Short answer: the Klipsch RP-1600SW, if you are buying new. The Monoprice Monolith 15 THX Ultra measures as well as it (#66 vs #67 of 143 subwoofers, 4.2/5 vs 4.2/5) but is discontinued, so only consider it used; the Klipsch RP-1600SW is still sold new at $1,999.99.
The case for the Monoprice Monolith 15 THX Ultra: A THX Ultra certified 15 inch ported subwoofer with strong deep bass for home theaters, a good buy used. The catch: The 680.7H x 449.6W x 701.0D mm cabinet and 128.5 lbs (58.3 kg) mass make this a serious placement and moving commitment.
The case for the Klipsch RP-1600SW: A 16 inch ported subwoofer with deep, strong bass for large home theaters, still sold new. Watch for: The 594.1H x 596.9W x 694.7D mm cabinet and 110.9 lbs (50.3 kg) mass make this a serious placement and moving commitment.
Buy the Klipsch RP-1600SW, since the Monoprice Monolith 15 THX Ultra is discontinued and only worth hunting down used.
Still deciding? The full Subwoofers rankings cover every ranked option.
Prices on this page were last checked November 14, 2026 at 6:17 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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| Monoprice Monolith 15 THX Ultra | Klipsch RP-1600SW | |
|---|---|---|
| Price | $1,999 Discontinued | $1,999.99 |
| Ranked | #66 of 143 in Large Home Subwoofers (Over 75 lbs) | #67 of 143 in Large Home Subwoofers (Over 75 lbs) |
| Enclosure | ported, front | ported, front |
| Output SPL at 12.5 Hz | 90.0 dB | 101.0 dB |
| Output SPL at 15 Hz | 100.8 dB | 108.5 dB |
| Output SPL at 20 Hz | 110.0 dB | 112.5 dB |
| Output SPL at 25 Hz | 115.6 dB | 116.3 dB |
| Output SPL at 31.5 Hz | 118.0 dB | 120.5 dB |
| Output SPL at 40 Hz | 122.0 dB | 121.5 dB |
| Output SPL at 50 Hz | 121.0 dB | 120.6 dB |
| Output SPL at 63 Hz | 120.0 dB | 120.0 dB |
| Output SPL at 80 Hz | 119.0 dB | 119.6 dB |
| Output SPL at 100 Hz | 119.0 dB | 118.8 dB |
| Output SPL at 125 Hz | 118.0 dB | 118.5 dB |
| CEA-2010-A Average (40-80Hz) | 120.5 dB | 120.4 dB |
| Dimensions | 26.8”H x 17.7”W x 27.6”D (680.7 x 449.6 x 701.0 mm) | 23.4”H x 23.5”W x 27.4”D (594.1 x 596.9 x 694.7 mm) |
| Weight | 128.5 lbs (58.3 kg) | 110.9 lbs (50.3 kg) |
| Warranty | 5 | 5 |
| Cabinet Color | black | black |
| Country | United States | United States |
| Measurement Source | ErinsAudioCorner | Audioholics |
| Drivers | 15” (381mm) driver | 16” (406mm) driver |
| Inputs | XLR, RCA | - |
| XLR Input | Yes | - |
| RCA Input | Yes | - |
| TRS Input | No | - |
| Optical Input | No | - |
| Coaxial Input | No | - |
| USB Input | No | - |
| HDMI Input | No | - |
| AES Input | No | - |
| Aux Input | No | - |
| Output SPL at 10 Hz | - | 85.2 dB |
Where the Ratings Come From
- Monoprice Monolith 15 THX Ultra: reviews by Erin’s Audio Corner.
- Klipsch RP-1600SW: manufacturer specifications and listening comparisons; no independent measurement has been published yet.
This comparison is generated from the ratings, specifications and measurements on each product’s own page, and it updates when that data changes. How we rank explains how each rating is decided.
Related Speaker Comparisons
How Monoprice Monolith 15 THX Ultra compares with other leading options: