Short answer: the Monoprice SW-15. It ranks #14 of 212 subwoofers by sound quality, rated 4.1/5, at $499.99; the XTZ Sound 99 W12S ranks #61, rated 3.8/5, and costs $1,499, which makes this an easy call rather than a real tradeoff.
The case for the Monoprice SW-15: A big 15 inch subwoofer with powerful, punchy bass at a budget price, great for movies in a large room. The catch: Budget-tier design, ported room gain dependency, 66.1 lbs (30 kg) mid-size, and limited dynamic headroom.
The case for the XTZ Sound 99 W12S: A ported 12 inch subwoofer with a strong amplifier, phase control and EQ switches for tuning it to the room. Watch for: Deep output falls off sharply, with 86.5dB at 25Hz and 74.0dB at 20Hz, so it is weak for the lowest movie effects.
Buy the Monoprice SW-15. It is rated higher for sound quality than the XTZ Sound 99 W12S and costs less, which makes it the one to get unless you need something the other one does better.
Looking for alternatives? See the complete Subwoofers rankings.
A big 15 inch subwoofer with powerful, punchy bass at a budget price, great for movies in a large room.
A ported 12 inch subwoofer with a strong amplifier, phase control and EQ switches for tuning it to the room.
Prices on this page were last checked October 29, 2026 at 4:42 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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Specifications Side By Side
| Monoprice SW-15 | XTZ Sound 99 W12S | |
|---|---|---|
| Price | $499.99 | $1,499 |
| Ranked | #14 of 212 in Medium Home Subwoofers (30-75 lbs) | #61 of 212 in Medium Home Subwoofers (30-75 lbs) |
| Enclosure | ported, bottom | ported, rear |
| Output SPL at 15 Hz | 90.0 dB | - |
| Output SPL at 20 Hz | 101.2 dB | 74.0 dB |
| Output SPL at 25 Hz | 106.3 dB | 86.5 dB |
| Output SPL at 31.5 Hz | 111.2 dB | 97.7 dB |
| Output SPL at 40 Hz | 116.0 dB | 108.3 dB |
| Output SPL at 50 Hz | 120.2 dB | 114.9 dB |
| Output SPL at 63 Hz | 120.5 dB | 117.3 dB |
| Output SPL at 80 Hz | 119.5 dB | 117.4 dB |
| CEA-2010-A Average (40-80Hz) | 119.0 dB | 114.5 dB |
| Dimensions | 18.1”H x 21”W x 22.7”D (459.7 x 533.4 x 576.6 mm) | 19.6”H x 13.8”W x 15.7”D (499.1 x 349.8 x 400.0 mm) |
| Weight | 66.1 lbs (30.0 kg) | 67.2 lbs (30.5 kg) |
| Warranty | 1 | - |
| Cabinet Color | black | - |
| Country | United States | Sweden |
| Measurement Source | Audioholics | Ilkka Rissanen |
| Frequency Response | 30-150Hz (-10dB) | Not fully specified |
| Amplifier Power | 600W RMS / 800W peak | Not fully specified |
| Crossover Frequency | 40-150Hz, 18dB/octave | - |
| Phase Control | 0° or 180° | - |
| Inputs | Stereo line level and speaker level | - |
| Drivers | 15” (381mm) driver | 12” (305mm) driver |
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