On-Stage SSA21 Subwoofer Adapter

On-Stage SSA21 Subwoofer Adapter

Adapt an M20 speaker stand shaft to connect to virtually any subwoofer mounting socket with our SSA21 Subwoofer Adapter. To increase speaker mount compatibility, this adapter features a 1 3/8-inch mounting pole with a removable M20-threaded lug that enables a proper fit for virtually any socket including shallow M20, recessed M20, 1 3/8-inch cup, and 1 3/8-inch cup with M20. Its heavy-duty construction ensures sturdy support for reliable speaker placement.

• Adapts M20-threaded speaker poles to connect to unthreaded 1 3/8"-inch mounting sockets
• Removable threaded lug enables connection to any M20-threaded mounting socket
• Solid steel construction for dependable speaker support

SPECIFICATIONS

• Application: M20 Subwoofer Adapter with removable M20
• Upper Adapter: Accepts male M20
• Lower Adapter: Tapered to 1 3/8-inch with removable M20 to fit all subwoofers on the market
• Includes: key for M20 lug removal
• Construction: Steel
• Color: Black

We are Chuck Levin's Washington Music Center

Since 1958, Chuck Levin’s Washington Music Center has been the trusted destination for musicians and audio professionals across Maryland, Virginia, and Washington, D.C. Family-owned and operated, our legendary music store delivers Everything in Music®—from instruments and recording gear to pro audio, rentals, and repair services.

Our team of musicians and industry experts lives and breathes gear, helping you build the perfect setup for your next performance, studio session, or installation. As an authorized dealer for top brands, we also offer our award-winning CHUCKSCLUSIVE line—exclusive, limited-edition instruments and collaborations recognized with the NAMM Top 100 Dealer Innovation Award for redefining what a music retail experience can be.

Chuck Levin’s isn’t just a store—it’s a community built by players, engineers, and creators who share a lifelong passion for sound. Stop by our legendary Wheaton, MD showroom or contact us anytime for expert advice, product questions, or the best possible deal on your next piece of gear.