The SAP-18SFF Empty is a professional 18" subwoofer cabinet designed for musicians, DJs, and sound engineers who want to build their own custom bass system. This vented enclosure lets you choose your preferred 18" woofer to match your specific power and tonal requirements.

Built for serious low-end reinforcement, this passive subwoofer cabinet delivers the deep bass foundation your PA system needs. The vented design optimizes airflow and bass response, while the robust construction handles the physical demands of heavy bass reproduction without cabinet flex or rattling.

The cabinet features 5/8" plywood construction with black carpet covering and protective metal corners for road-worthy durability. Dual 1/4" and dual Speakon input connectors accommodate various amplifier configurations, while the included jack plate and speaker wire simplify your installation. At 55 pounds and measuring 28" × 22" × 22", it strikes a practical balance between performance and portability.

Perfect for band PA systems, DJ setups, churches needing contemporary worship bass reinforcement, and mobile performers playing venues up to 500 people. The integrated pole mount on top accommodates main speakers for a complete full-range system setup.

Connect your powered amplifier to the Speakon or 1/4" inputs using standard speaker cables. The cabinet includes mounting hardware and speaker wire to complete your driver installation.

Backed by Seismic Audio's one-year warranty with fast shipping nationwide. Professional-grade construction at a price point that makes custom subwoofer builds accessible to working musicians and sound professionals.

Technical Specifications

Frequently Asked Questions

What size driver does this cabinet work with?

This cabinet is designed specifically for 18" woofers. You'll need to purchase a separate 18" subwoofer driver that matches your power requirements and tonal preferences. The cabinet includes mounting hardware and pre-wired connections to make driver installation straightforward.

How many people can this subwoofer handle when properly loaded?

When loaded with an appropriate 18" driver and powered adequately, this cabinet can provide bass reinforcement for venues holding 300-500 people. The actual coverage depends on your driver choice, amplifier power, and venue acoustics, but the cabinet construction can handle high-power applications.

What cables do I need to connect this subwoofer?

You'll need standard speaker cables with either 1/4" or Speakon connectors to run from your powered amplifier to the cabinet's input panel. The cabinet includes dual inputs of each type, so you can daisy-chain multiple subwoofers or use the connection method that matches your amplifier outputs.

Can I stack this cabinet or mount speakers on top?

Yes, the cabinet features a pole mount on top that accommodates standard speaker poles for mounting main PA speakers. The sturdy construction also allows for stacking multiple subwoofer cabinets, though you should ensure proper weight distribution and stability for safety.

How does this compare to buying a loaded subwoofer?

Empty cabinets give you complete control over your driver choice, letting you match the woofer's power handling and sound characteristics to your specific needs and budget. You can upgrade or replace just the driver later without replacing the entire cabinet, making this a more flexible long-term investment than pre-loaded options.

WARNING: This product can expose you to chemicals including Di(2-ethylhexyl)phthalate (DEHP), which is known to the State of California to cause cancer. For more information, go to: www.P65Warnings.ca.gov