---
product_id: 443893902
title: "SMP300 Class D Digital Subwoofer Amplifier Rated at 300W Max"
brand: "osd audio"
price: "154400 kr"
currency: ISK
in_stock: true
reviews_count: 5
category: "Osd Audio"
url: https://www.desertcart.is/products/443893902-smp300-class-d-digital-subwoofer-amplifier-rated-at-300w-max
store_origin: IS
region: Iceland
---

# Efficient Class D amp tech Compact 3" height design 300W max power output SMP300 Class D Digital Subwoofer Amplifier Rated at 300W Max

**Brand:** osd audio
**Price:** 154400 kr
**Availability:** ✅ In Stock

## Summary

> 🎵 Elevate your sound game with bass that’s as smart as it is powerful!

## Quick Answers

- **What is this?** SMP300 Class D Digital Subwoofer Amplifier Rated at 300W Max by osd audio
- **How much does it cost?** 154400 kr with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.is](https://www.desertcart.is/products/443893902-smp300-class-d-digital-subwoofer-amplifier-rated-at-300w-max)

## Best For

- osd audio enthusiasts

## Why This Product

- Trusted osd audio brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Cool & Compact:** Class D efficiency keeps it running cool in a sleek 3" tall chassis that fits anywhere.
- • **Smart Auto Standby:** Automatically powers down after 15 minutes of silence—energy smart and hassle-free.
- • **Powerful Bass Impact:** Delivers up to 300W peak power for deep, room-shaking bass that commands attention.
- • **Precision Sound Tuning:** Adjustable phase and low pass filter let you customize bass response for flawless integration.
- • **Universal Compatibility:** Seamlessly connects with all receivers via LFE, line-level, and speaker-level inputs—old or new.

## Overview

The OSD Audio SMP300 is a compact Class D digital subwoofer amplifier delivering up to 300W peak power. Designed for passive subwoofers, it features versatile inputs (LFE, line-level, speaker-level), adjustable phase and low pass filters for precise bass tuning, and a space-saving 3-inch height. Its efficient design ensures cool operation and energy-saving auto standby, making it the perfect upgrade for millennial professionals seeking immersive, customizable surround sound without bulk or complexity.

## Description

"If you’re ready to beef up the bass in your surround sound system, OSD Audio’s SMP300 is a Class D digital mono subwoofer delivers up to 300W of peak power to passive subwoofers so you can enjoy three dimensional surround sound from movie and music soundtracks. Designed for use with passive subwoofers such as in-wall subs that require external power, the SMP300 provides continuous, stable power but measures only 3” high so it can fit inside any equipment rack or cabinet. Moderately priced with high-end features, this compact sub amp includes variable low pass filter control for balanced and seamless sound quality as well as variable phase control for additional fine tuning. Multiple connection options include LFE input, line-level and speaker-level inputs to cover newer and old school source equipment.Variable Low Pass Filter and PhaseOSD Audio’s sub amp includes a front-panel variable low pass filter that allows you to adjust the upper frequency limit of the subwoofer to control the overlap of the subwoofer’s upper frequencies and the main speakers’ lower frequencies. This results in bass that complements the sound from the main speakers rather than overpowers. A front-panel variable phase control knob operates over a range from 0 degrees to 180 degrees and allows you to match the arrival times of the sound waves from the subwoofer and the main speakers. This fine-tuning results in bass that is less muddy or thumpy but rather smooth and detailed.Includes Class D Amp TechnologyThe SMP300 uses Class D digital amplifier technology that combines the best qualities of both Class A and B amp protocols into a highly efficient compact chassis that is ideal for budget-minded users who want a feature-rich digital sub amp that does not run hot or take up a lot of space. "

Review: It's a simple connect and play could not be any more simple. I hooked it up to a 10'' JBL Subwoofer and i am happy.
Review: Received this OSD SMP-100 subwoofer amp on January 9th 2020, after looking at different models this one made the most sense. After hooking it up and doing my tests this amp was exactly what I needed to include in my whole house audio system. This sub amp works excellent wired into my receiver and my 4 zone 8 speaker selector switch for my ceiling speakers with a separate not passive but an 8 inch active subwoofer, if it is wired and set up correctly this little amp @ 80RMS 100watts of power into 4 ohms can deliver enough power to shake my whole house at quarter of the volume from watching a movie or playing music it’s very clean sound with no hum feedback, it has a phase control to adjust for sub placement, a crossover control so you can adjust and set the low pass to your desire level and an overall volume control to set the desire volume, it will automatically switch off after 15 minutes if no audio signal is detected so no need for you to switch on and off manually. My recommendation is not to use speakers that are more than 8 inch 4 to 8 ohms as stated in the manual. Following a correct set up this little amp will deliver a clean solid deep bass without being out of phase with your system. This sub amp can also be used for powering an in-wall passive subwoofer like the OSD IWS 8 series which I will be doing later.

