My dedicated audio room build - QuadDiffusor's Big Dig

The Linkwitz LX521.4 system was outstanding - no - astonishing! The digital source was in plain-old CD resolution, streamed via an integrated streamer/DAC with no fancy ancillary cables or other equipment. I can expect that with a statement streamer like the Aurender N30 or Taiko Extreme with the newest (and greatest) DAC from MSB, the Cascade, the performance will be even more delicious.

It was pure serendipity that I was able to stumble upon the demo room by chance during the last hours on the last day of Munich Show off the beaten path inside the adjacent Automobile Museum venue. I was grinning ear-to-ear when I heard the system which discretely and effortlessly fleshed out the individual and collective molecules of any/all performances in the correct natural spectral balance and 3D micro/macro dimensions/positions within the expansive soundstage. Music's able to climb, expand, explode, jump, juxtapose, punch, shrink, seduce, shimmer, and throb "behind that", "down there", "here", "over there", "way back there", "up there" dynamically and simultaneously within the spatially accurate, rich and organic 3D soundstage.

I find that this closely-spaced vertical array of dynamic drivers to be superior to full-height ribbons/planars in dynamically reproducing pin-point locations and sizes of discrete sonic events inside the soundstage. To me, the latter designs (Alsyvox, Magnepan, Martin Logan) are unable to persuasively layer, position or scale the height of sonic events from ping- pong-ball-sized orbs/spheres to symphonic-hall-sized (and everything in between) orb/spheres, but instead portray them as being strangely flat and mostly too tall (but ironically too short at the same time), locked into a uniformly unnatural horizontal which does not vary with listening position height.

While many may find a floor-to-ceiling soundstage height to be exciting, this mostly "full height" presentation is unnatural, equating to the The inability to scale the sonic event's relative "height" within the soundstage. Likely, I'm super sensitive to phase and subtle timing differences between a flat planar (ribbon and line arrays), curved planar (Martin Logan), and spherical (dynamic driver) wave launches of the direct and subsequently the indirect/reflected soundwaves.

At less than US$30k for the pair (including the active amplifiers with the analog crossovers) it's the ideal system to own even if there were no financial constraints for the purchase of monoblock amplifiers + statement loudspeakers as an "upgrade" a few years later if/when the market for US$250k+ loudspeakers (combined, US$350k+ with monoblock amps) experience a downward correction.

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The Linkwitz LX521.4 system was outstanding - no - astonishing! It was pure serendipity - I stumbled upon the demo room by chance during the last hours on the last day of Munich Show off the beaten path inside the adjacent Automobile Museum venue. I was grinning ear-to-ear when I heard the expansive and stable soundstage which discretely fleshed out all of the individual molecules of any/all performances in the correct natural spectral balance and natural 3D micro/macro positions within the soundstage.

At less than US$30k for the pair (including the active amplifiers with the analog crossovers) it's the ideal system to own even if there were no financial constraints for the purchase of monoblock amplifiers + statement loudspeakers as an "upgrade" a few years later if/when the market for US$300k+ loudspeakers experience a downward correction.

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I am a long time fan of linkwitz !
A friend has a pair and another friend has the kyron gaia .. they really are next level but waaaay more spendy https://kyronaudio.com.au/gaia.html
 
I am a long time fan of linkwitz !
A friend has a pair and another friend has the kyron gaia .. they really are next level but waaaay more spendy https://kyronaudio.com.au/gaia.html
They Kyron Gaia looks very promising. But I'm really not a fan of the MTM D'Appolito array, and it seems to be missing a rear-firing tweeter too.
 
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They Kyron Gaia looks very promising. But I'm really not a fan of the MTM D'Appolito array, and it seems to be missing a rear-firing tweeter too.
All Kyron models have a rear-firing tweeter. I quite enjoyed the Kronos when they first showed at the Munich show.
 
They Kyron Gaia looks very promising. But I'm really not a fan of the MTM D'Appolito array, and it seems to be missing a rear-firing tweeter too.
Is it a technical design issue or your experience listening to mtm that is not to your liking.. to me these have a seamless presentation.
They definitely have a rear tweeter
 
In my post regarding speaker preferences a year ago, I mentioned the following:
I'm not a fan of M-T-M D'Appolito arrays, as I can easily hear driver nulls which among other undesirable polar inconsistencies, separate music into vertical layers of horizontalized donut "rings".

