Klipsch THX-504-L THX Select 2 In-Wall LCR Speaker (Each) at Vinyl Sound Toronto Canada

The THX-504-L is a THX Select 2 Certified 2-way in-wall LCR speaker from Klipsch (Indianapolis, Indiana, USA), available at Vinyl Sound in Toronto, Canada. Part of Klipsch's THX Cinema Series, it is engineered to deliver effortless dynamic range and cinema-grade sound reproduction in a completely flush-mount architectural installation. The speaker combines four 5.25" High-Output Fiberglass Cone Woofers with a 1" Titanium Diaphragm Compression Driver mated to a 90° x 90° square Tractrix Horn, operating as a 2-way design with a three-point crossover at 250Hz and 2100Hz. It delivers a measured frequency response of 46Hz to 20kHz (+/-3dB) at 92dB sensitivity and 8 ohms, handling 150W continuous and 600W peak. The THX Select 2 certification validates consistent, compelling audio performance for rooms of 2,000 cubic feet or larger, and the infinite baffle enclosure design uses the wall cavity as a working acoustic environment. The THX-504-L mounts horizontally or vertically and is timbre-matched to all other Klipsch THX Cinema Series products for seamless full-system integration.

Four 5.25" Woofer Array and 90° x 90° Square Tractrix Horn

The THX-504-L's most distinctive design feature is its array of four high-output 5.25" fiberglass cone woofers, which are arranged in a vertical column flanking the central 1" titanium diaphragm compression driver. This multiple-woofer line-source arrangement provides substantially greater combined cone area than a single large-diameter driver, spreading the low-frequency load across four individual drivers to reduce excursion demands, lower distortion at high output levels, and extend the usable power handling to 150W continuous and 600W peak. The 5.25" fiberglass woofers are mounted to an aluminum motorboard and ABS frame structure, which provides a rigid, resonance-resistant baffle for the driver array. The central 1" titanium diaphragm compression driver couples into a 90° x 90° square Tractrix horn, generating controlled symmetrical high-frequency dispersion that maintains consistent tonal balance across the full horizontal and vertical listening area. The dual crossover points at 250Hz and 2100Hz manage the handoff between the woofer array and the compression driver across a three-way-style frequency partition, contributing to the 46Hz to 20kHz operating range that begins deeper than many single-driver in-wall LCR designs.

THX Select 2 Certification and Infinite Baffle Installation

THX Select 2 is the mid-tier THX certification for home theater speakers, validated for rooms of 2,000 cubic feet or larger. Where THX Ultra2 addresses the largest dedicated cinema rooms, THX Select 2 covers the broad range of standard living rooms, open-plan spaces, and mid-size dedicated home theaters where reference-level performance is desired without the room volume requirements of the Ultra2 tier. The THX-504-L uses an infinite baffle enclosure type, meaning the wall cavity behind the speaker acts as the acoustic working volume rather than a sealed or ported back-can. This allows the speaker to achieve its 46Hz low-frequency extension by leveraging the larger effective air volume of the wall and room cavity, which a sealed back-can of equivalent size could not replicate. The THX-504-L mounts at 3.75" depth and is rated for both horizontal and vertical installation with consistent performance in either orientation, making it suitable for center channel positions below a projection screen as well as upright left and right channel positions.

Key Features

• THX Select 2 Certified: Validated by THX Ltd. for consistent, effortless dynamic range and cinema-quality sound in home theater rooms of 2,000 cubic feet or larger, meeting THX directivity and output standards for the mid-to-large residential room tier.
• Four 5.25" High-Output Fiberglass Cone Woofers: A vertical array of four drivers provides substantially greater combined cone area than a single woofer, distributing the acoustic load to lower distortion at high power levels and extending bass response to a measured 46Hz.
• 1" Titanium Diaphragm Compression Driver with 90° x 90° Square Tractrix Horn: A titanium diaphragm compression driver in Klipsch's proprietary square Tractrix horn geometry delivers controlled symmetrical high-frequency dispersion at high efficiency and low distortion across the full listening area.
• Dual Crossover Points at 250Hz and 2100Hz: The three-point crossover network manages the frequency handoff between the woofer array and the compression driver, contributing to the deep 46Hz lower extension and smooth integration through the critical midrange band.
• Infinite Baffle Enclosure Design: The wall cavity behind the speaker serves as the working acoustic volume, allowing the THX-504-L to reach deeper bass extension than a sealed back-can of equivalent footprint, and integrating the speaker fully into the wall construction.
• Horizontal and Vertical Installation: The THX-504-L delivers consistent performance in both mounting orientations, providing flexibility for center channel horizontal mounting below or above a projection screen and vertical LCR mounting in left and right front positions.
• Timbre Matched to Klipsch THX Cinema Series: Spectrally matched to the THX-8000-S surround speaker and all other Klipsch THX-certified products, enabling tonal coherence across all channels in a complete system build.
• Sure-Grip Mounting Dogs: Cam-style mounting dogs distribute clamping force evenly around the drywall cutout for long-term installation reliability without shifting or loosening over time.
• Edge-to-Edge Magnetic Paintable Grille: A full-face grille secured by premium Neodymium magnets covers the entire speaker face, accepts standard interior wall paint, and removes without tools for driver inspection.

