PSB CS805 (pack of 4)
Overview
The PSB CS805 is an in-ceiling in-wall speaker with a two-way 8-inch design. It is engineered to blend discreetly while delivering sound faithful to the brand’s signature. Its frequency response extends from 48 Hz to 20 kHz, enabling it to cover large listening areas. The CS805 adopts technologies from higher-tier models in a more accessible format.
Technical architecture and optimized components
At the heart of the CS805 is a 203 mm polypropylene-cone woofer, a material chosen for its specific acoustic properties. Polypropylene offers an optimal balance between rigidity and internal damping, allowing the cone to move pistonically across a wide frequency range while minimizing unwanted coloration. The woofer’s foam surround ensures controlled, linear excursion, helping the speaker reach down to 48 Hz with minimal distortion. The stamped steel basket holds everything precisely while limiting parasitic resonances.
The 25 mm textile dome tweeter is the system’s other fundamental element. The treated textile used for the dome combines lightness and rigidity, enabling treble extension up to 20 kHz without audible distortion. The integration of ferrofluid in the tweeter’s magnetic gap serves two crucial functions: thermal dissipation and mechanical damping. This technology, initially developed by NASA in the 1960s for space fuels, has found a particularly relevant application in audio. Ferrofluid, a viscous liquid containing suspended iron oxide particles, significantly improves the tweeter’s power handling by efficiently dissipating the heat generated by the voice coil. At the same time, its magnetic and viscous properties damp parasitic resonances of the dome, contributing to clarity and natural high-frequency reproduction.
The CS805’s Open Back design deserves special attention. Unlike in-wall speakers with a sealed rear enclosure, the open architecture uses the space between the ceiling and the drop ceiling as an acoustic volume. This approach offers several significant acoustic advantages. First, it eliminates internal standing waves that can color the sound in a compact enclosure. Second, it allows the woofer to operate in a larger air volume, promoting extended bass response and preserved dynamics. The integrated first-order crossover ensures a smooth transition between woofer and tweeter, preserving the phase coherence essential to accurate spatial reproduction.
Simplified installation and integration flexibility
The high-strength Delrin retractable “dogleg” mounting system makes installation accessible even to less experienced users. These pivoting mounting tabs deploy automatically as the screws are tightened, clamping the speaker firmly against the back side of the ceiling. This clever mechanism eliminates the need to access the rear of the speaker after insertion into the cutout, significantly simplifying the installation process. The required 245 mm diameter cutout remains within standard dimensions, making it easy to use conventional tools.
PSB supplies two frameless magnetic grilles with each CS805: a round one measuring 270 mm in diameter and a square one of equivalent dimensions. This dual option lets you match the speaker’s look to different architectural styles without compromising acoustic performance. The grilles use strong magnets for secure attachment while remaining easy to remove for maintenance or customization. The acoustically transparent mesh and frameless design contribute to the speaker’s discreet visual integration into its surroundings.
The 111 mm mounting depth remains reasonable for most residential and commercial installations. This compact dimension allows installation where the available space above the ceiling is limited, while preserving the acoustic volume needed for proper woofer operation. Spring-loaded terminals accept cables up to 12 AWG, providing reliable connectivity for longer cable runs without signal degradation.
Acoustic performance and versatile use
The CS805 demonstrates remarkable versatility in potential applications. Its sensitivity of 87 dB in-room (85 dB anechoic) makes it compatible with a wide range of amplifiers, from modest home theater receivers to dedicated power amps. The recommended power range of 10 to 100 watts reflects this flexibility, allowing both background listening and dynamic playback for home cinema.
The nominal impedance of 6 ohms, with a minimum of 4 ohms, remains within a comfortable range for most modern amplifiers. Combined with the speakers’ efficient design, this enables substantial sound levels without overtaxing the amplification electronics. The CS805’s ability to handle large listening areas, repeatedly mentioned in the technical documentation, is explained by the joint optimization of directivity, sensitivity, and power handling.
In a home theater setup, the CS805 naturally fits as an Atmos or DTS:X effects channel, accurately reproducing ambience and effects positioned in the upper hemisphere of the three-dimensional sound field. Tonal consistency with other PSB models allows creation of a cohesive soundstage, essential to the spatial illusion sought in these object-based audio formats. The controlled dispersion of the two-way system ensures uniform coverage of the listening area without creating undesirable acoustic hot spots.
For multiroom installations, the CS805 offers an elegant solution for distributing music across varied living spaces. Its ability to reproduce substantial bass down to 48 Hz often eliminates the need for an additional subwoofer in ambient music applications. The standard white finish and paintable grilles enable seamless architectural integration, preserving the aesthetic of the spaces while adding quality sound.
Technical specifications
Acoustic performance
- Frequency response
- On-axis at 0° ±3 dB: 48–20,000 Hz
- Sensitivity
- Anechoic chamber: 85 dB
- Listening room: 87 dB
- Wide bandwidth for a rich, balanced sound
Electrical characteristics
- Impedance
- Nominal: 6 Ω
- Minimum: 4 Ω
- Recommended input power: 10–100 W
Driver design
- Tweeter: 1” (25 mm) treated textile with ferrofluid for precise, natural highs
- Woofer: 8” (203 mm) black polypropylene with stamped steel basket and foam surround for deep bass
- Crossover: first-order high-pass filter
- Type: rear-ported
Dimensions and installation
- Ceiling cutout: 245 mm
- Mounting depth: 111 mm
- Round grille diameter: 270 mm
- Net weight: 1.47 kg per speaker
- Easy installation with sturdy mounts
Finish and accessories
- Finish: white
- Round and square magnetic grilles included
- Low-profile, paintable grilles
Highlights
- PSB signature sound consistent with higher-end models
- Excellent price-to-performance ratio
- Ideal for large rooms and multi-room installations
Frequently Asked Questions
What is the main difference between an Open Back speaker like the CS805 and one with a sealed enclosure?
The Open Back architecture uses the space above the ceiling as an acoustic volume, eliminating internal resonances of a cabinet while allowing the woofer to operate in a larger air volume. This design promotes natural bass response and preserved dynamics, but requires sufficient space above the ceiling to function optimally.
Can I use the CS805 in a bathroom or kitchen?
While the CS805 is not specifically designed for humid environments, its ceiling installation protects it from direct water splashes. In a well-ventilated kitchen or bathroom, it will operate without issue. For environments with very high humidity, PSB offers specifically treated models in its Universal Outdoor range.
Is it possible to paint the grilles to match my ceiling perfectly?
The included white magnetic grilles are indeed paintable. PSB recommends using spray paint rather than a roller or brush to achieve a uniform finish without clogging the acoustic mesh. Remove the grilles from the speaker before painting and let them dry completely before reinstallation.
Which amplifier do you recommend to get the best from the CS805?
With a sensitivity of 87 dB and an impedance of 6 ohms, the CS805 works well with most modern home theater amplifiers. An amplifier delivering 50 to 75 watts per channel into 6 ohms is a good compromise for the majority of applications. For high listening levels in large rooms, an amplifier capable of providing 100 watts will allow you to fully exploit the speaker’s dynamic potential.
Is the CS805 suitable for reproducing Atmos channels in a home theater system?
The CS805 is a particularly relevant choice for Atmos or DTS:X height channels. Its wide dispersion and ability to handle high volumes make it an ideal solution for creating the upper hemisphere of the three-dimensional sound field. Tonal consistency with other PSB speakers ensures seamless integration into the overall system.
- Eco-contribution included in the sale price.