This was based on many experiences of auditioning a wide variety of loudspeakers with MTM arrays. The Rockport Lyra, which is still on my list of "to audition" loudspeakers, appears to be a MTM, but is actually a 3-1/2 way design, with the top midrange driver handling the crossover transition from the bass drivers then rolling off at 500Hz, with minimal overlap with the bottom midrange driver which blends coherently with the tweeter for a more genuine point-source output. Rockport themselves have moved away from the D'Appolito array in their flagship models (ie. Arrakis, to the Lyra), possibly due to the inherent sonic shortcomings of the traditional MTM arrangement.

This 2013 review from Stereophile is a bit old, but the MTM driver cancellations (mostly driven by destructive interference between the two spaced-apart midrange drivers) often manifest themselves as non-linearities (sometimes quite extreme) in the vertical axis; see figure 7:

BTW, Stereophile unfortunately rarely publishes vertical response data of +/- 45 degrees, and instead narrowed it down to a completely useless +15* (above axis) and -10* (below axis), very likely due to speaker manufacturer protests, as the truth hurts sales. Buyer beware!
 
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In my post earlier this year, I mentioned the following:
I'm not a fan of M-T-M D'Appolito arrays, as I can easily hear driver nulls which among other undesirable polar inconsistencies, separate music into vertical layers of horizontalized donut "rings".

This was based on many experiences of actually having listened to a variety of loudspeakers with MTM arrays. The Rockport Lyra, which is still on my list of "to audition" loudspeakers, appears to be a MTM, but is actually a 3-1/2 way design, with the top midrange driver handling the crossover transition from the bass drivers then rolling off at 500Hz, with minimal overlap with the bottom midrange driver which blends coherently with the tweeter for a more genuine point-source output. Rockport themselves have moved away from the D'Appolito array in their flagship models (ie. Arrakis, to the Lyra), possibly due to the inherent sonic shortcomings of the traditional MTM arrangement.

This 2013 review from Stereophile is a bit old, but the MTM driver cancellations often manifest themselves as non-linearities (sometimes quite extreme) in the vertical axis; see figure 7:

BTW, Stereophile unfortunately rarely publishes vertical response data of +/- 45 degrees, and instead narrowed it down to a completely useless +15* (above axis) and -10* (below axis), very likely due to speaker manufacturer protests, as the truth hurts sales. Buyer beware!
Thanks for the detailed reply .. I was aware of this lobing effect but never have really tried to
"Hear" it in MTM. It certainly shows in the YG plot and is in the midrange area
In the vertical 10 degrees off axis would be well out of the listening zone and the same lobing reduces power further off axis leading to lower power floor and ceiling reflections so arguments can be made
Would be very interesting to measure the kyrons to see where they sit
 
Thanks for the detailed reply .. I was aware of this lobing effect but never have really tried to
"Hear" it in MTM. It certainly shows in the YG plot and is in the midrange area
In the vertical 10 degrees off axis would be well out of the listening zone and the same lobing reduces power further off axis leading to lower power floor and ceiling reflections so arguments can be made
Would be very interesting to measure the kyrons to see where they sit
Floor bounce cancellations are ABSOLUTELY normal - the human species have evolved to expect floor cancellations as ground-dwelling creatures. Whether it's a cello, piano, or a singing human voice, they're all ground-bound sources of "music"! Floor bounce "cancellations" are innocuous high-Q (narrow but steep) and are distance dependent and distance variable.

I believe it's one of the sensory inputs (along with visuals which are the primary sensory inputs) required by the ear-brain apparatus to compute distance, size, and specificity of the source, crudely similar to how a bat might use sonar to echo-locate, in the macro (not micro) sense. Most people are unaware that we unconsciously use subtle head tilt movements to hone into the sound sources more precisely by detecting subtle shifts in timing and tonality of both the direct and indirect sound arrivals. The "illusion" of stereo soundstaging is synthesized this way. Whereas dispersion anomalies of loudspeakers in both horizontal and vertical polar axis are computed by the ear-brain mechanism as being unnatural.

