Mackie SPM400

The SPM400 speaker pole lets you mount a compatible loudspeaker on top of a subwoofer — e.g. from Mackie’s DRM, SR, or Thump series — using a secure M20 threaded mount, creating a compact full-range PA system with minimal footprint. 
It makes a neat, all-in-one stack: subwoofer below, top speaker above — ideal for live gigs, mobile PA, rentals, clubs, venues, or any place where space and setup speed matter.
Key Specs & Features
Speaker-mount type: M20 threaded pole, for stable and secure attachment to subwoofer base. 
Compatible with: subwoofers such as DRM18S, plus any top speaker with a standard pole-mount socket. 
Dimensions: approx. 2 in × 2 in × 54.7 in (when extended) — about 1390 mm. 
Pole weight: ~ 3.5 lb (≈ 1.6 kg) — light enough to handle, sturdy enough for live rigging. mackie.com+1
Load capacity: sufficient for typical powered speakers/subwoofers in the compatible range.
Use-cases / Benefits
Build a compact, full-range PA system using sub + top speaker stack — great for live shows, events, rentals, venues, or mobile rigs.
Save stage/venue space — one stack instead of multiple stands; cleaner setup and faster rig in/out.
Stable and secure mounting thanks to M20 threaded design — reduces risk of wobbling or tipping, even when transporting or setting up frequently.
Flexible & simple setup — ideal when you want pro-level sound without bulky, complicated rack or stand systems.