Used QSC GP Series
Used QSC GP Series subwoofer systems are premium, high-performance loudspeakers available in single and dual configurations, delivering very high acoustic output and deep low-frequency extension for ground-stacked or installed applications. Second-hand units from this range offer a capable and well-engineered option for professional audio setups. Scroll down to browse the used QSC GP Series listings currently available.
No listings currently in stock. This page stays live — check back or register interest.
0 listed right now — list yours to the buyers searching this model.
Get an email when a new QSC GP Series is listed.
QSC GP Series specifications
| Brand | QSC |
| Segment | Audio |
About the QSC GP Series
The QSC GP Series comprises premium rectangular subwoofer systems designed for ground-stacked use, spanning dual 18-inch, single 18-inch and dual 12-inch models. The GP218-sw dual 18-inch unit achieves 140.5 dB SPL peak at 1 m with low-frequency extension down to 27.4 Hz, housed in an 18 mm birch ply enclosure with independent dual chambers and internal bracing. The GP118-sw single 18-inch model features a threaded pole cup, dual NL4 Speakon connectors, M10 suspension fittings and interlocking feet for vertical stacking. The GP212-sw dual 12-inch unit reaches 135.4 dB SPL peak at 1 m with extension to 32 Hz in an extremely low-profile 15-inch-tall cabinet. All models are available in black or white finishes, with cinema versions offered for surround LFE use.
QSC GP Series — buyer FAQs
What is the QSC GP Series and what models does it include?
The QSC GP Series is a range of premium rectangular subwoofer systems designed primarily for ground-stacked use. It spans three models: the GP218-sw dual 18-inch, the GP118-sw single 18-inch, and the GP212-sw dual 12-inch. Each model is available in black or white finishes, and cinema versions exist for surround LFE applications.
How does the acoustic output of the GP218-sw compare to the GP212-sw?
The GP218-sw dual 18-inch unit achieves a peak output of 140.5 dB SPL at 1 metre with low-frequency extension down to 27.4 Hz. The GP212-sw dual 12-inch model reaches 135.4 dB SPL peak at 1 metre with extension to 32 Hz, standing only 15 inches tall. Both deliver what QSC describes as tight musical punch alongside deep bass.
What installation and deployment options does the GP118-sw single 18-inch subwoofer offer?
The GP118-sw includes a threaded pole cup so a full-range loudspeaker can be mounted on top, dual NL4 Speakon connectors, and M10 fittings for suspension in both permanent and portable applications. Interlocking feet and recess features allow rigid vertical stacking with other units, and built-in handles ease transport between venues.
Who makes the QSC GP Series and where does it sit in the brand's product range?
The GP Series is made by QSC, an American manufacturer known for professional audio, video and control products including power amplifiers and loudspeaker systems. Within the QSC catalogue the GP Series represents a premium passive subwoofer line, engineered for high acoustic output in professional ground-stacked or installed configurations rather than lightweight portable use.
What should I check when buying a used QSC GP Series subwoofer?
Check which specific model you are buying (GP118-sw, GP218-sw or GP212-sw), the finish colour (black or white), and whether it is a standard or cinema LFE version, as these affect suitability and resale value. Inspect the birch ply enclosure for damage and confirm the Speakon connectors are intact. Used price varies with condition, configuration and age. Every listing on this page carries a 21-day warranty covering major functional faults; full details are in the buying guide at 10kused.com/used-av-equipment-guide/.
