29Hz LF Limit,
Narrow dimension, to fit in cramped spaces < 12in (300mm)
High 4000W Power handling, High Efficiency 101dB
Low distortion, Low thermal compression
Stackable, Cardioid Capable


The SB212i-LO is an ultra low profile, high efficiency, high impact sub-bass loudspeaker with exceptionally high power handling. This incredibly capable sub is ideally used when an excellent sub performance is required, yes space constraints are tight. It provides high impact, high sensitivity, low thermal compression and incredibly low distortion out of a compact package, even at the highest drive levels. These combined properties deliver the characteristic RMS-Acoustics sonic qualities of Impact, precision, and musicality.

The SB212i-LO is one of the recommended subwoofers for use with the C coaxial series and is also well suited for use with the VC system family from RMS-Acoustics. The SB212i-LO can be deployed in standard or cardioid configurations, with dedicated presets for each configuration, in flown, or stacked configurations.

The SB212i-LO features two long excursion, high power handling 12” cone loudspeakers mounted in a mechanically and acoustically optimized bass reflex cabinet with laminar venting. Port turbulence is virtually eliminated, and high drive level distortion is minimized via large, flared, symmetrical laminar venting. It operates from 29 Hz to 100 Hz when used as a general ground support subwoofer.

The SB212i-LO enclosure was designed with installation in mind. The compact ultra low profile allows the SB212i-LO to fit easily under stages, up tight to ceilings, and between standard framing for flush mount installations.

The enclosure is constructed of premium birch hardwood plywood to ensure maximum acoustical and mechanical integrity. It is then coated with a weather and wear resistant textured urethane hybrid finish. Optional rigging components are weather and corrosion protected with a heat cured epoxy powder coated finish or zinc plating with passivation.

The optimum processed loudspeaker solution for the RMS-Acoustics SB subwoofer family are RMS-ACOUSTICS series of processed amplifiers. Additionally, the Linea Research C and M series amplifiers, with proprietary presets provided by RMS-ACOUSTICS are supported.


System Sensitivity (1w, 1m)^1 101dB (2.1V @ 100Hz, 1W 1m)
Frequency Response(-10dB) 29Hz-150Hz 0dB point taken at 60Hz, processed
Frequency Response (±3dB) 36Hz-150Hz 0dB point taken at 60Hz, processed
Maximum SPL Continuous (1m)^2 130dB
Maximum SPL Peak (1m) 136dB
Long Term Power Rating (IEC)^3 LF 1600W Continuous, 3200W Program, 6400W Peak 100Hr
Long Term Power Rating (AES)^4 LF 2000W (4000W Peak) 2 hr
Maximum Input Voltage LF 89.5 V RMS (2 hrs), 127V Peak 4 ohm load
Nominal Coverage Pattern Omni directional, variable directivity with cardioid presets and custom modification
System Crossover Proprietary DSP via RMS-ACOUSTICS and  Linea Research processing platforms
Transducer Specifications SPKR-12-0007 LF Driver - 12” low frequency cone loudspeaker with 4” voice coil, shorting ring and high performance convective cooling technology
Impedance LF 4 Ohm, speakers internally wired in parallel 1+ 1-
Input Connectors Dual Neutrik NL4MP Connectors, w jump and pass thru
Enclosure Materials 18mm Birch Hardwood Ply 1.3mm layers
Grill Materials None
Finishes Black finish (Standard) Polyurethane textured spray
Additional Finishes available - See Options Below
Suspension and Mounting Optional Eye Bolt Mounting (Upcharge)
Flown Array Maximum Maximum Array height dependent or rigging system employed. Standard and Cardioid flown arrays possible. Contact support at [email protected] to discuss further.
Rigging Hardware
Dimensions 36.2” W x 28” D x 11.7” H  (920 mm x 712 mm x 298 mm)        11.5" H ( 293 mm) with feet removed
Weight 115 Lbs (52.3 kg) Net   Shipping weight 125Lb (56.8 kg)
Finish Options -W (White) -C (Custom Color) Upcharges apply
Optional Accessories
Free field, semi anechoic conditions.  To compare with half space measurements, add 6dB to maximum output specifications.
1. Full Space, 4pi conditions
2. Measured Maximum SPL, based on power compression observation of 3dB
3. IEC Shaped pink noise with 6dB Crest Factor
4. AES Standard AES2-2012, one decade pink noise with 6dB Crest factor within device’s applicable operating band, free air. Standard AES 2 hr rating are specific for low frequency transducers.