McIntosh ML1 MkII loudspeaker

What was old is new again. McIntosh Laboratories has been in business long enough that they are able to bring new design thinking, materials, and construction methods to products from their extensive back catalog. Example: McIntosh's first successful loudspeaker, the ML1. The venerable Binghamton, New York, hi-fi company recently released a redesigned "Mk II" version ($12,000/pair, stands included).

In this, McIntosh is not unique; KLH, JBL, Klipsch, and other companies have rethought and reworked vintage products for the current marketplace, employing new approaches and technologies. Think of it as remastering classic hardware.

I asked McIntosh President Charlie Randall how he thought about the process of updating and reissuing classic designs. His response: "We always pick products that have been pivotal in McIntosh's history, as well as products that are timeless in performance. Obviously, we incorporate new parts and materials to bring the products up to today's standards. There is a careful balance between protecting the past and playing in the present so as not to diminish the brand."

Then and now
Ken Kessler's handsome, thorough book on McIntosh history, McIntosh—For the Love of Music, spells out the details. McIntosh made one earlier attempt to design a speaker, the three-way F100 from 1952 (footnote 1), but it was not considered a success and was quickly discontinued. After that, the company stuck to electronics until about 1970, when Roger Russell, then McIntosh's chief acoustical engineer, designed the ML1, a sealed-box, acoustic suspension, four-way loudspeaker featuring a 12" woofer. Russell's design included companion equalizers that were intended to enhance the bass performance. Russell has described his technical work in detail in his own online history of McIntosh (footnote 2).

Many but not all of the ML1 loudspeaker's features are retained in the ML1 Mk II. Like its ancestor, the ML1 Mk II is built into a sealed-cabinet acoustic suspension enclosure. The dimensions are unchanged: 26" high, 15" wide, and 13½" deep. That's bigger than a typical bookshelf speaker but much shorter than you'd expect a floorstander to be. One of the simplest, most important improvements offered with the new model are dedicated stands, which get the speakers up off the floor and rake them back, for much better on-axis behavior in most listening setups. The stands are labeled at the bottom front with a striking, diecast-aluminum McIntosh badge. Each speaker weighs 66lb, and each stand adds 19lb. Around back are two pairs of McIntosh's excellent gold-plated speaker taps, allowing for biwiring or biamping.

The exterior surfaces of both the cabinets and stands are finished in an oiled satin veneer of American Walnut. The substantial, detachable grille plates are framed with thick slices of that same walnut—solid, not veneer—held in place by powerful neodymium magnets. The louver-blind design of the earlier grilles has been replaced with a simpler, more sonically transparent stiff-mesh grille material made from a coated, web-like fabric that's said to be tough enough to afford protection from toddlers and cats.

Sturdily ensconced on twin legs, the ML1 exhibits personality, as if it was about to start trotting around the room. Some people have described the look as retro, and it certainly has that Arts and Crafts–era vibe. If you are seeking a speaker with a hi-tech, sci-fi look, you'd best look elsewhere.

Beneath the surface
Most of the changes from the earlier ML1 are under the hood. The earlier ML1 employed four drivers; now there are five. A key element common to both is a 12" woofer in its own sealed-interior enclosure. There are two 4" lower-midrange drivers—the earlier model employed a single 8". Higher frequencies are handled by a 2" soft-dome upper midrange and a 20mm (roughly 0.8") treated-titanium dome tweeter. The earlier version's paper (for the cones) and cotton (for the surrounds) have been replaced by polypropylene and rubber. The frequency range of the new speaker is specified by McIntosh as 27Hz–45kHz.

Sealed-box acoustic suspension speakers are less common today than they used to be. I asked McIntosh (footnote 3) to contrast this approach with the vented approach more often used today. "We wanted to capture as much of the original design's intentions as possible. Acoustic suspension core-design principles lie in lowering distortion through utilizing much of the very linear air spring in the sealed enclosure to control resonance. Sealed-box designs roll off at 12dB/octave below resonance. A vented design rolls off at 24dB/octave below resonance." So while a vented (bass-reflex) speaker can go lower for a given cabinet volume, the slower rolloff of a sealed box mitigates this to an extent. "At about 70% of the vent resonance frequency, the sealed system has a greater output and with a more controlled motion. That equals lower distortion."

