I first reviewed the Marten Coltrane back in 2004. I liked a lot of what it did, but also found it flawed by a cool tonality and overly analytical presentation and reported accordingly. What goes around comes around and that very same pair of Marten Coltranes were destined to reappear in my listening room. The intervening 18 months of solid use changed the speakers out of all recognition. Gone was the lean, pinched sound, the lack of emotional breadth. In it’s place a richer, fuller sound, ripe with colour and texture. In fact, a whole different speaker – and one that was a whole lot better.
Those original Coltranes weren’t new when they reached me, and well aware that a speaker’s performance can alter out of all recognition as it runs in, I’d beaten the review speakers to pulp (metaphorically speaking) before ever settling down to form an opinion on their performance. But here I was, confronted with the unavoidable evidence that as much running as I’d given them, it simply wasn’t enough. The review I’d written was inaccurate, and worse, misleading to potential owners.
All you can do is learn the lesson and move on. Reviewing the Coltranes made me much, much more aware of just how important running in can be, a fact reinforced by a series of speakers since, many of them also using the distinctive Accuton ceramic drivers. Marten learnt the lesson too, and now their drivers are run for several hundred hours before they’re even installed into speakers. Even so I approached the Coltrane 2 with some trepidation and an insistence that they stay for longer than normal. In fact, they too have come, gone and returned again – doing several shows as well as prolonged periods of constant break-in over that time, so I’m as sure as I reasonably can be that I’m actually hearing what they can do; which is just as well, because it’s quite a lot. But before we get to that, perhaps we’d better understand exactly what the Coltrane 2 actually is…
The original Coltrane remains in the range and is a three-way design, pairing a diamond tweeter and 100mm ceramic midrange driver with two 200mm ceramic bass units, all mounted in a 60mm thick constrained layer baffle, constructed from two layers of solid hardwood. The cabinet is a complex, one-piece, boat-shaped molding, constructed from 25mm thick carbon-fibre. Despite a height of 1130mm and a depth of 610mm (around twice its width) it succeeds in appearing smaller than it actually is – largely due to its rounded rear contours. The Coltrane 2 is the latest addition to the Company’s range, and represents a beefed-up take on the Coltrane recipe. Gone are the wimpy 200mm bass units, replaced with much more macho 280mm versions, using the latest ceramic sandwich technology from Accuton. The midrange driver has expanded to 173mm in diameter and the tweeter has increased from 19 to 25mm. The cabinet has expanded to match, being around 80mm taller and broader, although still much the same depth. The result is a squatter, more planted look that I think suits the speakers’ shape much better. The drivers make a better job of filling the baffle and the whole looks a lot more balanced in terms of its proportions.
At 60kg and hard to get a hold of, the C2s are far easy to handle if you can enlist some aid, although you can manage alone if needs must. Terminals are bi-wirable WBT NextGens and a three position rotary switch beneath them allows for a degree of low-frequency bass compensation. Internal wiring is from Jorma and the speaker is supported on stainless steel outriggers and adjustable Black Diamond Racing cones and pucks – although finding any sort of horizontal surface to act as a reference for rake angle is something of a challenge. I resorted to a straightedge resting on the outriggers, which works well enough for comparative purposes, if not absolute level. Like the original version, the C2 is reflex loaded by a massive, downward facing port – and it matters what surface that port sees. Sat on my (very) solid wooden floor, the Martens sounded happier with a softer interface immediately below the port, and a folded hand towel added an obvious sense of weight and impact to the bottom end, a more palpable and clearly defined soundstage and greater presence through the mid-bass. These are not small differences, so if auditioning the C2s (or other, similarly ported speakers) it is definitely something to consider.
So much for the physical differences: for me, the real story of the C2 is contained in the numbers. Bigger cabinet, bigger drivers – that’s got to add up to greater sensitivity or deeper bass, right? Well, not apparently in this case. The bottom-end extension and sensitivity of the C2 is quoted as identical to the Coltrane*, the only difference being a slightly milder impedance characteristic, now quoted as eight Ohm nominal as opposed to six. What’s more, the crossover points have dropped considerably. The logic behind three-way designs is that a single driver covers the critical vocal range. This generally dictates crossover frequencies of around 300 and 4500Hz, avoiding the awkward 3kHz junction that occurs in most two-way designs. The Coltrane follows that pattern, with second order slopes centered on 350 and 4000Hz. But if you think that 4kHz is flirting with the vocal range, how about 2.8kHz – ‘cos that’s where the C2 crosses over from midrange to tweeter.