250W Mono High Current Class A/B Subwoofer Amplifier - SMP250

Quick Overview

If you're looking for a subwoofer amplifier, OSD Audio has you covered. The SMP250 Mono Subwoofer Amp features variable low-pass crossover, easily accessible volume control and a low-frequency effect input. It's designed for use with higher wattage passive subwoofers so you can tighten the level of the bass signal. You can even use the high-pass ins and outs to send the signal back into your sound system.


OSD Audio’s SMP250 Mono Subwoofer Amp gives passive subwoofers up to 250 watts of power so you can experience all the crashes, crunches and car chases with spine-tingling exhilaration. Designed for use with higher wattage passive subwoofers such as in-wall subs that require external power, the SMP250 Mono Subwoofer provides stable power and enhances the low frequency sound effects. Moderately priced with high-end features, this sub amp includes a variable high cut filter that routes higher frequencies to main speakers so subs can concentrate on the low frequency sound effects they are designed to handle. The result is bass that does not sound muddy or overly thumpy but rather crisp and detailed. You’ll immediately feel and hear the difference. Other features include a back panel adjustable gain and volume control limiter to protect the woofers as well as low-level and high-level pass-through input/outputs to cover newer and old school sound systems.

Why Do You Need Subwoofer Amp?
If you have a powered subwoofer, you don’t. A powered subwoofer has its own internal amplifier which is why they are extremely heavy to lift. A passive subwoofer is simply a woofer or woofers in an enclosure that is designed to handle low frequencies but does not have an internal amplifier, which is why they are not heavy to lift. In-wall subs are most commonly passive. After all, it’s not so easy to install a 100-pound sub inside a wall. That’s where an amp like the SMP250 Mono Subwoofer Amp comes into play. This amp not only adds necessary power but the high-cut filter keeps low bass away from your surround speakers, which in turn gives you much cleaner highs and midrange. This subwoofer amp does much more than supply power. It also improves the overall sound quality of your entire surround sound system.

What Is A Class A/B Amplifier?
In home theater, Class A/B are the most common because they combine the efficiency of Class B with the sound quality of Class A amps. A Class A amplifier uses the input signal 100% of the time, which means that the output signal to your sub matches the input signal from your receiver. The result is virtually no clipping or distortion. Sounds perfect, right? The downside is that Class A amplifiers run very hot because the transistors are working all the time. Class B amplifiers only amplify half of the input signal which creates some distortion but these amps are far more efficient than Class A amplifiers and run a lot cooler. A Class A/B amp combines the best of A and B, so distortion is lower yet efficiency is high so sound quality is truly maximized.

Additional Information

Model Number OSD-SMP250
  • 250W Peak Power / 150W Continuous RMS Single Channel Mono
  • Front-mounted Power Meter
  • Easily accessible volume control
  • Auto Power On/Off
  • Low frequency effect input (LFE)
  • Dual Voltage 110/220V
  • Variable High Cut Filter 30Hz – 150Hz; front panel Knob
  • Additional Front Panel Controls: Phase Switch and Volume Control
  • Choice of Signal Level Input or LFE (Low Frequency Effects)
  • Three Turn on Choices: Music Sensing, Manual On or hard 12 Volt Trigger
  • Back Panel Adjustable Gain /Volume Control Limiter
  • Both Signal (Low Level) and Speaker (High Level) Pass through Input/outputs
  • Maximum Output: Single 8-ohm Sub Woofers or Single 8 ohm DVC Woofer (See IWS8 or IWS-88)
  • 110/220V switchable
  • 2-Year Warranty
Condition New
UPC 810281014098