Duntech vs Dunlavy?

I own a pair of old Duntech Sovereigns 2001, and I'm curious about his sound compared to his brothers Dunlavy SC-V and SC-VI. There are big differences (apart of the bass response in case of the SC-VI) in transparency, transients, or extension of the highs? Could be recommendable and upgrade from the Sovereigns to the SC-VI (or SC-V)?
I would say that the bass in the Dunlavys might be a just a little faster or tighter (the Duntechs need a lot of power and current to control their woofers, otherwise they can sound muddy in that range), and the highs might be just a little more extended, but all in all I think it's a sideways move, not necessarily a step up. The Sovereigns are a classic design, use better quality parts, and still hold their own even now if you want to hear the music rather than the recording. Plus I believe they have factory service still available (my old Princesses needed replacement drivers at one point, they had the exact spare pair matched for my speaker (we're talking the serial number here, not just the model) in stock). If you want to use a tube amp, though, I think the Dunlavys are better with tubes, the Sovereigns are better with solid state. The Sovereigns need a lot of power to truly come alive, more than the Dunlavys, but when they do there are few speakers that can match them, IMHO.
the sovereigns are still regarded as reference loudspeakers...period. they have also become incredibly rare since the owners won't part with them.
Rcprince, at least until one year ago Duntech gave support to the old Sovereigns, and also they tell to me that this model is still in production and in a very competitive price.
My Sovereigns are biamped with a digital amp (Yamaha MX-D1) for the bass and a tube amp for highs (ASL Hurricane). His sound is really good but as I never heard a big Dunlavy (very rare in Europe) and I always ask to me if they will sound noticeably better.
Recently I bought a pair of crossovers, from a younger Sovereign than mine (but with the same drivers), and I'm working to put better components as Mundorf caps and resistors... I hope that this upgrade will give a more open and detailed sound to this good speakers.
Carlesdg, while I have experience listening to many models from both Duntech and DAL, most of my opinions are based on owning a pair of Duntech Princess for 19 years.

While I admire the DAL models and agree with most of Rcprince's comments, I believe the Duntechs are a better overall product. If John Dunlavy was still with us he might disagree but I believe he made compromises to keep costs down when he returned to the US and started DAL. Two obvious examples are the drivers (no longer Dynaudio) and cabinets (simplified the step-back baffle which for my ear reduced some of the open, minimal boxlike sound). When set up correctly, both the Princess and Sovereign can sound more like a quality small monitor speaker, in terms of low colorations, than most other large speakers. Yet they can produce full range, large image, and great dynamics when called for.

Concerning amplification, during my years of ownership I tried many different SS and tube designs, including some passive bi-amping. Only three combinations were fully successful and one of those was marginal. The latter was a pair of AtmaSphere MA-1s which lacked adequate power but were magical with small group and lower sound level recordings. The best full range tube amp was a pair VTL 300s with KT-90s. The top SS was a pair of Halo JC-1s. Apparently the DALs are more efficient (regardless of ratings) and may be happier with less drive so smaller tube amps may work.

If you do a search on A'gon you should find good info from owners who have performed mods to Duntechs or DALs, including crossover parts.

Good luck.
Pryso, I have personal messages from other goners that also believe that the Duntech are a overall better product.
As I told before I, have a mixed amplification: tubes/digital, and I should add that I have also an digital active filter (BSS-336) but only in the bass path, in order to adjust the SPL of the woofers and correct the room modes. For me (and many of my audiophile friends) the sound is very smooth and detailed, with fast and clean bass, but with the big and focused soundstage and, when required, with the high dynamics and SPL that this speakers can produce.
I always thought that the floorstanders from both companies sounded as if they were cut from the same cloth. If you like a given model from one company, my guess is you'd like the other's equivalent offering. Beyond that, as to which YOU would prefer, it gets down to nuance and personal taste.

However, IIRC, Duntech was a different kind of company with a broader approach. For a while they focused on wall mounted dynamic models (actually sounded pretty good) and other quirky products. I always thought the switchover to DAL was more of a focused re-org thing, rather than any drastic change in the "voice" of the product.

A little more background might be of interest.

John Dunlavy originated Duntech in Texas (Dallas in the late 1970s I believe) with a 3-way, large box speaker (but not 6' tall like later models) which was adopted as a reference speaker by Big Bert White at Audio Magazine. The Duntech line was next expanded to include one or two wall mounted models (but fairly shallow, looking not unlike a picture frame) supplemented with a floor mounted woofer box. I'm not aware of any "quirky products".

By the mid 1980s, Mr. Dunlavy had moved his company to Australia and began developing the Sovereigns, Princesses and smaller models in the line up. Due to their size and weight, most of Duntech speakers were very expensive to ship, particularly to a major potential market like the US. So in the early 1990s Mr. Dunlavy returned to the US to supervise construction of a new, lower priced model in Utah, the Black Knight. After roughly a year, and for reasons I'm not privy to, he decided to separate from Duntech Audio which remains in Australia, and form a new company Dunlavy Audio Labs (DAL) in Colorado. With DAL he initiated the SC series which eventually numbered from I to VI. Like his floor standing Duntechs, the SC speakers were tall D'Appolito array, time and phase coherent designs. This suggests why there is such a similarity in sound between the two speaker lines. He went on to develop several additional speakers, not all of which made it to the market place. One of those was self-powered, tri-amped, with digitally compensating crossovers. While not inexpensive, in my opinion the DAL speakers were built more to a price point.

Unfortunately after age and health forced him sell DAL, it failed within a year under new ownership.

I've heard many of these speakers and while I have a few favorites, I respect everything I know of that John Dunlavy designed.