ARENDAL 1723 MONITOR THX

Pre owned. In excellent condition. Free from evident signs of wear. Supplied with original packaging.

The Arendal 1723 Monitor THX loudspeaker is designed to deliver precision performance in a compact format, capable of producing high sound pressure levels both as a front channel and as a surround speaker. The entire design is developed with the goal of ensuring faithful, powerful and controlled sound reproduction while maintaining compact dimensions and performance typical of a high-end system.

The cabinet is constructed from high-density HDF, a material chosen for its superior rigidity and its ability to be machined with extreme precision compared to standard MDF. Panel thickness ranges from 18 to 50 millimeters in the most critical areas, such as the driver mounting points and the cabinet base, contributing to an extremely solid and inert structure. Inside the enclosure, strategically placed bracing increases overall rigidity and reduces unwanted panel vibrations that could color the sound. The internal structures are CNC-machined with carefully shaped profiles designed to improve airflow and reduce internal volume losses while maintaining maximum strength at key assembly points. To eliminate any residual resonance, the inner cabinet surfaces are also treated with a butyl-based differential mass damping layer, helping the enclosure remain exceptionally quiet even during listening at very high levels.

The construction philosophy avoids the use of plastic in components that affect sound quality. Structural elements such as the rear plates are made from high-grade aluminum, as is the anodized logo, ensuring long-term durability and stability.

The internal wiring has been designed with great care. High-strand-count multi-strand cables are braided together, chosen not for aesthetics but to achieve stable impedance and excellent current carrying capability. This solution minimizes insertion losses and avoids the “skin effect” typical of large-diameter conductors, ensuring that each driver receives exactly the signal intended by the amplifier without alteration.

At the heart of the Arendal range is a 28 mm synthetic soft-dome tweeter designed to proprietary specifications and paired with a dedicated waveguide. The dome itself comes from the high-end production line of German manufacturer Dr. Kurt Mueller and is characterized by extremely low mass, pistonic behavior up to very high frequencies, and carefully controlled resonances. The frequency response remains smooth and consistent, while the sonic character stands out for its sweetness and naturalness.

The waveguide paired with the tweeter is the result of extensive modeling, testing and refinement. Its purpose is to further enhance the driver’s performance by controlling frequency dispersion. High frequencies, which naturally tend to beam forward, are spread more broadly, while the lower frequencies within the tweeter’s range, which would otherwise disperse in all directions, are more precisely focused. This results in a far more consistent polar response across the tweeter’s entire operating range and allows better integration with the mid-bass driver, simplifying the crossover design.

The tweeter motor is specifically designed for this loudspeaker and optimized through FEA analysis. It features a large neodymium ring magnet, a high-temperature CCAW voice coil and an underhung design that helps reduce distortion. Copper and aluminum shorting rings further improve linearity and lower inductance, while low-viscosity ferrofluid contributes to cooling the voice coil and improving transient response. A large aluminum heatsink helps maintain low operating temperatures and prevents thermal compression. This combination allows the tweeter to operate with high efficiency and a very low crossover point, around 1500 Hz, while maintaining high output and low distortion.

The waveguide that complements the tweeter features a hybrid aluminum and HDF structure designed in-house to maximize performance. In addition to increasing efficiency, it precisely controls directivity, reduces distortion at the lower end of the tweeter’s range and enables a lower crossover point compared with traditional flat-baffle tweeter mounting. The result is a very natural transition between the tweeter and the mid-woofer.

Behind the tweeter dome is a carefully engineered system of air chambers, venting and damping materials designed to precisely control impedance and eliminate secondary resonances that could create electrical phase shifts and produce a harsher sound character.

The speaker employs 8-inch woofers specifically designed for this application and based on the same engineering principles used in Arendal subwoofers. The cones are made from lightweight long-fiber pulp analyzed with the Klippel system and treated with a proprietary formulation that provides inherent damping and pistonic behavior throughout the entire operating range. The motor design uses CCAW voice coils to combine low weight with high conductivity, while an aluminum shorting ring reduces inductance and distortion, expanding the usable frequency bandwidth.

The woofer suspension is designed through FEA simulations to ensure perfectly symmetrical movement and reduce non-linear distortion. Elements such as the NBR surround, Connex spider and integrated tinsel leads work together to allow large excursion while maintaining a linear response. Ventilation beneath the dust cap and within the basket improves voice coil cooling and prevents thermal compression, increasing power handling capability and maintaining a dynamic response even at high listening levels.

The crossover is one of the most complex elements of the design and results from a long process of modeling, measuring and listening. Its role is to ensure a smooth and coherent transition between the mid-woofer and the tweeter while maintaining continuity in frequency response, phase and dispersion both on-axis and off-axis. The 1723 Monitor THX uses a two-way configuration with a crossover frequency of 1500 Hz and fourth-order slopes of 24 dB per octave, a design choice that protects the tweeter at high sound pressure levels and limits out-of-band interactions between the drivers.

The crossover components are audio-grade and built with very tight tolerances. Where suitable components were not available, custom parts were produced specifically for Arendal Sound. The coils are low-resistance air-core types, the capacitors are metallized polypropylene, and the resistors are high-power low-inductance wire-wound models. The circuit is mounted on 1.6 mm FR4 boards with wide one-ounce copper traces to ensure reliability and minimal signal loss.

The connection terminals are made from pure copper, CNC-machined, then polished and plated with rhodium to improve conductivity, corrosion resistance and long-term durability. They accept several types of terminations including banana plugs, spades, pins and bare wire. The supplied jumpers use the same materials as the binding posts to maintain maximum signal quality when bi-wiring is not used. The terminal plate itself is made of brushed and anodized aluminum, providing a rigid and resonance-free structure that directly houses the crossover and allows for possible future upgrades.

The acoustic design begins with a sealed-box alignment with a low Q factor, ensuring extremely precise control of low frequencies and very fast transient response. In this configuration the speaker exhibits a natural roll-off of 12 dB per octave below the system resonance frequency, delivering controlled bass and very linear behavior in typical listening rooms. The absence of ports also minimizes phase rotation and makes integration with a subwoofer particularly easy.

The front grille is a fully custom component made from perforated metal with high airflow, designed not to affect sound quality. A black fabric covering softens its visual appearance while helping damp any residual vibrations. It attaches using hidden neodymium magnets beneath the cabinet surface, avoiding plastic pins and preserving the clean aesthetic of the speaker. A protective rubber layer prevents cabinet damage during installation and ensures a secure fit even during high-level playback. With or without the grille, the speaker maintains both the elegant design and the high acoustic performance that define the entire 1723 series.

Technical specifications:

• Design: 2-way
• Tweeter: 28 mm
• Woofer: 2 x 8″
• Crossover frequency: 1500 Hz
• Frequency response (-6 dB, anechoic): 35 Hz – 20 kHz; typical in-room bass response: 20 Hz; frequency linearity: 50 Hz – 20 kHz ±2.5 dB; F3: 48 Hz; F6: 35 Hz; F10: 27 Hz
• Sensitivity: 89 dB (2.83 V / 1 m)
• Nominal impedance: 4 ohms
• Enclosure type: sealed / vented
• Cabinet material: HDF (High Density Fiberboard)
• Bass ports: 2 x 2″
• Recommended amplifier: up to 400 W RMS at 4 ohms
• Dimensions (H x W x D): 63.5 x 27.5 x 40 cm
• Weight: 26.7 kg