25 years on and still going strong, the legendary S150 just keeps getting better 5 Stars

It was telling that Miller & Kreisel opted to place the Lucasfilm THX brand logo above its own on the front grille badge of the S150 series speakers when introduced back in 1995. Owner and chief engineer Ken Kreisel had wholeheartedly embraced the THX philosophy of how to reproduce film sound accurately in the home, to the point that he was happy to share top billing with the audio arm of the Star Wars factory. It was also something of a boon to the design team at Skywalker Ranch that this medium-sized California speaker company – whose groundbreaking work alone had cemented the satellite/subwoofer relationship as virtually indispensable for home theater – felt that the sonic qualities of THX should, in turn, become central to M&K’s core strategy.

And so it is after a quarter of a century of the existence of these iconic cuboid speakers that M&K is releasing an exclusive 25th Anniversary Limited Edition of the set, but sold ostensibly as a stereo pair, perhaps to celebrate the sometimes overlooked musicality of the legendary line. Even though it is some time since Ken Kreisel relinquished control of the company, which itself relocated from the US to Denmark, the new ownership team is rightfully proud of the extraordinary legacy of which they are now custodians. The M&K S150 satellites (combined with various versions of the company’s subwoofers) have been adopted by all the major film studios at one point or another for editing, mastering and monitoring of audio, both in production and post-production settings. Famously, Lucasfilm Ltd. deployed M&K speakers for the entire audio workflow of the Star Wars: Episodes I – III films, and many of the Blu-ray discs we enjoy at home have earned their sonic seal of approval after being reviewed on this reference platform. Consequently, if you want to know literally “what the director intended”, you could do a lot worse than invest in a set of the S150s.

Design and Features

The Limited Edition S150s have eschewed the classic black satin finish of the line in favor of a more living room-friendly “space gray” coating with an attractive silver cloth grille, which conveniently magnetically attaches to the speaker front. With only 250 units of the new speaker being produced, the lucky owners will be treated to a silver plaque on each featuring the unique number identification in the sequence, as well as newly designed crossover components by Jantzen. Although carrying the signature audio properties of the existing S150 (MKII), M&K boasts that this exclusive edition sports a bi-wiring/bi-amped capability with dual binding posts and connecting jumper strips included, a clear nod to more audiophile-oriented customers.

The enduring appeal of M&K’s S150 speakers is in no small part due to their classic design and, while perhaps not the prettiest speakers in hi-fi history, have certainly always promoted function over form, and are compact and discreet enough to allow them endless placement flexibility, particularly in a dedicated AV room. It is testament to the efficacy of both the original S150 speaker design and uncolored performance, harking back to 1995, that the look and key characteristics have remained essentially the same, even though materials and manufacturing methods have evolved over time. Many will recognize the classic vertical arrangement of the two 5.25-inch now-fiberglass mid-range drivers complemented by three 1.1-inch soft fabric dome tweeters, the latter responsible for the focused vertical dispersion qualities lending to improved dialogue intelligibility and front soundstage effects placement for movie playback. Those last specifications are required of the speakers’ THX Ultra2 certification along with their capability of achieving reference level cinema audio in a room of at least 3,000 cubic feet.
The dimensions of the Anniversary S150 are also common to earlier versions with a 12.5-inch height, 10.4-inch width and 12.2-inch depth, while the unit weighs in at a manageable 25.4lbs. The speaker retains a 92 dB sensitivity and a 4-ohm impedance with connected amplifier power recommended to accommodate a range of 25 to 500W. My personal experience with both former and current iterations of the S150 with its 4-ohm load is that it is a speaker that likes to be driven hard, and responds particularly well to audio dynamics and transients with amplifiers rated at 150W and above. Frequency response is measured from 75 Hz to 20KHz (+/- 3dB), so a subwoofer is recommended to reproduce the bottom end.

Whether opting to use the Anniversary set as a stereo pair or incorporating them into a fully-fledged immersive system for movies and TV, owners should consider using S150T timbre-matched tripoles as surrounds (which can also be wired as dipoles or as effective direct radiators) if you intend to build out a home theater. However, it is worth noting that in many professional mixing suites, the passive S150 or its active powered sister, the MPS2520P, is often used in all separate channel locations for surround mixing duties.

