage to the Klipsch Belle speaker. Their issues in the bass horn section over time become a growing concern of mine, which led to digital correction measures to alleviate a 120-140Hz peak and upper band irregularities, while also high-passing them to a pair of horn-loaded subs but without being able to stretch my tapped horn subs to above 100Hz, below which the midbass horn stopped acting as horns. I briefly considered trying out converting them to active configuration via DSP, but soon realized I would be working from an overall horn package too small, and instead went on to pursue new main speakers that are actually horn hybrids (oh, dear), but with properly sized MF/HF horn and a matching dispersion pattern at the cross-over to dual vertically mounted 15" woofer/mids. Down the road I’ll be implementing a properly sized midbass horn and thus finally arriving at an all-horn approach that seeks to do it more justice.

Working from correctly sized horns, at least within minimum requirements to have them actually act as horns without named negative side effects, is paramount to deliver their fuller potential, but this (i.e.: large sized horns) goes contrary to most domestic expectations of having a speaker package (much) more limited in size - something the Khorns, without in any way being small per se, still seeks to abide by as all-horns aimed at the domestic market.

Indeed, most so-called "horn speakers" are really horn hybrids with a mixture of horn(s) and direct radiators, mostly too small at that, and yet many - from this point of reference mainly - faults them as "horn speakers" seemingly without realizing they’re potentially both right in calling out a deficiency of a hybrid design usually too small, while at the same time providing a disservice to horn speakers - and as such: all-horn speakers - judging them as that which they’re really not.

All of which to still say: yes, I’d definitely prefer working with the Khorns from an active/DSP outset. That alone would no doubt lift their performance envelope, while not being able to address the other core issue of limited horn size.

I use a DEQX DSP with my fully horn loaded DIY speakers; Bill Fitzmaurice HT Tuba folded corner horns, Oris 150 horns driven by AER BD3 drivers and Fostex t900a super tweeters.  I feel that the results are excellent.  The folded bass horns are back in the corners where they need to be and the mid and tweeter horns are well out in the room where they can image better.  Counting the horn path inside the bass bins plus the physical separation between the horns the acoustic centers of the woofer and midrange drivers are over sixteen feet apart.  With the DEQX the timing is corrected so that the acoustic centers of those drivers sound as though they are within less than 1/8" of each other.  With your Khorns I also feel you would get great benefit from speaker correction, room correction, etc.