Particularly interesting is the evolution and function of the 12" woofer. This was a key design element then, and it is now. I've never had a hi-fi loudspeaker in my house that contained a 12" woofer. When properly constructed and powered, a 12" driver can yield a visceral "oomph" that smaller drivers have trouble matching. Back in the day, engineer Roger Russell went to great lengths, including with those outboard equalizers, to find a way to drive a loudspeaker as low as 20Hz with a flat frequency response. Today, McIntosh has achieved similar behavior using what they call their "LD/HP" (Low Distortion High Performance) Magnetic Circuit Design, which is patented. As implemented in the ML1 Mk II's new 12" woofer, LD/HP reduces second and third harmonic distortion while increasing efficiency and power handling. Other developments applied to the new woofer include a rear vent through the magnetic assembly, which improves heat dissipation, and increased space under the voice-coil and spider assembly, which helps control noise. The ceramic magnet and gap shapes are modeled for long linear excursion. The voice-coil is constructed from four layers of copper. McIntosh claims transient response that rivals woofers twice the size. (That would be a very large woofer indeed.)

The ML1 Mk II's specified maximum power handling is 600W; that's a lot of power. Plus, you can rest easy in knowing that McIntosh has included self-resetting, high-current PTC fuses in the crossover network to protect the loudspeakers from damage.

The second-order crossover networks employ materials and techniques that were not available in 1970, like inductors with low DC resistance and capacitors with low equivalent series resistance. It's a four-way design—one of the most 1970s-looking things about this speaker is the proliferation of drivers on the broad front panel—with, of course, three crossover frequencies, at 180Hz, 500Hz, and 4500Hz. This combination of crossover points avoids the range in which the fundamental frequency of most vocals occurs.

Another design element that differs from the earlier version is the positioning of the upper drivers. The four in the upper part of the cabinet are placed symmetrically, mounted together on a machined aluminum plate. McIntosh claims that this results in improved imaging; I found off-axis reproduction excellent, making this a loudspeaker of choice for listeners who want to be able to enjoy their music outside the "sweet spot." McIntosh told me that the developers of the new ML1 utilized "extensive computer modeling, included on- and off-axis prediction."

Sealed enclosures are not known for sensitivity; the sensitivity rating for the ML1 Mk II is 85dB/2.83V/m, which is average. The manual recommends a minimum of 75W for amplification; McIntosh commented, "This very much depends on the average output level one wants to achieve. In a typical listening room with moderate reverberation, one should be comfortable with 200Wpc."

The stated nominal impedance is 8 ohms, which, if corroborated, would make the speaker an easy load despite the modest sensitivity. I requested and was provided with a graph of impedance behavior. There is a single peak in the low frequencies, corresponding to the woofer's resonance in the cabinet, then a mild rise to lower- and upper-midrange crossover points. The lowest point for impedance on the graph lies around 4 ohms near 50Hz. John Atkinson's measurements will reveal more.

Ready, set, listen
I have found the quality of McIntosh's shipping containers to be excellent; the ML1 Mk II was no exception. Packed in four separate boxes and quite a bit lighter than several other loudspeakers I have auditioned recently, the speakers and stands were set up in a jiffy.

A sealed cabinet is an advantage with setup, since you don't need to worry about vents interacting with room boundaries, yet jamming speakers into corners is not a good idea unless that's the designer's intention, as it is with Audio Notes and certain Klipsches. The sturdy stands come with a choice of smooth metal casters or spikes, to work with different floor types. Once the stands are sited, the speakers are easily placed on top. Once that's done, you're ready to connect wires.

Using the small wrench provided for McIntosh's excellent speaker taps made connecting a snap. It was all in the family this time, as in my Downstairs System, I currently run the McIntosh MA252 integrated amplifier, which is capable of delivering 100W into an 8 ohm load.

