The cheapest version of this circuit costs a few cents while buyers pay vastly more.
The cable debate has always been binary, with skeptics insisting cables can’t change sound while believers swear they hear the difference. But both sides have been overlooking a third option sitting in the patent record since 1992.
Some premium audio cables genuinely alter the signal passing through them, and the proof isn’t in a listening room. It’s in patent filings. MIT Cables founder Bruce Brisson, for one, described passive filter networks wired directly into audio cables, and the US Patent Office classified the invention not as a cable improvement, but as a fixed equalizer.
The twist is that not every measurement proves the same thing.
What the Patents Actually Describe
The patent trail starts with a title that leaves little room for interpretation.
In 1992, MIT Cables founder Bruce Brisson received US Patent 5,142,252 for an “audio signal transmission line with a low pass filter.” Not a superior conductor, not a shielding breakthrough, and not a noise-reduction technique. The invention described a filter built from discrete inductors, the same basic circuit language used across audio electronics.
A second patent arrived fifteen years later with more technical specificity and less blunt wording. Where the first patent announced itself as a filter in the title, US Patent 7,242,780 called itself an “audio signal cable with passive network.” The wording changed, but the core idea remained: a cable with circuit elements intentionally placed in the signal path.
This later patent specifies RC circuits wired between a cable’s conductors, each tuned to a specific audio frequency.
In the guitar cable embodiment, those values range from 30 Hz through 3.5 kHz. And these are not merely stray electrical properties of wire, either. They are selected frequency points in and around the range musicians and listeners recognize as tone.
Plus, patent classification also supports that reading. Because patent examiners assign classification codes, H04B3/144 matters. It places Brisson’s invention under “amplitude-frequency equalisers” and, more specifically, “fixed equalizers.” In plain terms, the examiner classified the invention as a device with a set, non-adjustable frequency response.
What the measurements can and cannot prove
Independent measurements add a narrower but useful confirmation of the patent claims, as they do show that at least one real MIT cable behaves measurably like a filtering device rather than a neutral conductor. However, they do not prove by themselves that MIT’s cable audibly EQs music.
For one, when Alpha Audio ran an eleven-cable megatest with precision measurement equipment, MIT’s EVO Three showed capacitance that “practically goes on tilt” above 100 kHz. This behavior sits above the audible range, so it should not be treated as proof that this specific measurement captures audible-band coloration.
Still, the patent evidence and the measurement evidence prove different parts of the argument:
- The patents show MIT designed cable-integrated passive networks around audio-related frequencies, including examples from 30 Hz through 3.5 kHz.
- Alpha Audio’s measurement confirms unusual filtering behavior in one real MIT cable, though mainly above the audible band.
Basically, they both support the broader conclusion that MIT’s network cables are designed to shape signal behavior, but they do not provide a full published audible-band EQ curve for every model.
Filters by Any Other Name
Brisson’s interviews pick up where the patents leave off, but he describes it a bit differently than his patents do.
In a 2010 Dagogo interview, he acknowledged that his original Shotgun Speaker cables from the mid-1980s were designed as “distributed low pass filters” with high mutual inductance to lower the frequency cutoff.
The same technology the patents describe as filtering, Brisson also described as filtering when discussing the company’s early products.
Later in the interview, Brisson ranked the factors that determine cable quality:
- Articulation, his proprietary term for MIT’s network technology, and impedance shared the top spot.
- Conductor material and conductor geometry landed fourth and fifth.
So he basically placed the network behavior above the cable’s own conductor.
That “other manner” is the filter network the patents describe. Yet by the time Brisson marketed his current product line, the engineering vocabulary had largely disappeared.
“Low pass filters” became “Articulation Poles,” while engineering terms like “phase angle” and “quality factor” gave way to proprietary language. And where the patents describe RC circuits at specific frequencies, the marketing promises cables delivering “around 50% articulation” across “a very, very broad range of frequencies.”
So while the patent uses standard engineering terms that any electrical engineer would recognize, the marketing uses terms that appear in no patent Brisson has ever filed.
When the interviewer pressed Brisson on how the impedance switching mechanism actually works, the answer came twice in the same conversation.
The Price of a Passive EQ
Some listening reports suggest that at least some listeners hear and prefer what MIT’s filter networks do to the signal.
In Alpha Audio’s blind listening test, one evaluator praised MIT’s “detail, imaging and detailing,” ranking the cable third overall. Frank Dernie noted in a separate test that MIT and Goldmund, both cables with inline filter boxes, “sounded different to the other cables in the test.” The coloration is audible to some listeners and genuinely preferred by them.
The cost of that coloration is where the math breaks down.
MIT’s Articulation Control Console carries a forum-cited price of ~US$135,000 (£106,500). That figure is not manufacturer-confirmed, but the product’s positioning at the top of MIT’s lineup is. What the buyer gets for that price is fixed, non-adjustable tone shaping, with frequencies set by MIT and no option to change them.
For $299, a Schiit Lokius offers six bands of adjustable EQ from 20 Hz through 16 kHz with balanced I/O. For $205, a miniDSP 2×4 HD provides ten parametric EQ filters per channel and room correction.
Neither replicates MIT’s specific filter curve, but both give the listener adjustable tone shaping instead of fixed coloration, and both let you change the settings when your preferences or your room change.
Same Circuit, Different Sticker
Alpha Audio’s eleven-cable megatest revealed something beyond MIT: two of the tested cables, MIT and Transparent, featured inline network boxes, and both produced frequency response behavior the testers described as “remarkably similar.”
That comparison supports the network-box argument directly. MIT calls its approach “Articulation,” while Transparent uses different terminology, but both products place additional circuitry in the cable path and both showed similar measured behavior in Alpha Audio’s test.
A third cable, the Driade Flow, complicates the picture. It showed a similar response curve despite using no visible network box, though MIT exhibited “less high loss than either cable.” That means similar measurements should not be treated as proof of identical internal circuitry. They show comparable response behavior, not necessarily the same design.
The useful conclusion is narrower than the original “same circuit” framing. MIT and Transparent fit the argument that network-box cables behave less like ordinary conductors and more like fixed signal-shaping devices. Driade shows that similar measurement patterns can appear even when the construction looks different.
Some buyers will prefer that coloration, and Alpha Audio’s own blind test showed as much. One evaluator praised MIT’s imaging, while the other heard “mid-prominent” sound with inadequate bass from the same cable.
For network-box cables, the choice isn’t between a cable that changes your sound and one that doesn’t. It’s between fixed coloration you can’t control and a $299 equalizer that lets you dial in your own.