Technical Specifications

Frequently Asked Questions

What is the Klipsch THX-504-L?

The Klipsch THX-504-L is a THX Select 2 Certified 2-way in-wall LCR speaker featuring four 5.25" fiberglass cone woofers and a 1" titanium diaphragm compression driver with 90° x 90° square Tractrix horn, delivering a frequency response of 46Hz to 20kHz at 92dB sensitivity and 8 ohms nominal impedance. It handles 150W continuous and 600W peak, uses an infinite baffle enclosure design at 3.75" mounting depth, and is designed for left, center, and right channel use in home theater rooms of 2,000 cubic feet or larger.

How does the Klipsch THX-504-L compare to the THX-8000-L and the JBL Synthesis SCL-2?

The Klipsch THX-504-L and THX-8000-L are both part of the Klipsch THX Cinema Series and are timbre-matched for system use, but differ in certification tier and acoustic architecture. The THX-504-L carries THX Select 2 certification for rooms of 2,000 cubic feet or larger and uses an infinite baffle design with four 5.25" fiberglass woofers for deeper bass extension to 46Hz. The THX-8000-L carries the higher THX Ultra2 certification for rooms of 3,000 cubic feet or larger and uses a sealed back-can with a single 8" woofer, which provides more predictable performance independent of wall cavity conditions. Compared to the JBL Synthesis SCL-2, the THX-504-L uses a higher driver count and an open-baffle design philosophy to achieve greater cone area and deeper extension, while the SCL-2 uses sealed back-can loading for more consistent installation results across varying wall constructions.

What is THX Select 2 certification and what room size does it require?

THX Select 2 is the mid-tier THX home theater speaker certification, validated by THX Ltd. for multi-channel audio reproduction at reference levels in home theater rooms from roughly 2,000 cubic feet upward. It specifies requirements for output capability, controlled directivity, and flat frequency response under standardized test conditions. THX Select 2 occupies the tier between THX Select (entry-level) and THX Ultra2 (the highest residential tier, validated for 3,000 cubic feet or larger). A THX Select 2 certified speaker is the appropriate choice for standard dedicated home cinemas, large living rooms, and open-plan spaces in the mid-to-large volume range where THX Ultra2 would be over-specified.

What does infinite baffle mean for the THX-504-L and does it affect installation?

Infinite baffle means the THX-504-L uses the wall cavity behind the speaker as its working acoustic environment rather than a self-contained sealed or ported back-can. The wall cavity provides a large air volume that allows the four 5.25" woofers to extend bass response to 46Hz, lower than a comparably sized sealed back-can would permit. The practical implication is that the acoustic performance of the THX-504-L is influenced to some degree by the wall cavity volume and construction. Builders and custom installers who want the most consistent and predictable results should frame a dedicated back-box enclosure of appropriate volume behind each speaker during construction, which isolates the acoustic environment from the variability of the wall cavity and also prevents low-frequency energy from crossing into adjacent rooms through shared stud bays.

Can the Klipsch THX-504-L be installed horizontally for center channel use?

Yes, the Klipsch THX-504-L is rated for both horizontal and vertical installation and delivers consistent performance in either orientation. Horizontal mounting is the standard approach for center channel positions below or above a projection screen or flat-panel display, where the 27.25" long dimension runs side to side. The 90° x 90° symmetrical dispersion of the square Tractrix horn maintains even coverage whether the speaker is mounted vertically for LCR use or rotated 90° horizontally for center channel use, which is an intentional design requirement of the THX Select 2 certification for LCR speakers.

What amplifier or AV receiver is compatible with the Klipsch THX-504-L?

The Klipsch THX-504-L operates at 8 ohms nominal impedance with 92dB sensitivity and a recommended amplifier power of 150W per channel. Any AV receiver or separate power amplifier capable of stable 8-ohm operation with 75W to 150W per channel continuous is suitable for most installations. For larger rooms or demanding reference-level playback, a dedicated multichannel amplifier such as the Anthem MCA series, Parasound Halo A 51, or Emotiva XPA series will extract the best dynamic capability from the speaker's 600W peak power handling capacity. THX Select 2 certified AV receivers from Denon, Marantz, Yamaha, and Onkyo are validated for matching performance with THX Select 2 certified speakers.

Where can I buy the Klipsch THX-504-L in Toronto or Canada?

The Klipsch THX-504-L In-Wall LCR Speaker is available at Vinyl Sound, an authorized Klipsch dealer in Toronto, Canada. Vinyl Sound carries the complete Klipsch THX Cinema Series lineup and can assist with system configuration, channel matching, back-box enclosure planning, and amplifier selection for custom home theater builds in the Toronto area and across Canada.

Is the Klipsch THX-504-L timbre matched to the THX-8000-S surround speaker?

Yes, the Klipsch THX-504-L is spectrally matched to the THX-8000-S surround speaker and all other Klipsch THX Cinema Series products. This timbre matching ensures consistent tonal character across all channels in a complete system build, so sounds panning between the front LCR array and the side or rear surround positions maintain the same textural quality without audible tonal discontinuity. A common configuration pairs three THX-504-L units for the front LCR with THX-8000-S speakers for side and rear surround channels, creating a full THX-certified in-wall home cinema system with consistent Klipsch acoustic character throughout.