AKG K-240M

AKG's "totally sound-and comfort-engineered" headphone - the version of the K-240 that asked for 600 ohms and got a studio's worth of respect.

Overview

The K-240M is the monitor branch of AKG's long-running K-240 family. The catalog copy is blunt about what the company thought it had built: "the first totally sound-and comfort-engineered headphone incorporating all the features necessary for complete listening enjoyment." That's marketing, and it should be read as such. But the two promises buried in that sentence, accurate stereo imaging and comfort over long sessions, are what working engineers care about, and the K-240M's reputation rests on them.

The spec sheet that survives in distributor literature is where the K-240M gets interesting, and also confusing. One listing gives the frequency response as 15 Hz to 20,000 Hz with a 4-600 ohm impedance and a manufacturer's list price of $120.00. A second listing quotes the same 15 Hz-20,000 Hz figure and the same 4-600 ohm range, but at a list of $99.00, sold through BSW at $82.75. A third entry in the same distributor's pages lists an unnamed model at 20-20,000 Hz and 70 ohms for $79.00. Those numbers don't match either K-240M listing and may belong to a different headphone entirely. Treat the 15 Hz-20,000 Hz / 4-600 ohm / $120 combination as the most complete description of the K-240M. The $99 and $79 figures point to pricing and spec presentation shifting across catalog printings, not to a different design.

That "4-600 ohm" rating is the detail worth pausing on. It reads like a misprint, but it reflects a real trait of the K-240 lineage: the family was built around high-impedance loads meant for console and headphone-amplifier outputs with real voltage swing. Those figures belong to the M, and they sketch its limits: clean through the mids, with bass headroom that thins out at high levels. Anyone buying a K-240M today to drive from a phone should know a proper amplifier is not optional.

AKG's own advertising in the trade press is the best evidence of how the company positioned the M. Mix (February 2003, p.43) ran copy describing the K240M and K141M as "industry standards" while announcing the newer K240 Studio and K141 Studio. The same advertisement touted the new XXL transducer and 55-ohm impedance of the Studio version as offering "louder and better sound than ever before," which is a polite way of saying the old high-impedance design was harder to drive. The K-240M was built for a specific signal chain.

Comfort is one claim that has held up across the family. The catalog language promises "extreme comfort with virtually no fatigue under prolonged use," and the K-240 platform's survival across decades of studio work, with revisions rather than replacements, is the strongest argument in its favor. The K-240M shares that chassis. The archive does not have production years, a confirmed original retail date, or independent lab measurements specific to the M.

What remains is a headphone that occupies an odd, honorable place in AKG's catalog: a monitor-grade variant of a design that became studio furniture, priced between roughly $82 and $120 depending on the dealer and the year, specified to a 15 Hz–20,000 Hz window, and built to be worn for a full session without complaint. It is not the version to buy if you want to plug into a laptop. It is the version to buy if you have a real headphone amp and want to hear what the K-240 family sounded like before the impedance wars were settled in favor of convenience.

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