Dolby CS128LF – Dual 15-Inch Low-Frequency Screen Speaker
Dolby CS128LF – Dual 15-Inch Low-Frequency Screen Speaker is backordered and will ship as soon as it is back in stock.
Dolby CS128LF – Dual 15-Inch Low-Frequency Screen Speaker
What is the Dolby CS128LF?
The Dolby CS128LF is a low-frequency screen channel speaker with two custom 15-inch woofers. It is the LF component of both the Dolby System 126 and System 128, sitting beneath a CS126MH or CS128MH mid/high cabinet. Its shallow cabinet suits auditoriums with tight spacing between the screen and the front wall.
How does the Dolby CS128LF work?
Each 15-inch driver sits in an independent chamber within the cabinet for better performance and reliability, and critical driver spacing and alignment optimize vertical dispersion. Acoustic ports exit on both sides of the cabinet rather than the front, which keeps depth to 13.4 inches; the ports also act as integrated handles during unboxing and installation.
A flip-card on the advanced input plate sets the wiring. In parallel mode both woofers run from one amplifier channel at 4 ohms; in independent mode each driver takes its own channel at 8 ohms to make full use of available amplifier power. The cabinet is rated at 600 W @ 49 Vrms with a 420 W measured power draw, covers 39 Hz to 255 Hz with 32 Hz usable response, and produces 129 dB continuous and 139 dB measured peak SPL at one metre.
The low-frequency feed comes from a Dolby CP950A or CP950, amplified by a Dolby Multichannel Amplifier such as the DMA24302.
What are the key features of the Dolby CS128LF?
- Dual custom 15-inch woofers — two drivers deliver 39 Hz to 255 Hz with 129 dB continuous output.
- Flip-card signal routing — choose parallel single-channel 4-ohm or independent dual-channel 8-ohm operation.
- Independent driver chambers — separate chambers improve performance and reliability.
- Side-mounted ports — ports on each side reduce cabinet depth and double as handles.
- Tool-free input plate — high-current, spring-loaded terminals speed installation.
- Floor anchoring option — the BKT.FLR floor-bracket kit (sold separately) secures the speaker stack.
Where is the Dolby CS128LF typically used?
- Cinema auditorium (small to medium)
- Screening room
- Auditorium
- House of worship
Technical Specifications
| Model | CS128LF |
| Frequency range | 39 Hz - 255 Hz |
| Usable LF response | 32 Hz |
| Coverage window | 160° H, 100° V |
| Rated impedance | 4 Ohms parallel / 8 Ohms x 2 (independent mode) |
| Sensitivity @ 1 W | 101 dB |
| Power handling | 600 W @ 49 Vrms |
| Power draw | 420 W |
| Maximum voltage peak | 138 Vpk |
| Max continuous SPL @ 1 m | 129 dB |
| Measured peak SPL @ 1 m | 139 dB |
| Transducers | 15" woofer x (2) |
| Input | Advanced input plate w/ flip card and high-current spring-loaded terminal block |
| Enclosure | Wood |
| Accessories | BKT.FLR floor bracket kit (sold separately) |
| Dimensions (unit) | 40.59" H x 32.74" W x 13.4" D (103.1 x 83.2 x 34 cm) |
| Weight (unit) | 128 lb (58.06 kg) |
| Weight (shipping) | 131 lb (59.42 kg) |
Frequently Asked Questions
Which Dolby systems use the CS128LF?
The CS128LF is the low-frequency section of both the Dolby System 126 (with the CS126MH) and the System 128 (with the CS128MH).
Is it compatible with Dolby Atmos and the CP950A?
Yes. It is part of Dolby's immersive screen speaker line and runs from processors such as the CP950A through Dolby Multichannel Amplifiers.
Can it run on one amplifier channel?
Yes. Set the flip card to parallel mode for a single 4-ohm load, or to independent mode to drive each woofer at 8 ohms from separate channels.
How is it secured?
The optional BKT.FLR floor-bracket kit (sold separately) mechanically connects the speaker stack to the auditorium mounting surface. Follow the Dolby owner's manual.
What warranty and support come with it?
The CS128LF carries Dolby's manufacturer warranty, confirmed with your quote. Creation Networks designs, installs and supports Dolby screen systems; see the Dolby Professional collection and request a quote.
At Creation Networks, we do everything we can to create an excellent customer experience. This includes fast shipping and easy returns.
- Most in-stock orders placed Monday-Friday ship within 24-48 hours. General restrictions apply; please see our full shipping policy here.
- We offer a 30-day return policy from the delivery date on many products. Product restrictions apply. Restocking fees for the return of open-box items. Please see our full return policy here for more information.
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