I view the concept of break-in with one eyebrow arched; we are crossing the line into audio voodoo here, in my opinion. However, the one component category where the idea of break-in makes most sense is with loudspeakers: The idea that moving machined parts with tight tolerances may take some time to loosen up and get in the groove seems reasonable to me. I admire my fellow audio writers who have the willpower to let things run in for days or weeks before they pay any attention to it, but I'm too impatient usually—with something new, I want to hear results right away.

Footnote 1: An interesting if random observation: Ford Motor Company's F100 was introduced the following year, in 1953.—Jim Austin

Footnote 2: See

Footnote 3: I actually asked specific people—not the whole company—but when answers came in by email and I asked who they should be attributed to, the answer was "McIntosh," so here you go.

McIntosh Laboratory Inc.
2 Chambers St.
NY 13903
(607) 723-3512

Glotz's picture

I get vintage, but.. whaaaaaat? Lol..

Provide an alternate sans wood grille as well?

Nice review Sasha. Yes, Virginia, break-in is real. So are cable performance differences. Ask your cronies!

supamark's picture

The grill actually improves the measured sound, with a chonk of wood in the middle lol.

Glotz's picture

Lol! I bet it's necessary now due to the original design parameters for the rest of the speaker.

Ortofan's picture

... upgraded parts in the crossover.

supamark's picture

A $12k standmount speaker should not be using low cost caps in its crossover. They're not even high tolerance (5%?!?! - No. Use only 1% or better in a $12k speaker).

My Dynaudio Heritage Specials cost about half of what this speaker does and uses significantly better quality parts (top of the line Mundorf caps and WBT terminals, plus the amazeballs Esotar 3 tweeter, etc). I blame the new owners at McIntosh. A private equity company now owns the brand group, so I expect them to get "Gordon Gekko'd" over the next few years and parted out. Sonus Faber is also part of the group. Same crap Sound United did to Boston Acoustics (which is now defunct). Wonder what they'd want for the brand name?

JohnnyThunder2.0's picture

would deliver so much more fidelity, musicality and finesse. Yeah, you would spend more for a similar sized box. Sadly probably over the heads of most potential purchasers of this speaker. But Macintosh is an American lifestyle brand so you get what you get: a Ford F150 of a speaker. PS - of the new versions of old American brands, I think Klipsch seems to be the most authentic though one of those new JBLs was admittedly a lot of fun to listen to for hard rock.

MatthewT's picture

With those stupid LED's under the tubes.

supamark's picture

And the JBL's I want to hear are the 4367's that were reviewed here a couple years ago - 15" + horn and measures great.

Ortofan's picture

... about double the price of the ML1 MK II, for the same $12K one could buy a pair of Harbeth SHL5plus XD speakers, AND a pair of REL Classic 99 subwoofers - which have a 12" driver (and a 450W amplifier).
"Fidelity, musicality and finesse" plus deep, powerful bass response.

JohnnyThunder2.0's picture

While a 12" woofer is going to move a lot of air and shake the foundations in a way other speakers physcally cannot, I would agree 1000% that the Harbeth/REL combo you described would be way more musical and beautiful sounding. Of course, I haven't heard these behemoths but they get disqualified from my world immediately without a silk or sophisticated soft dome tweeter like the Harbeths. I have heard the Harbeths in demo and it was one of the few times I felt some regret over the speakers I had purchased a few months before. Beautiful ripe bass and smooth sweet highs. Maybe they wouldn't play Van Halen or Wu-Tang Clan as well as these Macintosh speakers but in almost everything else I bet there would be no comparison.

MatthewT's picture

I'm sure it's just me, but I do not get the love for Mac gear.

georgehifi's picture

They just love the colour blue, but where is it here???
And yes those Bennic caps are bottom of the barrel.
Cheers George

supamark's picture

the love for the older built like a freakin' tank Mac's that last for decades, but not the newer built to a price point stuff. They were aquired by a private equity firm in 2022, and quality is never in their equations.

Glotz's picture

Do not get how they could be so out of of touch with audiophiles and the generally informed public.

