PSB CSIW SUB28 In-Wall Subwoofer

PSB CSIW SUB28 Dual 8-Inch In-Wall Subwoofer at Vinyl Sound Buffalo NY

The PSB CSIW SUB28 is a dual 8-inch in-wall subwoofer with two carbon fibre cone woofers with rubber surround and steel basket, housed in a sealed metal cabinet measuring 13½ inches wide by 25⅜ inches tall by 3¾ inches deep. Available at Vinyl Sound in Buffalo, New York, the CSIW SUB28 is a passive in-wall subwoofer designed to pair with the PSB CS 500W architectural subwoofer amplifier, which delivers 500 watts RMS into the CSIW SUB28's 4-ohm nominal impedance. The sealed cabinet design provides a controlled, well-damped bass response with minimal port noise or low-frequency overhang compared to a ported enclosure, at the cost of higher amplifier power requirement for equivalent output — a trade-off well-suited to the CS 500W's 500-watt output rating. The cabinet interior volume is 0.3 ft³. The metal cabinet and metal grille face are both more rigid than the wood or MDF enclosures typical of in-wall speaker systems, reducing panel resonances that could color bass output in the low-frequency range. The white paintable grille can be finished to match the wall surface color after installation, making the CSIW SUB28 visually invisible in the room. Heavy-duty nylon dog ears secure the enclosure to wall drywall from the front after insertion through the cutout, and the unit is compatible with new construction and retrofit applications. At 26 lb (12 kg), two-person installation is advisable for the wall cutout positioning. The CSIW SUB28 is part of Vinyl Sound Buffalo's full speaker collection, which includes in-wall subwoofer systems, in-ceiling speakers, on-wall speakers, and amplification from leading audio brands.

Dual 8-Inch Carbon Fibre Woofers, Sealed Metal Cabinet, and 4-Ohm Impedance

The CSIW SUB28 uses two 8-inch woofers with carbon fibre cones, rubber surrounds, and steel baskets operating in a sealed metal enclosure. Carbon fibre cones provide a high stiffness-to-mass ratio suited to the large excursion demands of subwoofer operation — at low frequencies, a subwoofer woofer cone moves significantly more back-and-forth than a midrange or tweeter driver, and a stiffer cone maintains its shape under that mechanical stress rather than flexing unevenly and introducing harmonic distortion. Rubber surrounds provide the compliant, durable suspension needed to support large excursion at low frequencies over the subwoofer's service life. Steel baskets are appropriate for subwoofer applications where the primary structural requirement is rigidity — steel baskets are heavier than cast aluminum but provide adequate dimensional accuracy for the voice coil-to-gap alignment that low-distortion subwoofer performance requires. The two 8-inch drivers share the sealed 0.3 ft³ metal enclosure, with both drivers radiating into the room through the single wall opening. The nominal 4-ohm impedance places the CSIW SUB28 directly at the CS 500W amplifier's rated load impedance, allowing the amplifier to deliver its full 500-watt RMS output to the enclosure without impedance-related power derating.

Sealed vs Ported Design, Wall Installation, and CS 500W Pairing

The CSIW SUB28's sealed cabinet design differs from a ported (bass reflex) subwoofer enclosure in its acoustic behavior below the resonance frequency. A sealed enclosure rolls off smoothly below its resonance at a relatively gentle slope, providing predictable behavior and minimal group delay (time-domain smearing) through the bass range. A ported enclosure uses a tuned port to extend output below resonance but rolls off more steeply below the port's tuning frequency, and the port introduces group delay around the tuning frequency. In a home theater context where timing accuracy of low-frequency effects matters for impact and transient punch, the sealed design's lower group delay is an audible advantage. The PSB CS 500W amplifier's DSP includes a predefined EQ profile for the CSIW SUB28, which applies equalization to flatten and extend the sealed enclosure's bass response below its natural rolloff — the amplifier's 500-watt output provides the headroom needed to compensate for the sealed enclosure's lower bass sensitivity relative to a ported design. Installation requires cutting a wall opening approximately 13½ inches wide by 25⅜ inches tall. The nylon dog ears clamp the metal enclosure to the drywall from the front. The metal grille face installs magnetically over the cutout after the enclosure is secured.

Specifications

Frequently Asked Questions

What is a sealed in-wall subwoofer and how does it differ from a ported design?

A sealed subwoofer enclosure is a completely airtight cabinet — the woofer drives air into a closed volume with no ports or openings other than the speaker opening itself. The sealed air volume creates a restoring force on the woofer cone that adds to the driver's own suspension compliance, resulting in a subwoofer that rolls off bass response below its tuning frequency at a gentle 12dB per octave slope. This gentle rolloff means sealed subwoofers maintain some output well below their rated bass extension, produce lower group delay (time-domain distortion) across the bass range, and recover quickly from transients without the overhang that occurs when a ported enclosure's port resonance sustains bass output after the drive signal has stopped. A ported enclosure extends bass output lower but at the cost of a steeper 24dB-per-octave rolloff below the port tuning frequency and higher group delay near the port resonance. For home theater applications where the timing accuracy and impact of low-frequency effects matter — explosions, bass guitar, kick drum — the CSIW SUB28's sealed design produces a tighter, faster bass character than a comparable ported design would in the same wall cutout size.

