Marten Parker Trio Diamond Edition loudspeaker

2020 may not have been a year to celebrate, but there were some housebound highlights. For example, after I had finished with the measurements to accompany Michael Fremer's review of the Marten Oscar Duo in the November 2020 issue, I set up these Swedish two-way standmounts in my own listening room. Yes, the measured performance was excellent, but I was not expecting how much I would enjoy the sound of the Oscar Duos.

At $6995/pair, this is not an inexpensive speaker, but it rivaled the stereo imaging produced by my reference KEF LS50, played louder than the diminutive KEF without strain, and offered another octave of low frequencies. As MF concluded in his review: "Designer Leif Olofsson has threaded the needle, producing a small speaker that can produce prodigious bass (or at least bass that sounds prodigious) with composure at relatively high SPLs, without muddying up the midrange."


The Oscar Duos went back to the distributor last October, but as the new year dawned, Marten's new Parker Trio tower loudspeakers ($19,990/pair) arrived chez moi. I unpacked the Trios, set them up, experimented with positioning, listened a while, then packed them up again. It turned out that the stainless steel outrigger bases didn't have the correct-sized holes tapped into them for the mandatory Marten Isolators. Rather than replace the outriggers, Marten decided instead to send me the "Diamond Edition" version of the Parker Trio. This considerably more expensive version—$36,990/ pair—replaces the regular Trio's ceramic-dome tweeter with one that uses a dome formed from pure diamond—presumably vapor-deposited—higher-quality crossover components, improved cable terminals, and Jorma's top-of-the-range Statement internal cabling.

On with the show.

The Parker Trio Diamond
Like all of Marten's speaker lines, the Trio pays homage to a legendary jazz musician, in this case Charlie Parker. This is an elegant-looking tower, standing 45" high on its two chromed stainless steel outrigger bases with the Isolators installed. The enclosure tapers from its back to the front and is constructed from a proprietary, self-damped, laminated material that Marten calls "M-Board." The review samples were hand-finished in a matte walnut veneer.


The Parker Trio is a "2.5-way" design, with the lower of the two 7.5" woofers rolling off earlier than the upper one. The latter crosses over to the 1" diamond-dome tweeter at 2.2kHz using Marten's "Multi-Slope" crossover technology. The tweeter sits behind a mesh grille in a chromed stainless steel sub-baffle. Below it are the two woofers, mounted vertically inline and covered with metal-mesh grilles. Engineered by Marten's Leif Olofsson, these use ceramic cones and substantial half-roll rubber surrounds. The woofers are modestly claimed by Marten to be "superior to any similar drivers currently available, at any price." Reflex loading is provided by two 9" aluminum-diaphragm passive radiators mounted on the rear of the cabinet, these also covered with mesh grilles. Electrical connection is via a single pair of chromed binding posts at the base of the rear panel.


Marten's IsoPuck feet are designed by IsoAcoustics and incorporate a compliant layer that, in combination with the speaker's mass, acts as a low-pass filter to absorb higher-frequency noise in the enclosure and prevent it from being transmitted to the floor. Jim Austin discussed how the IsoAcoustics feet work in October 2020 and was impressed by the improvement they gave with a pair of Revel Ultima Salon2 speakers.


Setup & system
Marten includes a CD with a sweep tone to break in the Parker Trios. The hardbound manual says to play this track on repeat for at least 24 hours before experimenting with placement and warns that the loudspeakers won't sound their best for another 200 hours of playing music! Fortunately, and unlike the first pair of Parker Trios, the Diamond Edition speakers had been fully broken in before I received them. Nevertheless, there was a slightly lean quality to the lower midrange that gradually dissipated over the first week of using the Martens for noncritical listening.

I initially placed the Martens where the Sonus Faber Lumina IIIs I reviewed in the April issue had worked well in my slightly asymmetrical room. Though they are reflex-loaded towers, for their low frequencies to be fully developed, the Sonus Fabers needed to be placed closer to the wall behind them than I could manage in my room. (The two steps up to the vestibule behind the right-hand speaker don't allow me to move speakers any closer.) The Martens, however, offered low-frequency weight and extension in these positions, and I didn't need to experiment very much with placement.