And to agree to a review when there are some glaring issues like parts quality for this price point. I would still think PE firms know their market. Pfft.

PeterG's picture

I love my C22/MC275 amps, but these are a stretch. At $12,000, there's some very tough competition, and so much about these seems like a marketing grab. In addition to the specifics mentioned above, we should add the bases--do those look well-engineered for rigidity. isolation, etc to you? I suppose I would listen if I was already in the store and the dealer insisted...

David Harper's picture

Truer words were never spoken. Dynamic cones and domes in a wooden box.
12K/pair. Perfect match for the 28K vacuum tube amp in the next review.Back to the future. Audiophilia is truly a strange thing.
Value/performance inversely proportional to price. But I still read these reviews. The subjective descriptions of sound are mind-bending. I marvel at the ability of the writer to describe the sound of an amp or a speaker in terms that defy any rational real-world experience of home audio. But maybe imagination is what's important. Maybe I lack imagination.

supamark's picture

You whine about the ultra expensive stuff then ignore the $300 streaming integrated (aka the new jack receiver) review posted yesterday.

As far as the subjective descriptions; perhaps they, like myself, have synesthesia. JCA has said he has it, and JVS' descriptions sound like he has it - he once described a golden glow within the sound that I've literally experienced myself. It wouldn't surprise me if HR and KM have it too. When I say something sounds grey, I literally see the color grey overlaid on the sound (phase issues in the treble cause this for me). If I say it sounds like stucco, I literally see/feel that texture of smearing when I hear the sound (DSD, don't know why, and always white stucco). The brain is weird and wonderful, and they're all different.

Synesthesia, at least for me, is like a cheat code for writing about sound since I literally have both visual and tactile sensations along with it. Unfortunately, I also have misophonia with a few sounds. Like the sound of someone licking paper, especially construction paper... aagh, just thinking about it squicks me out hard. When I was reviewing equipment, once I got a handle on the sound the writing was usually quick and easy.

Thinking your experience of the world is the same as anyone else's is the height of arrogance. If we were all the same humanity would have gone extinct long ago.

David Harper's picture

Every now and then I'm powerless to resist my compulsion to respond.
I'm working on it.

supamark's picture

also, these do not meet the price to performance ratio required of $12,000 real US Dollar retail speakers, on this we do agree.

ok's picture

(high, low, hard, soft, sweet, cold etc) are actually metaphorical. There must be a good reason for that, but it eludes me thus far.

supamark's picture

When I say something sounds "grey", such as Outkast's otherwise excellent song "ATLiens," I literally mean I see the color grey while listening, with a roughly 90 to 95 percent transparency. It's not a metaphor, it's literal and it's how I hear high frequency phase issues. A doorbell literally shot squiggly red geometric shapes out towards me once. luckily, my visual synesthesia is very rarely that pronounced. Texture/tactile is a bit stronger for me.

Bruce Swedien has said it can be a curse to have synesthesia (he had it), because it can be distracting while trying to mix a record, such as Off the Wall or Thriller. He also used it as a tool, saying he knew the tonal balance of a song mix was right when it sounded golden. As in he saw a golden hue while listening. It's half the reason recording studios are often dimly lit. Rock-n-roll is the other half (metaphorically, wink wink, nudge nudge, know what I mean). 5 to 15 percent of the population has synesthesia, but anecdotally it's higher among sound professionals (sound is more interesting when you can see/feel/taste/smell it).

Woody, I assume is more mundane - it sounds like the resonance frequency of a log. I occasionally feel a woody texture, but it's very rare. Sometimes what people call woody sounds brown of various shades to me, but not always. IT IS NOT THE BROWN NOTE. "Woody" is around 300 to 500 Hertz.

