HSU Research ULS-15 MK2 vs Klipsch R-121SW

Last updated: September 19, 2026

Short answer: the HSU Research ULS-15 MK2 if bass quality is the priority, the Klipsch R-121SW if it is price. The HSU’s sealed cabinet delivers tight, accurate bass with low bloat and ranks #3 of 145 subwoofers, at $999. The Klipsch ranks #95 but costs $750 less, and its 12-inch spun-copper driver with a 200W RMS amplifier gives controlled, musical bass with minimal distortion.

HSU Research ULS-15 MK2 vs Klipsch R-121SW

What the HSU Research ULS-15 MK2 gets right: Sealed design delivers tight, accurate bass with low bloat.

On the Klipsch R-121SW side: 12-inch spun-copper driver with 200W RMS delivers controlled, musical bass with minimal distortion.

Buy the HSU Research ULS-15 MK2 when sound quality outweighs the price for you, and the Klipsch R-121SW when the price outweighs sound quality instead.

Still deciding? The full Subwoofers rankings cover every ranked option.

Buy the HSU Research ULS-15 MK2 at HSU Research ($999.00) →Buy the Klipsch R-121SW at Amazon ($249.00) →

Specifications Side By Side

HSU Research ULS-15 MK2 Klipsch R-121SW
Price$1,035$249.00
Ranked#3 of 145 in Medium Home Subwoofers (30-75 lbs)#95 of 145 in Medium Home Subwoofers (30-75 lbs)
Enclosuresealedported, rear
Output SPL at 12.5 Hz93.7 dB-
Output SPL at 15 Hz98.0 dB90.7 dB
Output SPL at 20 Hz102.4 dB96.0 dB
Output SPL at 25 Hz107.7 dB98.4 dB
Output SPL at 31.5 Hz113.4 dB102.3 dB
Output SPL at 40 Hz118.3 dB108.2 dB
Output SPL at 50 Hz120.8 dB112.4 dB
Output SPL at 63 Hz121.2 dB112.9 dB
Output SPL at 80 Hz121.1 dB111.3 dB
Output SPL at 100 Hz120.7 dB109.9 dB
Output SPL at 125 Hz120.7 dB108.3 dB
CEA-2010-A Average (40-80Hz)120.3 dB111.2 dB
Dimensions19"H x 18"W x 19.5"D (482.6 x 457.2 x 495.3 mm)16.6"H x 16"W x 19.7"D (421.6 x 406.4 x 500.4 mm)
Weight65 lbs (29.5 kg)35.1 lbs (15.9 kg)
Warranty7/2(+3)5/2
Cabinet Colorblack, woodblack
CountryUnited StatesUnited States
Measurement SourceAudioholicsAudioholics
Frequency Response20-200Hz, ±1dB28-120Hz
Amplifier Power600W RMS / 2000W peak200W RMS
Crossover Frequency30-90Hz adjustable-
Phase Control0°-180°-
FeaturesQ control, sealed subwoofer, EQ1/EQ2 modes-
Drivers15" (381mm) driver12" (305mm) driver
Buy the HSU Research ULS-15 MK2 at HSU Research ($999.00) →Buy the Klipsch R-121SW at Amazon ($249.00) →

How HSU Research ULS-15 MK2 compares with other leading options:

Prices on this page were last checked September 23, 2026 at 11:24 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.

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The Two Speakers In Full

HSU Research ULS-15 MK2: $1,035 HSU Research eBay

HSU Research ULS-15 MK2 ranking card

Pros: Sealed design delivers tight, accurate bass with low bloat. 600W BASH amplifier. 30% less expensive and 20 lbs lighter than predecessor. Easy integration with Q and EQ controls. Great value in the 15” sub market.

Notes: Price includes shipping

Full HSU Research ULS-15 MK2 review and specifications →

Amplifier Power600W RMS / 2000W peak
CEA-2010-A Average (40-80Hz)120.3 dB
Cabinet Colorblack, wood
CountryUnited States
Crossover Frequency30-90Hz adjustable
Dimensions19"H x 18"W x 19.5"D (482.6 x 457.2 x 495.3 mm)
Drivers15" (381mm) driver
Enclosuresealed
FeaturesQ control, sealed subwoofer, EQ1/EQ2 modes
Frequency Response20-200Hz, ±1dB
Measurement SourceAudioholics
Output SPL at 12.5 Hz93.7 dB
Output SPL at 15 Hz98.0 dB
Output SPL at 20 Hz102.4 dB
Output SPL at 25 Hz107.7 dB
Output SPL at 31.5 Hz113.4 dB
Output SPL at 40 Hz118.3 dB
Output SPL at 50 Hz120.8 dB
Output SPL at 63 Hz121.2 dB
Output SPL at 80 Hz121.1 dB
Output SPL at 100 Hz120.7 dB
Output SPL at 125 Hz120.7 dB
Phase Control0°-180°
Warranty7/2(+3)
Weight65 lbs (29.5 kg)
Check current price at HSU Research ($999.00) →Search eBay for HSU Research ULS-15 MK2 →

Klipsch R-121SW: $249.00 Amazon eBay

Klipsch R-121SW ranking card

Pros: 12-inch spun-copper driver with 200W RMS delivers controlled, musical bass with minimal distortion. Front-firing design maximizes placement flexibility. Excellent value with exceptional bang-for-buck.

Full Klipsch R-121SW review and specifications →

Amplifier Power200W RMS
CEA-2010-A Average (40-80Hz)111.2 dB
Cabinet Colorblack
CountryUnited States
Dimensions16.6"H x 16"W x 19.7"D (421.6 x 406.4 x 500.4 mm)
Drivers12" (305mm) driver
Enclosureported, rear
Frequency Response28-120Hz
Measurement SourceAudioholics
Output SPL at 15 Hz90.7 dB
Output SPL at 20 Hz96.0 dB
Output SPL at 25 Hz98.4 dB
Output SPL at 31.5 Hz102.3 dB
Output SPL at 40 Hz108.2 dB
Output SPL at 50 Hz112.4 dB
Output SPL at 63 Hz112.9 dB
Output SPL at 80 Hz111.3 dB
Output SPL at 100 Hz109.9 dB
Output SPL at 125 Hz108.3 dB
Warranty5/2
Weight35.1 lbs (15.9 kg)
Check current price at Amazon ($249.00) →Search eBay for Klipsch R-121SW →