Dexter Quartet
Nothing between the listener and the music.
Technology earned, not borrowed.
Dexter Quartet is a 3-way floorstander sharing its architecture with the flagship — the same diamond tweeter, the same ceramic midrange, the same approach to cabinet and bass loading. For rooms where Quintet’s proportions exceed what the space calls for, Quartet delivers the essential character of the series without compromise in the frequency ranges that define it.
Three drivers, resolved as one design.
Three drivers, each designed by Marten, each working in its own range. Around them, every element — cabinet, crossover, bass loading — has been developed to the same standard. A triple-layer cabinet built to remove resonance from the equation. A crossover resolved individually for the drivers it serves. A bass loading system that delivers deep, controlled output with minimal distortion. The integration is the design.
The tweeter is diamond. Not as an option. Not as an upgrade. It was the starting point for every design decision that followed.
The engineering is present in every detail.
You simply cannot hear it.
Features
Diamond tweeter
The hardest diaphragm material available, with a stiffness-to-mass ratio no other material matches. Pistonic motion beyond the audible range — vanishingly low distortion, transient response that reflects what is recorded rather than approximating it.
Ceramic midrange
A 3.5″ ceramic midrange, designed by Marten, sits at the heart of Dexter Quartet. High stiffness and low mass keep it pistonic across its full operating range — the transparency and control it delivers define the tonal character of the design.
Carbon fibre bass
A 9.5″ carbon fibre cone driver handles the low frequencies in Dexter Quartet. High stiffness and low mass — the combination that keeps the cone pistonic at the frequencies that define bass dynamics and control.
Multi-diverse crossover
A custom crossover developed specifically for Dexter. Each order and transition point is resolved individually — not as a compromise between constraints, but as a deliberate choice for the drivers it serves.
Bass loading
The Loaded Reflex Line manages bass through a shaped internal channel that exits through a wide downward-firing slot — a principle shared with Coltrane Quintet. Reduced air velocity. Deeper, more controlled output. Greater freedom in placement.
Jorma Duality wiring
Jorma Duality, handmade in Sweden. Ultra-pure copper conductors forming a direct signal path from crossover to driver. Standard across every model in the series.
The speaker disappears.
The music does not.
Marten Isolators, developed with IsoAcoustics, substantially decouple the cabinet from the floor — reducing resonance transfer and opening the soundstage. The cabinet is M-Core triple-layer construction, with a carbon fibre laminate faceplate surrounding the tweeter.
Four finishes,
hand-applied.
Four finishes, each expressing the same design in a different material. True Grain Oak — new to Marten and exclusive to the Dexter series — retains the natural texture of the wood, tactile in a way that is particular to this finish. The matte veneers are hand-sanded and sealed. The piano finishes are built up through multiple lacquer layers and polished to depth.
Dexter Quartet
| Configuration | 3-way |
| Tweeter | 1" Marten pure diamond |
| Midrange | 3.5" Marten ceramic |
| Bass | 9.5″ Marten carbon fibre |
| Crossover | Multi-diverse order, 500 and 4,000 Hz |
| Frequency response | 21–45,000 Hz ±2dB |
| Sensitivity | 89dB / 2.83V |
| Impedance | 6 ohms (3.8 ohms min) |
| Power rating | 300W |
| Terminals | Single-wiring, pure copper rhodium-plated |
| Internal wiring | Jorma Duality |
| Cabinet | M-Core triple-layer |
| Dimensions W × H × D | 28–34.3 × 105 × 36 cm 11.0–13.5 × 41.3 × 14.2″ |
| Weight | 60 kg |
| Stands | Mirror polished stainless steel with Marten Isolators |
| Finishes | True Grain Oak · Matte Walnut · Piano Walnut · Piano Black |
| Internal wiring | Jorma Statement |
| Crossover | Highest quality components |
Handbuilt in Mölndal, Sweden.