High/low; frequency? so it's a grouping of numerical values.

warm/cool - metaphor, for me at least

hard - literal for me, usually really bad high frequency phase issues. or the NAD M23 into large Focal speakers (class D phase issues into very bright beryllium tweeter speakers). It literally sounded/felt like the edge of an off-white cultured marble countertop was hitting me regardless of volume. Hard and unpleasant. And a very bad pairing of amp and speaker. This may explain why I prefer soft dome tweeters (resonance behavior).

soft - can be literal for me, also metaphorical

sweet - metaphor for me

funambulistic's picture

Very interesting supamark! It is a helpful, if not trippy, tool for me as well. I see "sound bubbles" if the system is set up well and capable of producing them. I recently had the pleasure to listen to two systems belonging to members of a local audio club. They were relatively equal with regard to price (i.e., "if you need to ask" expensive). One produced said bubbles, the other did not. You can guess which one I preferred.

I also "see" different materials, especially metals but sometimes fabrics, mostly in the treble region. The "whiter" the material, the less I like it. If I see aluminium or steel (separate from the actual tweeter material - it could be a metal or fabric dome) I run for the hills!

supamark's picture

In a review I once described a DAC as sounding like galvanized metal; scratched, scuffed, and bare that's been sitting out in the blistering Central Texas sun for years. It was the Schiit Modi Uber 2 delta/sigma DAC, and annoyingly my editor cut it from the piece. He works for Magico now, and I'm retired from reviewing (it made me not want to listen to music, it became work). I'm all better now lol.

About Lyle Lovett's "She's Already Made up her Mind" from the same review, "The bass was deep, vibrant, and textured like corduroy through the Modi Multibit; through the Uber 2 the corduroy was worn, faded, a little threadbare." That one stayed in.

About "I've Been to Memphis," "When the bass guitar enters just before Lovett starts singing, it sounded like chocolate-cake batter being poured into a pan as wide as the soundstage." This one also stayed in.

Joshua Judges Ruth is my favorite test record, because not only is the sound amazing with lots of little "tells" for sound quality, but the music is actually really good too. If you can write well and listen critically, synesthesia makes audio equipment reviewing pretty easy (they're ALL done to a template - intro story, tech stuff, what it sounds like/comparisons, conclusion in Stereophile and Soundstage! for example). Coming up with an interesting intro that relates to the item under review is the only hard part.

The bubbles sound really cool, mine happens with color + texture: grey for treble phase issues, metallic like I described above for horrible phase issues (I think we're hearing the same thing there). Golden usually means what the bubbles mean to you. Too much low mid/upper bass (~250 to 600 Hz) sounds various shades of brown, with maybe some wood texture. Distortion tends to be white and spikey. I find it fascinating how synesthesia manifests differently in everyone.

I recently listened to the KEF Blade II Meta (vs Dynaudio Confidence 30), and it sounded like a visualization of a spacetime gravity well into the tweeter. Like I saw actual dark fabric being pulled away from me, and tugging on me, into the tweeter. It was really f'ing weird.

Kal Rubinson's picture

"I recently listened to the KEF Blade II Meta (vs Dynaudio Confidence 30), and it sounded like a visualization of a spacetime gravity well into the tweeter. Like I saw actual dark fabric being pulled away from me, and tugging on me, into the tweeter. It was really f'ing weird."

Wow! I am working hard on that one.

Archimago's picture

Interesting descriptions and I'm sure in some areas can be very useful - like writing subjective reviews where the creative wording can be novel I guess.

I suspect most of us are simply glad we don't have such experiences though which can be distracting. People I have met who have synesthesia describe idiosyncratic reactions that are not particularly well correlated to "good" or "bad" characteristics, just "different" or unique for them.

ok's picture

..since I'm not familiar with synesthetic experiences. It still never fails to amaze me that there is no literal vocabulary peculiar to sonic qualities and one is forced to rely on various metaphors; it also makes it extremely difficult for one to communicate one's inner perception of sound/music in a meaningful and useful way - hence the usual argument "I don't (think I) hear it, so you don't hear it either!"

scottsol's picture

These speakers in no way reflect poorly on the current owner of McIntosh. Rather than indicate a changed approach for the company, they perfectly align with the market position that Mc speakers have always filled.

laxr5rs's picture

I don't understand the idea of adding drivers... if the response already bad.