The extraordinarily uniform off-axis radiation propagated by the baffle-less Linkwitz speakers create the most genuine soundstage I've ever heard, and its cardioid pattern wave launch (above 200Hz) actually enhances the synthesis of the phantom soundstage by reducing deleterious sidewall reflections which confuse the ear-brain mechanism. Below 200Hz, the bass module also exhibits a partial cardioid pattern which significantly reduces excitation of room nodes.

The following video is rather old, but you can choose to view it in 1.5x speed to digest the information more quickly. It's Sigfried Linkwitz himself educating the audience on the topic of the importance of uniform off-axis dispersion and its role in creating an authentic and stable stereo soundstage.

 
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Excellent discussions on design and features of MSB’s Cascade DAC and 500-series amplifiers (my first choices of DAC of amps for my future system) presented by the owner/team members themselves.

 
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Excellent discussions on design and features of MSB’s Cascade DAC and 500-series amplifiers (my first choices of DAC of amps for my future system) presented by the owner/team members themselves.

AD ... if you get a chance to audition similar aries cerat gear it's worth a listen

Phil
 
My basement audio room’s reinforced concrete walls have been cast!
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The ceiling slab is actually the entrance driveway and unexpectedly slopes a bit from a low of 3.8m (left) to a high of 4.2m (right), but shouldn’t be a problem as the visual reference will be a uniformly horizontal false ceiling, targeting a height of 3.4m (11.0ft). Its 7.1m width, 10.4m length, with carefully optimized acoustic treatments will (hopefully) result in a world class listening room.

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The swimming pool protrudes down against the back wall, but will integrate well with my home office desk placed directly below.
 
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The internal dimensions of the basement listening room are shaping up!

Reinforced-concrete slab clearances
Length: 9.710m
Width: 7.100m
Height: 4.200m at the highest point on the ceiling, sloping down to 3.800m at its lowest

False ceiling heights:
center: 3.7m
perimeter: 3.15m
under pool projectile: 2.80m

Shown below:
Architect's drawings
AMROC Bolt Bonello calculations (based on slab clearances)

2024-07-24 ceiling height.png

Screenshot 2024-07-24 223245.png
 
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The above-ground structure is rising nicely; the move-in date will be sometime next Spring.
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The horizontal i-beams have been removed, giving the audio room a much cleaner look!
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Coming along very nicely!
 
A fun thing to do before any treatment is to run fixed hz low fr signals and walk the width and length to experience the nulls and peaks .. they should be perfect in a space like that.. it's very spooky
Exactly what I was thinking of doing! Projecting my voice inside the bare-walled space activated particular room resonances (room nodes) which lingered on for many seconds (which felt like "forever"). The untreated room (with bare/raw walls, ceiling, and floor) is almost a perfect reverberation chamber, LOL. A very spooky and bizarre experience, indeed.
 
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Exactly what I was thinking of doing! Projecting my voice inside the bare-walled space activated particular room resonances (room nodes) which lingered on for many seconds (which felt like "forever"). The untreated room is almost a perfect reverberation chamber, LOL. A very spooky and bizarre experience, indeed.
I have one of those but a bit smaller .. low frequency was about 1.4 seconds as I recall :)
 
Post-Munich High End show, I've narrowed my speaker choices to the following two, which are near-dipoles or dipoles, radiation patterns which I'm extremely fond of.

OLD 3 (2024-Jun):
Linkwitz LX521.4 dipole loudspeaker w/active crossovers and amplifiers
Von Schweikert Audio Ultra 9 mk2 (perhaps available in 2025?)

downgraded/temporized:
Magico M7 - anticipating costly ancillary components; challenging listening room integration; uber expensive
Rockport Lyra - remains extremely elusive, therefore unable to audition
Marten - 1st order crossovers result in undesirable phase shifts and vague off-axis soundstaging
TAD Reference 1TX - extremely prominent (overpowering?) bass, overpowering relatively narrow directivity/dispersion mid-high coax drivers
Vimberg/TIDAL - unable to audition at Munich
Vivid Moya 1 - concerns about room integration; no production plans for a smaller model, the Moya 2
Zellaton - expensive; suspicious about its non-orthodox cone tweeter's off-axis dispersion

