The Magma-118S delivers deep, controlled bass for live sound reinforcement where you need serious low-end extension. This passive 18" subwoofer handles 800 watts RMS (1600 watts peak) and reaches down to 40 Hz, making it the foundation piece for professional PA systems in venues that demand full-range sound.

Built around a heavy-duty 18" driver with a 90-ounce magnet and 4" voice coil, the Magma-118S reproduces the low frequencies that smaller speakers can't handle. The ported cabinet design maximizes output while maintaining tight bass response, delivering up to 125 dB peak SPL from its 8-ohm configuration.

The frequency response spans 40-180 Hz, perfectly positioned to handle kick drums, bass guitar fundamentals, and synthesizer low end without muddying the midrange. At 107 pounds and built from reinforced MDF with a powder-coated metal grille, this cabinet balances portability with the structural integrity needed for high-output bass reproduction.

Use the Magma-118S to add bass reinforcement to your main speakers for venues up to 500 people, whether that's contemporary church worship services, DJ events, live bands, or outdoor festivals. The integrated pole mount accommodates a top speaker for a complete ground-stack system.

Connect via dual Speakon input/output connectors using standard speaker cables from your amplifier or powered mixer. The pass-through design allows daisy-chaining multiple units.

Seismic Audio backs the Magma-118S with a one-year warranty and fast shipping, delivering professional bass extension at a price that works for working musicians and venues.

Technical Specifications

Frequently Asked Questions

What amplifier power do I need to drive the Magma-118S?

You'll want an amplifier that can deliver 800-1000 watts RMS into 8 ohms to fully power this subwoofer. Most professional power amplifiers or powered mixers with dedicated subwoofer outputs will work well. Make sure your amp has Speakon outputs or use Speakon-to-1/4" adapter cables.

How many people can this subwoofer handle for a live event?

The Magma-118S provides sufficient bass reinforcement for venues up to 500 people when paired with appropriate main speakers. For smaller indoor events (100-200 people), one unit is typically adequate. Larger outdoor events or dance music applications may benefit from two units for even bass coverage.

Can I use this subwoofer without main speakers on top?

While the pole mount is designed to support a top speaker for full-range coverage, you can use the Magma-118S as a standalone bass reinforcement unit. However, you'll need separate main speakers to handle midrange and high frequencies since this subwoofer only reproduces 40-180 Hz.

What cables do I need to connect this to my sound system?

You'll need Speakon-to-Speakon speaker cables to connect from your amplifier or powered mixer to the subwoofer. The dual Speakon connectors allow pass-through wiring if you want to daisy-chain multiple subwoofers or connect a top speaker through the sub.

How does this compare to a 15" subwoofer for church sound?

The 18" driver in the Magma-118S reaches deeper (40 Hz vs typically 50+ Hz for 15" subs) and moves more air, making it better suited for contemporary worship music with synthesizers and electronic drums. The larger driver also provides more headroom for dynamic bass content without strain.

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