## Features

- BRING ON THE BASS: A highly efficiency Class D subwoofer amplifier that serves up big bass with up to 300W max power
- WORKS WITH ALL RECEIVERS: Compatible with older and newer source equipment and includes LFE, line-level and speaker-level inputs for greater flexibility
- ADJUSTABLE CONTROLS: Includes adjustable phase and low pass filter to dial in just the right amount of low frequency sound effects
- EFFICIENT CLASS D TECHNOLOGY: A highly efficient Class D sub amp that is ideal for budget-minded users who want a feature-rich digital sub amp that does not run hot or take up a lot of space
- COMPACT DESIGN: Measures only 3” inches high, 9 ¼” deep and 16 ¼” wide to fit just about anywhere

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07R4464D3 |
| Item model number | SMP-300 |
| Manufacturer | OSD Audio |
| Package Dimensions | 67.06 x 34.04 x 16 cm; 3.63 kg |

## Product Details

- **Brand:** OSD Audio
- **Manufacturer:** OSD Audio
- **Mounting type:** Surface Mount
- **Number of channels:** 1
- **Output power:** 300 Watts

## Images

![SMP300 Class D Digital Subwoofer Amplifier Rated at 300W Max - Image 1](https://m.media-amazon.com/images/I/71lL+-FKfgL.jpg)

## Questions & Answers

**Q: how much power rms at 8 ohms?**
A: The manual mine came with "the 1000 Watt version" -- details it at providing 497 watts RMS at 8 ohms.

**Q: Anyone have an issue with the speaker out port not working?**
A: First off , do you have a audio signal out from the receiver/ amp to the input of subwoofer? Please check wiring diagram of the manual it should work.

**Q: Does the SMP100 require a 12v trigger cable to work properly?**
A: The SMP100 includes auto sensing that turns on the amp when an audio signal is detected then turns off automatically after 15 minutes when a signal is not detected, but it also has the manual on/off switch.

**Q: Will this work with a polk s35 center channel speaker?**
A: Yes. But this amp would be overkill. Simply get an a/v receiver instead.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Review
*by M***N on 22 March 2021*

It's a simple connect and play could not be any more simple. I hooked it up to a 10'' JBL Subwoofer and i am happy.

### ⭐⭐⭐⭐⭐ Review
*by R***L on 14 January 2020*

Received this OSD SMP-100 subwoofer amp on January 9th 2020, after looking at different models this one made the most sense. After hooking it up and doing my tests this amp was exactly what I needed to include in my whole house audio system. This sub amp works excellent wired into my receiver and my 4 zone 8 speaker selector switch for my ceiling speakers with a separate not passive but an 8 inch active subwoofer, if it is wired and set up correctly this little amp @ 80RMS 100watts of power into 4 ohms can deliver enough power to shake my whole house at quarter of the volume from watching a movie or playing music it’s very clean sound with no hum feedback, it has a phase control to adjust for sub placement, a crossover control so you can adjust and set the low pass to your desire level and an overall volume control to set the desire volume, it will automatically switch off after 15 minutes if no audio signal is detected so no need for you to switch on and off manually. My recommendation is not to use speakers that are more than 8 inch 4 to 8 ohms as stated in the manual. Following a correct set up this little amp will deliver a clean solid deep bass without being out of phase with your system. This sub amp can also be used for powering an in-wall passive subwoofer like the OSD IWS 8 series which I will be doing later.

### ⭐⭐ Review
*by A***R on 17 December 2025*

Product came from the USA so it took a little time but after receiving and installing it initially seemed to work OK. However, the trigger function is a problem. Connecting to an Arcam AVR20 Integrated Amp to sync power on/off. The trigger functions fails to operate, indeed there is a "buzzing/fizzing" sound coming from the SMP500 and sounds like a short-circuit... I immediately pulled the power cord fearing damaged to either my AVR20 or the SMP500. I checked the polarity, voltage and current of the trigger cable and AVR20 output and it is within spec ( AVR20 DC +12v 70mA, 3.5mm jack, tip +). and correctly wired. In either the "On" mode or "Music (detection)" mode the operation is as expected. I attempted to find a support link to the manufacturer (OSD) but they only offer dealer support. On the Amazon order page there is no option to "ask a question", so I contacted customer service and the only option was to return the product, no help there. I suspect that it has a fault, or the labeling is incorrect (e.g. the + and - symbols are incorrect or specifications are wrong), can you please confirm the the product labeling is correct (+ and - and trigger in/out and switch setting 12v/On/Music). Setting the switch to "12v" and "External Trigger On" in the software setting is what I understand is correct but that can't be confirmed it seems. I have decided to keep the product but am concerned that it will be a problem in the future, a risk. The reason for only two stars is that there is no UK support, to even ask a question of. So after the 30 days Amazon option of return any warranty is useless it seems.

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*Product available on Desertcart Iceland*
*Store origin: IS*
*Last updated: 2026-01-22*