How does the CSIW SUB28 pair with the PSB CS 500W amplifier?

The CSIW SUB28 has a nominal impedance of 4 ohms — exactly the load impedance at which the CS 500W delivers its full 500-watt RMS output rating. One CS 500W amplifier drives one CSIW SUB28 at the amplifier's full rated power. The CS 500W's DSP includes a predefined EQ profile calibrated specifically for the CSIW SUB28 enclosure, which applies frequency response correction optimized for the sealed 0.3 ft³ enclosure volume and the two 8-inch drivers' Thiele-Small parameters. Selecting the CSIW SUB28 profile in the CS 500W's DSP menu replaces the need for manual EQ tuning or an external room correction system to get the subwoofer performing to PSB's design specification. The CS 500W's built-in limiter also prevents the amplifier from driving the CSIW SUB28 beyond its mechanical excursion limits, protecting the woofers during high-output home theater passages.

Can the CSIW SUB28 be installed in both new construction and retrofit applications?

Yes. The CSIW SUB28 supports both new construction and retrofit wall installation. In new construction, the wall opening can be framed out before drywall is applied, and the CSIW SUB28 can be positioned precisely during the framing stage. In a retrofit installation into an existing finished wall, a rectangular cutout is made in the drywall and the CSIW SUB28 is inserted from the front. The heavy-duty nylon dog ear clamps secure the metal cabinet to the drywall face after insertion. Because the CSIW SUB28 is a sealed enclosure that uses the wall cavity as no part of its acoustic design — unlike some in-wall speakers that use the wall stud bay as an acoustic volume — the installation site does not require a specific stud bay depth or cavity preparation. The wall opening must be in a location that allows the 3¾-inch depth of the metal enclosure to fit within the available wall cavity depth between the drywall faces, with clearance for the dog ear mechanism.

What does "white paintable grille" mean for the CSIW SUB28?

The CSIW SUB28's grille is a metal perforated panel factory-finished in white primer — a surface specifically prepared to accept latex or oil-based paint. After installation is complete and the grille is in place on the wall, the installer or homeowner can paint the grille face with the same wall color used on the surrounding drywall surface. When the grille color matches the wall, the CSIW SUB28 is visually continuous with the wall plane — the subwoofer is present in the room but not identifiable as a speaker. This is the defining aesthetic advantage of a paintable-grille in-wall subwoofer over a freestanding subwoofer cabinet or a subwoofer with a fixed black or white grille: the CSIW SUB28 adds no visual presence to the room once the grille is painted. The metal grille face is acoustically transparent — the perforation pattern allows bass frequencies to pass through the grille without significant attenuation.

What is the internal cabinet volume and why does 0.3 ft³ matter for a subwoofer?

The CSIW SUB28's sealed enclosure has an internal volume of 0.3 cubic feet (approximately 8.5 liters). Cabinet volume is a primary parameter in subwoofer design: for a sealed enclosure, the internal volume determines the resonance frequency and Q factor of the combined driver-enclosure system — a smaller volume raises the resonance frequency and increases the Q (making bass output more peaked and the rolloff slope faster), while a larger volume lowers the resonance frequency and produces a flatter rolloff. PSB engineers the CSIW SUB28's 0.3 ft³ volume to work with the specific driver parameters of its two 8-inch woofers, and the CS 500W amplifier's predefined CSIW SUB28 EQ profile applies bass boost below the enclosure's natural rolloff to extend effective bass output to a flat response down to the target low-frequency limit. The sealed metal cabinet maintains this volume precisely without the flexing or expansion that an MDF or thin-walled cabinet can exhibit at high output levels, contributing to the CSIW SUB28's low distortion character at high listening levels.

Does the CSIW SUB28 require the PSB CS 500W or can it use a standard AV receiver?

The CSIW SUB28 is a passive subwoofer enclosure — it has no built-in amplifier and requires an external amplifier connected to its speaker terminals. A standard AV receiver's powered subwoofer output is a line-level RCA output (LFE or subwoofer pre-out), not a speaker-level amplifier output, so a receiver's subwoofer output cannot drive the CSIW SUB28 directly. The CS 500W is the recommended amplifier because it provides 500 watts RMS at the CSIW SUB28's 4-ohm load, includes the predefined PSB DSP EQ profile for the CSIW SUB28 enclosure, and accepts the low-level RCA input from an AV receiver's subwoofer pre-out. An alternative passive subwoofer amplifier — any amplifier that accepts a line-level subwoofer input and provides a speaker-level output rated for 4-ohm loads — could technically drive the CSIW SUB28, but would not have the PSB-calibrated EQ profile for the enclosure and would require manual equalization to optimize bass performance.

Where to buy the PSB CSIW SUB28 in-wall subwoofer in Buffalo NY?

The PSB CSIW SUB28 is available from Vinyl Sound, an authorized PSB dealer in Buffalo, New York. Vinyl Sound also carries the PSB CS 500W subwoofer amplifier, which is the recommended amplifier pairing for the CSIW SUB28. Free shipping is available across the continental United States. Contact Vinyl Sound Buffalo by phone or email to purchase the CSIW SUB28, order it as part of a CS 500W and CSIW SUB28 system bundle, or discuss in-wall subwoofer options for your home theater installation.