M&K Sound S150/S150t THX Ultra Speaker System Review

Build Quality
PRICE $10,595 (7-piece system as tested)

Very accurate sound
Excellent dynamics
Great for movies
S150 speaker terminals don't accept standard banana plugs

M&K Sound's revamp of its long- standing THX certified line delivers audible improvements over the original speakers.

It was a sad day for home theater fans when M&K Sound exited the speaker-building business in 2007. Fortunately, a group of investors and former managers bought that company's assets and created a new venture called MK Sound. To celebrate the company's 40-year anniversary in 2013, the team decided to bring back the legendary M&K Sound company name, along with the original Miller&Kreisel brand. Today, top models from M&K Sound all carry the Miller&Kreisel name and I've had the opportunity to review a number of the company's offerings, including the X12 Subwoofer and the S300 sub/satellite system. The latest offering to come my way from M&K Sound is the all-new Miller&Kreisel S150 Series, consisting of the S150 LCR speaker ($1,799 each) and the S150T surround ($2,599 pair).

Familiarity Doesn't Breed Contempt
I've used a seven-channel M&K S150 speaker system consisting of three S150 LCRs across the front along with four S150T surround speakers in my theater for the past 15 years. I've always wanted to upgrade to an M&K Sound subwoofer, although cash has been tight over the past few years with two kids in college. Regardless, I've happily managed with a quartet of subwoofers that includes an SVS PC-Ultra, HSU 15H-MK2, and a pair of JL Audio D110s, all run through a MiniDSP configured to provide a flat in-room frequency response.

The original M&K S150 was regarded as one of the most accurate speakers on the market and served as a reference monitor for many music and movie soundtrack production facilities. The line was revised a couple of years after the purchase and rebranded as the S150 MKII. But as with all products over time, a further update was in order. Can this new version of the legendary studio monitor carry on the company's legacy?


Nearly three months elapsed from the moment I was asked to write this review to the day that speakers finally showed up at my house, so when the boxes arrived I couldn't wait to get them opened. These are beautiful speakers—a definite aesthetic improvement over my legacy S150s. For starters, the new cabinets are a smooth gloss black as opposed to a textured satin, so when dust settles on them, they are easier to clean. Granted, the glossy finish is prone to fingerprints, but that's why M&K Sound includes a pair of white gloves in every box! My only gripe is that the S150's speaker terminals don't accept standard banana plugs. While that's not a big deal— most users rarely unhook their speakers—those of us with a revolving door for review products prefer the ease of plug-and-play.

The original S150 line had dedicated right, center (in my case, angled center), and left speakers and each cabinet was constructed differently. The left/right speakers were toed in with their outside edge longer than the inside to create a 45-degree angle. M&K's center speaker was designed the same way, but with a slightly longer top or bottom depending on if the speaker was placed above or below your screen. The original speakers, which conformed rigidly to THX specifications, also featured foam pads mounted between their three tweeters to make them as vertically directional as possible.

Although still THX certified, the new S150 is a different design than its predecessor. Each box has the same dimensions, measuring 10.4 x 12.5 x 12.2 inches (WxHxD). That change likely saves manufacturing costs, and the toe-in effect can still be carried out by angling the speaker to ensure proper placement. Gone are the foam pads between the tweeters: MK Sound has re-designed the wave guide in the tweeter faceplate to provide ideal focus and integration both when the S150 is used as a nearfield monitor (closer than 10 feet from the listening position) or installed at longer distances.


The S150 features two 5.25-inch fiberglass bass/midrange drivers and three 1.1-inch Danish-designed (from ScanSpeak) fabric dome tweeters. The Phased-Focused crossover was always M&K's (and now the new M&K's) secret sauce in that it has been critically tuned through psychoacoustic and complex computer time-domain analysis to achieve a uniform timbre balance throughout the listening room. This improves the three-dimensional response and provides a reference listening experience from virtually any position. (If you decide to audition the new S150s, be sure to move around the room to experience that effect since most speakers don't sound nearly as good when you move outside the center sweet spot.) Like its predecessor, the new S150 has a 4-ohm impedance and M&K Sound recommends using between 25 watts and 500 watts of amplification. The more amp power the better—for my evaluation, I used a seven-channel ATI AT527NC (another S&V Top Pick) amp rated at 200 watts per channel.

M&K Sound
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DolopT's picture

But too expensive and out of reach for most people. Maybe M&K Sound should focus on making affordable products for audiophiles and home theater enthusiasts who can't afford speaker systems in the thousands of dollars.

dommyluc's picture

Why, surely you jest!. I am so glad these speakers have been released, since they are the perfect match for my Sony DMP-Z1 "aspirational" $8000 digital music player. I finally have a music system to put in my guest bathroom. Now please excuse me while I go out to the kitchen and apply gold leaf to the corn flakes I am going to have for breakfast.
But to be serious: I know that a lot of "bargain" speakers out there are absolute junk, but there are some good brands that put out great products at an great price. Maybe they aren't M7K or Def Tech or Golden Ear, but they are high-performing and affordable to the average person. I just wish S&V would sometimes have some reviews of bargain speaker systems just to see how they compare with some of the bigger names. Not all speakers under $500 are put together with cardboard and used bubble gum.

Al Griffin's picture
DolopT's picture

And Jamo has the right idea. And I'm sure there are other speaker manufactures who are picking up on the more affordable speaker system trend.

DolopT's picture

To me a more doable audio/home theater speaker system price is a maximum cost limit of $2000. So it doesn't have to be $500 or under to be considered a bargain. Just make a fantastic speaker system that's more attainable for the average moderate income person.

dacaudio's picture

There are in fact less expensive options available from M&K that are built with same performance philosophy. There are systems that can be had for half the price of the 150 system and even less.