Klipsch Flexus Sub 100 vs KRK S8.4

Short answer: the Klipsch Flexus Sub 100. It ranks #22 of 73 subwoofers by sound quality, rated 3.4/5, at $279.99; the KRK S8.4 ranks #42, rated 3.3/5, and costs $369, which makes this an easy call rather than a real tradeoff.

The case for the Klipsch Flexus Sub 100: Independent CEA-2010 testing records 90.2 dB at 20 Hz and 109.1 dB (avg of 3/4 bands) through 40-80 Hz. Watch for: Only works with Klipsch Flexus soundbars, not as a standalone LFE sub.

The case for the KRK S8.4: The 8” studio subwoofer in KRK’s fourth generation, with a glass aramid woofer, a 109W Class D amplifier and a four-position crossover for pairing with Rokit monitors. Watch for: No independent measurements yet, so its output can’t be compared directly with ranked subwoofers; the rating is estimated from KRK’s measured 12S (117.1dB in the 40 to 80Hz CEA-2010 bands).

Buy the Klipsch Flexus Sub 100. It is rated higher for sound quality than the KRK S8.4 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.

About the ratings: the KRK S8.4’s rating is estimated from measured siblings and predecessors rather than its own measurements, with a likely range of 2.9 to 3.6, so this verdict could change once it is measured.

Looking for alternatives? See the complete Subwoofers rankings.

Specifications Side By Side

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• Klipsch Flexus Sub 100 vs MartinLogan Dynamo 700w

Prices on this page were last checked October 11, 2026 at 4:59 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

Klipsch Flexus Sub 100: $279.99 Amazon eBay

Same family: the Klipsch Flexus Sub 200 (larger subwoofer, estimated 3.8/5).

Pros: Independent CEA-2010 testing records 90.2 dB at 20 Hz and 109.1 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with a 10” driver suits a small room.

Cons: Only works with Klipsch Flexus soundbars, not as a standalone LFE sub. The 339.9H x 335.0W x 349.2D mm cabinet and 9.4 kg mass still need deliberate placement.

Full Klipsch Flexus Sub 100 review and specifications →

CEA-2010-A Average (40-80Hz)	109.1 dB (avg of 3/4 bands)
Country	United States
Dimensions	13.4”H x 13.2”W x 13.7”D (339.9 x 335.0 x 349.2 mm)
Drivers	10” (254mm) driver
Enclosure	sealed
Measurement Source	Brent Butterworth
Output SPL at 20 Hz	90.2 dB
Output SPL at 25 Hz	96.7 dB
Output SPL at 31.5 Hz	101.2 dB
Output SPL at 40 Hz	105.9 dB
Output SPL at 50 Hz	109.0 dB
Output SPL at 63 Hz	112.4 dB
Warranty	2/5
Weight	20.7 lbs (9.4 kg)

• Links
  • Official Klipsch Flexus Sub 100 Website
• Reviews, Comparisons and Sound Samples
  • Independently measured by Brent Butterworth; the published figures above come from this ASR subwoofer measurement thread.
• Head-to-Head Comparisons
  • Klipsch Flexus Sub 100 vs MartinLogan Dynamo 700w
  • Klipsch Flexus Sub 100 vs PreSonus Eris Sub 8BT
  • Klipsch Flexus Sub 100 vs Klipsch HD Theater 600
  • Klipsch Flexus Sub 100 vs ELAC SUB1010
  • Klipsch Flexus Sub 100 vs Monitor Audio BRW10
  • Klipsch Flexus Sub 100 vs SVS 3000 Micro
  • Klipsch Flexus Sub 100 vs SVS SB-1000 PRO
  • Klipsch Flexus Sub 100 vs Edifier T5s
  • See all 13 comparisons

KRK S8.4: $369.00 Estimated Amazon Sweetwater eBay

Same family: the KRK S10.4 (larger subwoofer, estimated 3.6/5) and the KRK S12.4 (larger subwoofer, estimated 3.9/5). See every KRK S Subwoofers generation.

Pros: The 8” studio subwoofer in KRK’s fourth generation, with a glass aramid woofer, a 109W Class D amplifier and a four-position crossover for pairing with Rokit monitors. Rated 34 to 133Hz (±3dB) and 113dB.

Cons: No independent measurements yet, so its output can’t be compared directly with ranked subwoofers; the rating is estimated from KRK’s measured 12S (117.1dB in the 40 to 80Hz CEA-2010 bands). An 8” driver gives up deep bass and output to larger subs.

Full KRK S8.4 review and specifications →

Released	2021 (5 years ago)
AES Input	No
Amplifier Power	109W Class D
Country	United States
Dimensions	11”H x 16.1”W x 11.5”D (279 x 410 x 292 mm)
Drivers	8” glass aramid composite woofer
Enclosure	ported
Frequency Response	34-133Hz ±3dB (manufacturer specified)
Maximum SPL	113dB (manufacturer specified)
Warranty	3
Weight	26.5 lbs (12 kg)
XLR Input	Yes

• Links
  • Official KRK S8.4 Product Page
• Reviews, Comparisons and Sound Samples
  • No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
• Head-to-Head Comparisons
  • KRK S8.4 vs Sonos Sub Mini
  • KRK S8.4 vs Sony Bravia Theater Sub 8