Short answer: the Rythmik FV18. It ranks #44 of 97 subwoofers by sound quality at $2220; the Harbottle Audio C24 L1 ranks #45 and costs $6244.50, so there is not much of a tradeoff to weigh.
What the Harbottle Audio C24 L1 offers: Published CEA-2010 specifications list 114.0 dB at 20 Hz and 121.3 dB through 40-80 Hz. The ported enclosure with 24” (610mm) driver has the headroom for demanding film bass in a large room. Watch for: The 899.9H x 722.1W x 512.1D mm cabinet and 63.0 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
What the Rythmik FV18 offers: Independent CEA-2010 testing records 114.3 dB at 20 Hz and 121.3 dB through 40-80 Hz. The ported, front enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room. Watch for: The 838.2H x 533.4W x 558.8D mm cabinet and 72.6 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Buy the Rythmik FV18. It ranks higher for sound quality than the Harbottle Audio C24 L1 and costs less, so there is no real case for the other one.
Specifications Side By Side
| Harbottle Audio C24 L1 | Rythmik FV18 | |
|---|---|---|
| Price | $6,244.50 | $2,220 |
| Ranked | #45 of 97 in Large Powered Home Subwoofers (Over 75 lbs) | #44 of 97 in Large Powered Home Subwoofers (Over 75 lbs) |
| Enclosure | ported | ported, front |
| Output SPL at 10 Hz | 94.0 dB | - |
| Output SPL at 12.5 Hz | 99.0 dB | 102.0 dB |
| Output SPL at 15 Hz | 106.0 dB | 109.5 dB |
| Output SPL at 20 Hz | 114.0 dB | 114.3 dB |
| Output SPL at 25 Hz | 116.0 dB | 117.6 dB |
| Output SPL at 31.5 Hz | 121.0 dB | 119.2 dB |
| Output SPL at 40 Hz | 121.1 dB | 120.4 dB |
| Output SPL at 50 Hz | 121.6 dB | 121.3 dB |
| Output SPL at 63 Hz | 121.6 dB | 121.7 dB |
| Output SPL at 80 Hz | 121.0 dB | 121.9 dB |
| Output SPL at 100 Hz | 121.0 dB | 122.4 dB |
| CEA-2010-A Average (40-80Hz) | 121.3 dB | 121.3 dB |
| Dimensions | 35.4"H x 28.4"W x 20.2"D (899.9 x 722.1 x 512.1 mm) | 33"H x 21"W x 22"D (838.2 x 533.4 x 558.8 mm) |
| Weight | 138.9 lbs / 63.0 kg | 160.1 lbs / 72.6 kg |
| Cabinet Color | black, white, red, blue | black |
| Country | Canada | United States |
| Measurement Source | Manufacturer | Data-bass |
| Drivers | 24" (610mm) driver | 18" (457mm) driver |
| Output SPL at 125 Hz | - | 121.9 dB |
| Warranty | - | 5/3 |
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- Rythmik FV18 vs HSU Research VTF-3 MK5 HP
- SVS PB16-Ultra vs Arendal 1723 Subwoofer 2V
Prices on this page were last checked September 8, 2026 at 6:02 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
Harbottle Audio C24 L1: $6,244.50 eBay
Pros: Published CEA-2010 specifications list 114.0 dB at 20 Hz and 121.3 dB through 40-80 Hz. The ported enclosure with 24” (610mm) driver has the headroom for demanding film bass in a large room.
Cons: The 899.9H x 722.1W x 512.1D mm cabinet and 63.0 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Full Harbottle Audio C24 L1 review and specifications →
| CEA-2010-A Average (40-80Hz) | 121.3 dB |
|---|---|
| Cabinet Color | black, white, red, blue |
| Country | Canada |
| Dimensions | 35.4"H x 28.4"W x 20.2"D (899.9 x 722.1 x 512.1 mm) |
| Drivers | 24" (610mm) driver |
| Enclosure | ported |
| Measurement Source | Manufacturer |
| Output SPL at 10 Hz | 94.0 dB |
| Output SPL at 12.5 Hz | 99.0 dB |
| Output SPL at 15 Hz | 106.0 dB |
| Output SPL at 20 Hz | 114.0 dB |
| Output SPL at 25 Hz | 116.0 dB |
| Output SPL at 31.5 Hz | 121.0 dB |
| Output SPL at 40 Hz | 121.1 dB |
| Output SPL at 50 Hz | 121.6 dB |
| Output SPL at 63 Hz | 121.6 dB |
| Output SPL at 80 Hz | 121.0 dB |
| Output SPL at 100 Hz | 121.0 dB |
| Weight | 138.9 lbs / 63.0 kg |
- Links
- Reviews, Comparisons and Sound Samples
Rythmik FV18: $2,220 eBay
Pros: Independent CEA-2010 testing records 114.3 dB at 20 Hz and 121.3 dB through 40-80 Hz. The ported, front enclosure with 18” (457mm) driver has the headroom for demanding film bass in a large room.
Cons: The 838.2H x 533.4W x 558.8D mm cabinet and 72.6 kg mass make this a serious placement and moving commitment. Ported output does not solve room modes, so careful placement and calibration remain essential.
Full Rythmik FV18 review and specifications →
| CEA-2010-A Average (40-80Hz) | 121.3 dB |
|---|---|
| Cabinet Color | black |
| Country | United States |
| Dimensions | 33"H x 21"W x 22"D (838.2 x 533.4 x 558.8 mm) |
| Drivers | 18" (457mm) driver |
| Enclosure | ported, front |
| Measurement Source | Data-bass |
| Output SPL at 12.5 Hz | 102.0 dB |
| Output SPL at 15 Hz | 109.5 dB |
| Output SPL at 20 Hz | 114.3 dB |
| Output SPL at 25 Hz | 117.6 dB |
| Output SPL at 31.5 Hz | 119.2 dB |
| Output SPL at 40 Hz | 120.4 dB |
| Output SPL at 50 Hz | 121.3 dB |
| Output SPL at 63 Hz | 121.7 dB |
| Output SPL at 80 Hz | 121.9 dB |
| Output SPL at 100 Hz | 122.4 dB |
| Output SPL at 125 Hz | 121.9 dB |
| Warranty | 5/3 |
| Weight | 160.1 lbs / 72.6 kg |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons