Monoprice SW-12 12" Powered Subwoofer
- 400 watts RMS, 600 watts peak
- 12 inch front-firing woofer
- Down-firing port, ported design
- Variable phase control and variable low pass filter
- RCA and speaker-level inputs
- Remote control and bass boost
- 25 pounds, 14.9 x 18.3 x 19.1 inches
- Floor standing placement
Last refreshed Jun 20, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A powered subwoofer with a large woofer for adding bass to a home theater or music system. It is wired only, and the listing gives a single frequency figure with no full range.
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ASIN: B08Q74NX8DModel: SW-12Category: Subwoofers
Overview
Monoprice built this subwoofer around a front-firing woofer and a down-firing port, with an onboard amplifier that makes it a self-powered unit. Phase and cutoff adjustments are part of the design.
Amplifier output and adjustable phase and filter controls are the reason to buy, since they let the sub blend with existing speakers. The limits: it connects by wire only; the listing does not describe where the controls are on the cabinet.
Who it's for
Room-sized stereo and surround setups with an open outlet and a spot for a floor-standing box suit this unit, and the adjustments make matching it to existing speakers easier. Small apartments, desk systems and buyers who need wireless placement should choose a smaller or wireless model.
Pros and cons
- High amplifier output
- Adjustable phase and low pass filter
- Bass boost feature
- RCA and speaker-level inputs
- Wired connection only
- Control layout not described
- Large floor-standing cabinet
- Warranty length unclear
Performance notes
A ported cabinet uses airflow through the port to reinforce low frequencies, which raises output near the tuning point. The down-firing port needs clearance beneath the box, and placement near walls or corners adds bass further. The phase control aligns the sub's timing with the other speakers, and the low pass filter sets where the sub hands off to them.
Specifications
| Brand | Monoprice |
|---|---|
| Model | SW-12 |
| Dimensions & fit | |
| Subwoofer Diameter | 12 incheshigher than 65% of 24 subwoofers |
| Item weight | 25 pounds |
| Item Dimensions D x W x H | 14.9 x 18.3 x 19.1 inches |
| Capacity & performance | |
| Speaker Maximum Output Power | 400 watts RMS, 600 watts peakhigher than 57% of 31 subwoofers |
| Power & efficiency | |
| Power Source | Corded electric |
| Compatibility & installation | |
| Subwoofer Connectivity Technology | Wired |
| Connectivity Protocol | RCA, speaker level |
| Mounting Type | Floor standing |
| Warranty & support | |
| Warranty Type | Limited |
| Other details | |
| Frequency Response | 150 Hz |
| Control Type | Remote |
| Speaker Type | Bass reflex with down-firing port |
| Additional Features | Variable phase control, variable low pass filter, bass boost |
Closest rivals on specs
Behringer EUROLIVE B1200D-PRO Active PA Subwoofer 12 Inch- Speaker Maximum Output Power 600 vs 500 watts (+20%)
Alpine W12S4 Subwoofer 12 Inch- Speaker Maximum Output Power 600 vs 500 watts (+20%)
Frequently asked questions
Is the Monoprice SW-12 wireless?
No. The connection is wired, with RCA and speaker-level inputs.
Is the Monoprice SW-12 a complete speaker system?
No. The contents list a powered subwoofer only, so it needs main speakers and a source.
Does the Monoprice SW-12 work in a car?
The compatible vehicle field says car, but the title and description describe a floor-standing home theater subwoofer powered from an outlet, so ignore that entry.