Short answer: the Rythmik F18 for better sound quality, the SVS SB13-Plus for the lower price. The Rythmik F18 ranks #69 of 110 subwoofers at $2344. The SVS SB13-Plus ranks #108 at $1399, $945 cheaper.
What the Rythmik F18 offers: Independent CEA-2010 testing records 106.2 dB at 20 Hz and 119.5 dB through 40-80 Hz. The sealed enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room. Watch for: The 520.7H x 520.7W x 533.4D mm cabinet and 52.2 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
What the SVS SB13-Plus offers: Independent CEA-2010 testing records 92.3 dB at 20 Hz and 108.1 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with 13” (330mm) driver delivers substantial upper-bass output for movie effects and music. Watch for: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 431.8H x 431.8W x 457.2D mm cabinet and 43.1 kg mass still require deliberate placement and calibration.
Buy the Rythmik F18 if sound quality matters more than the price. Buy the SVS SB13-Plus if the price matters more than sound quality.
Skip the SVS SB13-Plus if sound quality matters to you. It ranks near the bottom of the 110 subwoofers.
Looking for alternatives? See the complete Subwoofers rankings.
Specifications Side By Side
| Rythmik F18 | SVS SB13-Plus | |
|---|---|---|
| Price | $1,850 | $1399 |
| Ranked | #69 of 110 in Large Home Subwoofers (Over 75 lbs) | #108 of 110 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | sealed | sealed |
| Output SPL at 10 Hz | 93.7 dB | - |
| Output SPL at 12.5 Hz | 97.4 dB | - |
| Output SPL at 15 Hz | 102.0 dB | - |
| Output SPL at 20 Hz | 106.2 dB | 92.3 dB |
| Output SPL at 25 Hz | 110.9 dB | 97.2 dB |
| Output SPL at 31.5 Hz | 114.3 dB | 97.2 dB |
| Output SPL at 40 Hz | 117.1 dB | 108.1 dB |
| Output SPL at 50 Hz | 119.1 dB | 108.1 dB |
| Output SPL at 63 Hz | 120.5 dB | 108.1 dB |
| Output SPL at 80 Hz | 121.2 dB | - |
| Output SPL at 100 Hz | 121.4 dB | - |
| Output SPL at 125 Hz | 121.4 dB | - |
| CEA-2010-A Average (40-80Hz) | 119.5 dB | 108.1 dB (avg of 3/4 bands) |
| Dimensions | 20.5"H x 20.5"W x 21"D (520.7 x 520.7 x 533.4 mm) | 17"H x 17"W x 18"D (431.8 x 431.8 x 457.2 mm) |
| Weight | 115.1 lbs (52.2 kg) | 95 lbs (43.1 kg) |
| Warranty | 5/3 | 5 |
| Cabinet Color | black | - |
| Country | United States | United States |
| Measurement Source | Data-bass | Brent Butterworth |
| Drivers | 18" (457mm) driver | 13" (330mm) driver |
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Prices on this page were last checked September 16, 2026 at 12:41 AM 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
Rythmik F18: $1,850 Rythmik Audio eBay
Pros: Independent CEA-2010 testing records 106.2 dB at 20 Hz and 119.5 dB through 40-80 Hz. The sealed enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room.
Cons: The 520.7H x 520.7W x 533.4D mm cabinet and 52.2 kg mass make this a serious placement and moving commitment. A sealed cabinet still needs careful placement and calibration to avoid room-mode peaks.
Full Rythmik F18 review and specifications →
| CEA-2010-A Average (40-80Hz) | 119.5 dB |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 20.5"H x 20.5"W x 21"D (520.7 x 520.7 x 533.4 mm) |
| Drivers | 18" (457mm) driver |
| Enclosure | sealed |
| Measurement Source | Data-bass |
| Output SPL at 10 Hz | 93.7 dB |
| Output SPL at 12.5 Hz | 97.4 dB |
| Output SPL at 15 Hz | 102.0 dB |
| Output SPL at 20 Hz | 106.2 dB |
| Output SPL at 25 Hz | 110.9 dB |
| Output SPL at 31.5 Hz | 114.3 dB |
| Output SPL at 40 Hz | 117.1 dB |
| Output SPL at 50 Hz | 119.1 dB |
| Output SPL at 63 Hz | 120.5 dB |
| Output SPL at 80 Hz | 121.2 dB |
| Output SPL at 100 Hz | 121.4 dB |
| Output SPL at 125 Hz | 121.4 dB |
| Warranty | 5/3 |
| Weight | 115.1 lbs (52.2 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Independently measured by Data-bass; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
- Rythmik F18 vs Perlisten Audio R212s
- Rythmik F18 vs Monoprice Monolith M15-S
- Rythmik F18 vs Monoprice Monolith M-15 V2
- Rythmik F18 vs SVS PB-4000
- Rythmik F18 vs HSU Research VTF-3 MK5 HP
- Rythmik F18 vs HSU Research VTF-15H MK2
- Rythmik F18 vs Rythmik FV15HP
- Rythmik F18 vs HSU Research VTF-3 MK3
- See all 24 comparisons
SVS SB13-Plus: $1399 eBay
Pros: Independent CEA-2010 testing records 92.3 dB at 20 Hz and 108.1 dB (avg of 3/4 bands) through 40-80 Hz. The sealed enclosure with 13” (330mm) driver delivers substantial upper-bass output for movie effects and music.
Cons: Deep-bass output is more limited than the strong 40-80 Hz result suggests, so it is not the right choice when the lowest movie effects are the priority. The 431.8H x 431.8W x 457.2D mm cabinet and 43.1 kg mass still require deliberate placement and calibration.
Full SVS SB13-Plus review and specifications →
| CEA-2010-A Average (40-80Hz) | 108.1 dB (avg of 3/4 bands) |
|---|---|
| Country | United States |
| Dimensions | 17"H x 17"W x 18"D (431.8 x 431.8 x 457.2 mm) |
| Drivers | 13" (330mm) driver |
| Enclosure | sealed |
| Measurement Source | Brent Butterworth |
| Output SPL at 20 Hz | 92.3 dB |
| Output SPL at 25 Hz | 97.2 dB |
| Output SPL at 31.5 Hz | 97.2 dB |
| Output SPL at 40 Hz | 108.1 dB |
| Output SPL at 50 Hz | 108.1 dB |
| Output SPL at 63 Hz | 108.1 dB |
| Warranty | 5 |
| Weight | 95 lbs (43.1 kg) |
- Links
- 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
- SVS SB13-Plus vs Monoprice THX 121456
- SVS SB13-Plus vs BK Electronics Monolith-DF
- SVS SB13-Plus vs RSL (Rogersound Labs) Speedwoofer 12S
- SVS SB13-Plus vs HSU Research VTF-3 MK3
- SVS SB13-Plus vs SVS PB-4000
- SVS SB13-Plus vs HSU Research VTF-3 MK5 HP
- SVS SB13-Plus vs Rythmik FV15HP
- SVS SB13-Plus vs JTR Speakers Captivator 1400
- See all 16 comparisons