RSL Speedwoofer 12S Powered Subwoofer

  • Sunday, Jan 21, 2024

Foreword / YouTube Video Review

The review on this website is a brief overview and summary of the objective performance of this speaker. It is not intended to be a deep dive. More so, this is information for those who prefer “just the facts” and prefer to have the data without the filler.

However, for those who want more - a more detailed explanation of the objective performance, and my subjective evaluation (what I heard, what I liked, etc) - please watch the below video where I go more in-depth. Additionally, my CEA-2010 test results can be viewed directly via my Google Sheet here.


This subwoofer was loaned to me by RSL for testing and reviewing. I was not paid for this review nor did I receive anything in exchange. All my reviews are done on my own time with great care to give you all the best set of data and information I can provide in order to help you make a well-informed purchase decision. I offer this for free to all who are interested. In return, if you want to support this site please see the bottom of this review for ways you can support. It is greatly appreciated.

This subwoofer was also reviewed by James Larson at Audioholics (link) who provided a much more thorough written analysis of his subjective thoughts than I do in this writeup.

The current price for this subwoofer is $799 USD direct from the manufacturer:

Manufacturer Specs:

  • Frequency Response: Reference Mode (anechoic): 16 Hz-200 Hz ± 3db
  • Woofer: 12” 500+ watt rated woofer
  • 4 ohm nominal Impedance
  • Proprietary RSL Die-cast aluminum frame with dual spider integration
  • Klippel optimized linear magnet motor and matched suspension
  • High-Excursion FEA optimized design motor structure
  • Enclosure:
    • Scratch and fingerprint resistant textured matte finish
    • Front multi-segment LED display/indicator (Volume, Mute, & DSP MODE)
    • Display sleeps after ~10 sec. of inactivity
    • Rear-vented Compression Guide™ tuning with turbulent free slot port
    • Internal structural reinforcement (Side to side, front to back, and top cross-bracing)
    • ¾” thick MDF panels with dado reinforced joints plus corner bracing
    • Laminated 1” front woofer baffle
    • Internally optimized damping
    • Removable cloth grille
  • XDR Series Amplifier:
    • 500 watts RMS < 1% THD
    • 1550 watts peak
    • Patent Pending HSS™ Heat Sink/Shield Technology for greater thermal efficiency and capacity
    • DSP Modes – Reference, Music, Movies, Boundary (Rear LED indicator matches front display)
      • Reference – Minimal EQ processing, “natural” response for ideal transient performance
      • Music – Shelved response for extension, but with good upper bass impact
      • Movies – Enhanced output between 25-35Hz to augment low frequency content at low levels
      • Boundary – “Neighbor friendly”…Reduced lower frequencies to limit rumble through walls
  • Dimensions with Feet: H: 22 1/4” W: 18 7/8” D: 22 1/8”
  • Weight: 82 lbs.

Test Setup/Conditions:

All measurements - other than CEA-2010 - are provided as full-space anechoic @ 1 meter. This means frequency response, distortion and group delay were taken outdoors with the SPL referenced to a distance of 1 meter.

Frequency Response

The below shows the response in (4) different modes:

  • Reference
  • Movie
  • Music
  • Boundary

Reference provides the most linear response. Movie has a +2dB bump centered ~30Hz for enhanced bass effects. Music has a +1dB bump from about 30Hz to 60hz, centered around 45Hz to provide a bit more “punch”. Boundary mode decreases the output below ~40Hz due to the fact that placement near a wall will provide additional gain here.


Group Delay Comparison


Max SPL / Compression

The following test was ran at 3 input voltages:

  • 0.01 Volt RMS
  • 0.10 Volt RMS
  • 2.50 Volt RMS

The frequency response of each is provided below for comparison and understanding of the built-in limiting function that typically attenuates low frequency with higher SPL. In this case, compared to the blue line at 84dB, the max SPL is boosted ~1.5dB from 30Hz to 60Hz and attenuated approximately 3dB below 30Hz. In other words, there is approximately 3dB of compression between 84dB and 100dB average SPL (blue vs red).



Distortion at Max SPL


CEA-2010 Test Results

CEA-2010-A: Weighted and Limited Maximum Peak SPL (dB) SPL referenced to 2-meters in Half Space (2 pi)

Speaker 12.5 Hz 16 Hz 20 Hz 25 Hz 31.5 Hz 40 Hz 50 Hz 63 Hz 80 Hz 100 Hz
RSL Speedwoofer 12s No Test 104.4 109.3 110.9 112.5 113.4 113.4 113.0 113.1 112.2

Note: All the above data is from my spreadsheet which can viewed directly here.

Parting / Random Thoughts

This subwoofer is likely the best deal going today. The output capability, DSP features and overall performance are all at the top of the pack. Though, this subwoofer is rather large and heavy so consider that when comparing to other 12-inch subwoofers. You get significant more output capability with this compared to many of the “budget” $200-400 12-inch subwoofers available via Amazon but this subwoofer is quite a bit larger than many of them.

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