Each speaker's front baffle ended up 77" from the wall behind it and 142" from the listening position. The woofers of the left-hand Trio Diamond were 35" from the LPs that line the nearest sidewall; the right-hand speaker's woofers were 47" from the bookshelves that line its sidewall. Even though I had toed in the Trios to the listening position, the sound was a little on the sweet side unless I sat bolt upright. When I sit in my listening chair, my ears are 36" from the floor, which is significantly below the Trio Diamonds' tweeters, which, with the speakers sitting on the outriggers and Isolators, were 42" high. I therefore placed ½"-thick, circular aluminum plates under the rear Isolators, which tilted the speakers forward a little so that I could just see along the sloped top of each enclosure. This brought the Martens' top octave into an optimal balance with the mid-treble region.


The music source was my Roon Nucleus+ powered by an HDPlex linear power supply loaned to me by Jason Victor Serinus (a worthwhile upgrade, I have found). One of two DACs—the MBL N31 or the PS Audio DirectStream—was fed audio data over my network. Amplification was the Pass Labs XP-32 preamplifier that I reviewed in the March 2021 issue and a pair of Parasound Halo JC 1+ monoblocks.


As always, before I used music for my critical auditioning of the Parker Trio Diamonds, I listened to the test tone files I created for my Editor's Choice CD (Stereophile STPH016-2). The dual-mono pink noise track sounded smooth, and its image was appropriately narrow and stable, with no "splashing" to the sides at any frequency. The Trio Diamonds reproduced the 1/3-octave warble tones on Editor's Choice with good power down to the 25Hz band, with the 32Hz warble boosted by the lowest room mode. The 20Hz warble was just audible at my usual listening level. The half-step–spaced tonebursts on Editor's Choice spoke cleanly and evenly down to 32Hz, the frequency of the lowest one. Listening to the enclosure with a stethoscope while these tonebursts played, I could hear some low-level liveliness between 500Hz and 1kHz. I could also hear a faint metallic ringing when I rapped the sidewalls with my knuckles. As I mention in the "Measurements" sidebar, this turned out to be coming from the metal-mesh grilles.

Test tones and knuckle raps are all very well, but it's the music a speaker makes that matters.

US distributor: VANA Ltd.
Nesconset, New York
(631) 960-5242

JRT's picture

I suggest (edit: I removed my erroneous suggestion).

John Atkinson's picture
Fixed. Thanks for the eagle eyes.

John Atkinson
Technical Editor, Stereophile

JRT's picture

It was intended as constructive criticism.

Keep up the good work.

MZKM's picture

in a $37,000 speaker. Doesn’t appear to be from a cabinet vibration, is it from the passive radiators?

And excuse me asking, but if the speaker is on a wheeled dolly, why can’t you fully rotate it to measure +/-90°? I couldn’t understand the explanation.

Looks like the voiced it well by adding a dip at 3.2Hz to combat the wide off-axis dispersion.

The bookshelf Duo measured around it’s stated sensitivity, so odd that this is so much lower than spec and barely higher than the bookshelf, the tweeter (BD 25-6-258?) is likely not the limiting factor.

JRT's picture

I suspect that is an internal modal resonance, a standing wave. The apparent path length is a little longer that the internal height because the path includes delays and detours around internal bracing, woofer chassis, suspension and motor structures, passive radiator chassis and suspension structures, etc.

Speed of sound is oft quoted at 68 degrees Fahrenheit at approximately 343_m/s, and is 344 at 71, 345 at 74, 346 at 77, and is primarily dependent on air temperature. Air temps inside the enclosure will be warmer than room air while the loudspeaker is operating.

(343)/(140*2)= 1.225 meters
(344)/(140*2)= 1.229 meters
(345)/(140*2)= 1.232 meters
(346)/(140*2)= 1.236 meters

You can see some associated resonance in the passive radiator nearfield response, and more resonances an octave higher. The second order resonance is not showing in the impedance curve, perhaps because the geometry is not imparting a pressure node on the woofers where it would feed through the motor and be reflected in the impedance Though the lower woofer does appear as though it should be near a pressure node, unseen internal structures may be dictating something else.