OLD 2 (2024-Apr):
Magico M7
Marten (audition in Munich)
Rockport (Lyra - still unable to audition properly, grrr)
Von Schweikert Audio Ultra9 (mk2?) + pair of high-level input bass-management subwoofers
TAD Reference 1TX
Vimberg/TIDAL (audition in Munich)
Vivid Moya 2 (trickle-down from the M1?)
Zellaton (audition in Munich)

OLD 1 (2023-May):
Magico (upcoming M7/M8 incorporating trickle-down technologies from the M9)
Marten (audition pending)
Monitor Audio Hyphn - cliff drop off-axis propagation of high frequencies; peaky and "shouty" midrange
Rockport (Lyra - audition pending)
Von Schweikert Audio (Ultra 7 or 9 + pair of high-level input bass-management subwoofers)
TAD (co-axial drivers, ie. Reference 1-TX)
Vimberg/TIDAL (auditions pending)
Vivid (upcoming flagship model, one slot above the Giya G1 Spirit)
Zellaton (audition pending)
SPEAKER CHOICES
updated 2024-Sep

(new) Dali Kore: I first saw a static display unit during Munich 2024, motivating me to dig deeper, and was extremely impressed by Dali's design, engineering, execution, explained in great detail inside their White Paper. https://cdn.brandfolder.io/T355Y1FY/at/c4nphnn2sszcnckhwsg58j/DALI_KORE_-_White_Paper.pdf
I was finally able to audition a pair at a local dealer in an extremely sub-optimal setup (jammed up against the front wall/sidewalls driven by mid-Fi components) but was extremely impressed nevertheless! I've created a new WBF thread on the Kore loudspeakers.

(new) Dali Epikore 11: at half the price, Kore's recently introduced trickle-down technology little brother; I like the distributed array bass driver design with the upper pair of bass drivers helping to mitigate floor-bounce artifacts. The cabinet's narrower baffle enables wider off-axis mid/hi frequency dispersion than the Kore, with overall performance which belies its size/price. Dali's White Paper on the the Epikore 11 is available here:

Universally loved by reviewers, including this rave review:

(alternative) Linkwitz LX521.4 dipole loudspeaker w/active crossovers and amplifiers; loved the demo at Munich 2024, and a bargain for <US$30k

(wish list) Von Schweikert Audio Ultra 9 mk2 (perhaps available in 2026?); love their unique rear-ambient drivers and the GAIN crossover network, VSA/VSR have been my audiophile reference speakers for the past 25+ years.
Vivid Moya-2, a smaller brother to the flagship Moya-1?
Rockport Lyra, the forever elusive flagship; c'mon Rockport, where in the world can I audition a pair which is set up decently?
 
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Regarding racks and platforms, I'll likely go with a combination of HRS's EXRD (double-width) rack and Seismion's Reactio or Reactio-plus (active vibration reduction) platforms similar to the configuration in the photo below. My source components will be comprised of a two-chassis Aurender N30 music streamer, and (likely) MSB Technology's three-chassis DAC, so six platforms should be adequate.

Two such rack units placed side-by-side (for a total width of 120cm x 2, or 47" x 2) will accommodate up to 12 components or more (when stacked within individual shelves), necessary if I spread out for display peripheral components which I normally tuck away behind on the ground, such as switches, isolators, power supplies, isolation transformers, etc., and most definitely if I eventually acquire an oil-rig style TT and its associated components. :p

I will skip HRS's M3X2 isolation bases in favor of the Seismions which I believe will deliver more neutrality, albeit at a higher cost.


While the benefits of vibration isolation on sensitive components can be profound, not every component (such as power supplies) needs to be cocooned on top of a Seismion platform, so ultimately I'll let my ears guide me. Minimizing the total height will be an important objective, as I believe that any obstruction in the space between the loudspeakers (especially near the midrange drivers and tweeters) would be highly destructive to the soundstage if it's not broadband diffusive. So I may go for lower shelving options than the default 8" component spacing pillar height.

The double-width shelves on the EXRD rack will have a central pillar towards the back, but should not obstruct cables connected to the back of individual components.

HRS EXRD + Seismion.jpgWhatsApp Image 2024-09-16 at 12.33.08_ea94b0b9.jpg
 
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