In Use and Performance

For the purposes of this review, I inserted the Anniversary pair into my existing home theater layout and M&K provided me with one of its own X10 subwoofers to handle low frequencies. Power amplification was provided by my trusty Parasound HCA- series models and the preamp used was a Lyngdorf MP-60 with RoomPerfect calibration. However, I treated the speakers mostly as a stereo pair with CD music sources, but also took the opportunity to A/B the new S150s with my own S150s, still going strong 22 years later!

M&K has continuously improved performance of the S150 monitor through its MKII phase (post company ownership change) and now this Anniversary edition. The original S150s were certainly no slouches, but on offer here is yet more articulation at the top end and a notably more incisive depth of field. On the Chandos recording of the opera Dido & Aeneas, Sarah Connolly’s mezzo-soprano voice on the aria “Ah! Belinda” is exquisitely rendered with piercing high notes and gentle vibrato, all underscored by a full-bodied harpsicord whose individual identifiable strings dip in and out with pleasing but varying intensity. There is also a seemingly broader soundstage here with pinpoint imaging. The “Sancte Deus” on The Tallis Scholars Sing Thomas Tallis (2CD Gimell label) precision-places the sections of the choir in the horizontal plain while the echo in the ceiling of the Merton College Chapel forces the listener to look upwards.

The S150s and X10 sub exhibit a stunningly seamless fusion between bass and robust midrange, which is illustrated by the Yes track “Fortune Seller” on the Open Your Eyes album. While Alan White’s tight drums strike with impulsive energy, the syncopated and strumming guitar is periodically immersed in an onslaught of chest-splitting and thunderous sustained bass notes. This stuff goes right to your core and is ultimately what M&K is all about.

Of couse no set of S150s can be auditioned without giving them a run for their money on some Blu-ray movie content. Having slotted the new pair in with my multi-channel system (while using an original S150 as a center speaker), I noticed a distinct enhancement in dynamic range over the old pair. The tidal storm sequence from Aquaman (2018) where the massive wave unleashes hell on the New England coast and the first frenetic motor race in Ready Player One (2018) exhibited unrelenting power. Even when collapsing the source down to a 2.1 output, the S150s still prove they are nothing short of fluent in the language of film, and can deliver home-demolishing effects and music in spades.

Conclusion

If you want to grab a piece of history and order a pair (or more) of these stylish 25th Anniversary Limited Edition silver speakers, you certainly will not regret the decision based on their performance, even if the color scheme does not quite suit your environment. While M&K is now under Danish ownership, the S150 speakers are still unmistakably American, utterly suited to the bombast and hyperbole of the Hollywood movie blockbuster, while also being enticingly accurate and restrained when needed. Some buyers may want to venture up the price ladder to the lofty heights of a Wisdom or JBL reference system for their home theater, but the reality is that you will have to spend a lot more. Others might want to stick to their tried-and-tested B&Ws, KEFs or Klipsches, as some believe the neutrality and flat frequency response of the M&Ks is not for them. But M&K is within that just-about-affordable range (at $4,200 per Anniversary pair) where you are genuinely getting the performance you pay for, as well as an unwavering endorsement from the pro audio community. Frankly, even 25 years on from the S150’s inception, whether you are selecting a system for movies, TV or stereo music, once you get hooked on M&K, you might find it forever difficult to walk away.

Home Theater Forum was thrilled to be asked by M&K to produce the very first industry review of the S150 25th Anniversary Limited Edition speakers. For enquiries, please contact M&K distributors in your country or area listed at the link here.

 

 

 

 

 

 

 

 

 

 

 

Published by

Martin Dew

editor

Carlo Medina

Senior HTF Member
Joined
Oct 31, 1997
Messages
12,026
Man I remember back in the 90s when I was first getting into home theater but had 1/5 of the disposable income I have now...I lusted after M&Ks back then. And this model specifically.
 
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KEN KREISEL

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Ken Kreisel
Martin, congratulations on your excellent article which I enjoyed reading. I think it is a testament to the original S150THX design that the THX PM3 USA made Miller & Kreisel Professional MPS-2510THX and the USA made M&K THX PM3 powered MPS-2510P/PK pro versions (with all production ending in 2007) of the S-150THX are still being used by top studios and engineers around the world to make their most important mixing and sound design decisions.