You won't see that in a PR loaded subwoofer where internal paths are small relative to wavelength. But you will see it where PRs are utilized to load midwoofers operating at higher frequencies, shorter wavelengths (shorter than subwoofer wavelegths) in the taller enclosed air volume of a floor standing loudspeaker of a design lacking internal damping located in or near the velocity node positions of the internal modal resonances of the enclosure. Suitable damping is key, essentially using internal airflow resistance in those velocity nodes, effective at the frequencies of interest, but almost invisible at lower frequencies nearer the PR tuning. An example would be some SAE F13 sheepswool techical felt (maybe in combination with some Roxul Rockboard 80) sandwiched between a closely spaced pair of windowed shelf braces and some grill mesh or perforated steel for added support located at roughly 1/3 of the internal height where it would damp fundamental and second order standing waves in that path.

John Atkinson's picture
MZKM wrote:
excuse me asking, but if the speaker is on a wheeled dolly, why can’t you fully rotate it to measure +/-90°? I couldn’t understand the explanation.

The problem stems from the fact that at angles greater than 45 degrees, there were reflections from nearby surfaces in my listening room that compromised the measurement.

John Atkinson
Technical Editor, Stereophile

noamgeller's picture

Dear John Atkinson, at the first paragraph you wrote "at 6990$ those speakers aren't inexpensive..." and I was like, wow finally some sense! And then at the second page of the article it turned out to be 36,990$!!! And then I was like, ho, right.

Jim Austin's picture

The $6990 speakers were Oscar Duo's from a previous review. As JA describes in the early part of the article, we were first planning to review a much cheaper version but ended up with the version with the diamond tweeter, which is much more expensive. Very likely, the cheaper version is almost as good.

Jim Austin, Editor

noamgeller's picture

I read the article again... I got it now... Would have been nice thou at 6995$ oh well :)

Kursun's picture

New loudspeakers come and go, often at exaggerated prices. 35 Years ago I had secured a pair of Yamaha NS-1000M's. For me they are still the best loudspeakers money can buy. Provided of course they are driven by first rate, preferably Class A amplifiers. Funny, their list price was only $1500.

JRT's picture

Technology has advanced. You should listen to some of the newer better loudspeakers.

Kursun's picture

Not as much as you think...

Homer Theater's picture

Changes are RADICAL today compared to the 1970s when the NSM-1000M was designed. Materials improve, understanding of the physics improved, computer modeling/design software has made HUGE, nearly unimaginable changes compared to what was possible in the 1970s. Crossover design is massively better today than 50 years ago. Today's high quality electronic components did not exist in the 1970s. NON-DISCLAIMER: This is written by someone who recommended Yamaha NSM-1000s to three different friends in the 1970s who all loved them after their initial freak-out at the cost of them compared to the guy in the parking lot with a van full of big $25 speakers. I was well aware of how good NSM-1000s were in the 1970s. Why didn't I have NSM-1000s of my own? I was already a high-end idiot with speakers that cost 2.5 or 3 times more than NSM-1000s.

Kursun's picture

Computer software only mimics the principles and formulas published half a century ago.
Do you mean no greatly engineered products, structures or buildings could be built before computers?
As a structural engineer, part time professional software developer and an amateur loudspeaker system designer I tend to disagree. Nothing could be further from the truth.

BTW, Yamaha NS-1000Ms were not designed as an upgrade for white van loudspeakers.
They were produced as reference monitor speakers for highest quality recording studios worldwide and discerning audiophiles, regardless of price. They have highest technology in design and materials.

Kursun's picture

Loudspeaker enclosures are still designed with the formulas given by Thiele & Small (published 1960-1970). Crossovers are still designed by formulas given by Butterworth, Linkwitz-Riley, etc (equally old tech).
Actually, not much is new. (Except greedy manufacturers...)
And new doesn't always equal to better.
If you'll ever listen to Yamaha NS-1000M's, you'll understand what I mean.

SET Man's picture

JA: "I kept being tempted to play music loud, though this meant that the huge bass drum hit 12 minutes before the end of Part Two of Gerontius scared the heck out of my cats, who were dozing on top of the speakers."

Reading that gave me a good chuckle, only cat owners would understand. Reminded me of my old cat, he used to hangout on my speakers also. Luckily he was careful getting up and down so I didn't have to worry about he tipping my speaker over.

Awsmone0's picture

Dear JA

I was wondering if you had any thoughts/experience with the quintets and how they compared to the trios?


John Atkinson's picture
Awsmone0 wrote:
I was wondering if you had any thoughts/experience with the quintets and how they compared to the trios?

I am afraid that I have never heard the Quintet.

John Atkinson
Technical Editor, Stereophile