I have one small technical comment to help eliminate any confusion regarding bi-wiring versus bi-amping as mentioned in your article. Bi-wiring and Bi-amping are completely different. Bi-wiring is when you provide (on a passive speaker with passive crossovers) two pairs of speaker input terminals (with jumpers between them when using a single amp), one pair feeds the passive bass/midrange crossover (low-pass filter) and the other pair feeds the passive high-pass or tweeter crossover, usually done with two full-range amplifiers for best results. The advantages of bi-wiring versus "single" wiring are complex regarding the sonic advantages of relieving a single pair of speaker wires from carrying both the low frequency and high frequency signals from your amplifier to the speakers (the sonic benefits depend in large part on what type and length of speaker wire is being used from the amp to the speaker). There is also a sonic advantage for the amplifiers as typically in a bi-wiring situation the speaker impedance continually rises higher per octave outside the usable bandwidth of the passive low-pass and the passive high-pass crossover networks.

Bi-amping has all the advantages mentioned above but eliminates the passive crossovers altogether with a carefully designed complementary electronic crossover filter feeding the bass/midrange amp connected directly to the bass/midrange drivers and with a carefully designed complementary electronic crossover filter feeding the tweeter amp connected directly to the tweeters with no passive components in-between. The use of an electronic crossover and connecting the amps directly to the drivers can provide significant sonic improvements which the studios learned years ago.

The bottom line (no pun intended) is you really cannot use bi-wiring inputs (which still have the passive crossovers inline with the drivers) to accomplish the sonic benefits of true bi-amping. You need a switch or a multiple set of speaker input terminals (beyond four for bi-wiring) and multiple jumpers to bypass the passive speaker crossovers.

KEN
 
Last edited:

Martin Dew

HTF News Editor
Joined
Nov 1, 2017
Messages
816
Location
United Kingdom
Real Name
Martin Dew
Martin, congratulations on your excellent article which I enjoyed reading. I think it is a testament to the original S150THX design that the THX PM3 USA made Miller & Kreisel Professional MPS-2510THX and the USA made M&K THX PM3 powered MPS-2510P/PK pro versions (with all production ending in 2007) of the S-150THX are still being used by top studios and engineers around the world to make their most important mixing and sound design decisions.

I have one small technical comment to help eliminate any confusion regarding bi-wiring versus bi-amping as mentioned in your article. Bi-wiring and Bi-amping are completely different. Bi-wiring is when you provide (on a passive speaker with passive crossovers) two pairs of speaker input terminals (with jumpers between them when using a single amp), one pair feeds the passive bass/midrange crossover (low-pass filter) and the other pair feeds the passive high-pass or tweeter crossover, usually done with two full-range amplifiers for best results. The advantages of bi-wiring versus "single" wiring are complex regarding the sonic advantages of relieving a single pair of speaker wires from carrying both the low frequency and high frequency signals from your amplifier to the speakers (the sonic benefits depend in large part on what type and length of speaker wire is being used from the amp to the speaker). There is also a sonic advantage for the amplifiers as typically in a bi-wiring situation the speaker impedance continually rises higher per octave outside the usable bandwidth of the passive low-pass and the passive high-pass crossover networks.

Bi-amping has all the advantages mentioned above but eliminates the passive crossovers altogether with a carefully designed complementary electronic crossover filter feeding the bass/midrange amp connected directly to the bass/midrange drivers and with a carefully designed complementary electronic crossover filter feeding the tweeter amp connected directly to the tweeters with no passive components in-between. The use of an electronic crossover and connecting the amps directly to the drivers can provide significant sonic improvements which the studios learned years ago.

The bottom line (no pun intended) is you really cannot use bi-wiring inputs (which still have the passive crossovers inline with the drivers) to accomplish the sonic benefits of true bi-amping. You need a switch or a multiple set of speaker input terminals (beyond four for bi-wiring) and multiple jumpers to bypass the passive speaker crossovers.

KEN
Thanks for your invaluable input particularly concerning bi-amping, Ken, and great to hear from you. It's also been sometime since PM3 was discussed in the mainstream, but I think it's great to remind people of some of this indispensable history, and the extraordinary contribution M&K has made - and still makes - to the entire movie post-production and presentation ecosystem.