--- product_id: 326278186 title: "SMP300 Class D Subwoofer Amplifier, 500W Max Power, Digital Mono Amp for Passive Subwoofers, Adjustable Crossover, Phase and Volume, LFE Line-in" brand: "osd audio" price: "€ 1184.96" currency: EUR in_stock: true reviews_count: 5 url: https://www.desertcart.gr/products/326278186-smp300-class-d-subwoofer-amplifier-500w-max-power-digital-mono store_origin: GR region: Greece --- # Compact 3" height fits anywhere 500W max power punch Adjustable phase & low pass filter SMP300 Class D Subwoofer Amplifier, 500W Max Power, Digital Mono Amp for Passive Subwoofers, Adjustable Crossover, Phase and Volume, LFE Line-in **Brand:** osd audio **Price:** € 1184.96 **Availability:** ✅ In Stock ## Summary > 🎶 Unleash the bass beast—compact power that makes your sound unforgettable! ## Quick Answers - **What is this?** SMP300 Class D Subwoofer Amplifier, 500W Max Power, Digital Mono Amp for Passive Subwoofers, Adjustable Crossover, Phase and Volume, LFE Line-in by osd audio - **How much does it cost?** € 1184.96 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/326278186-smp300-class-d-subwoofer-amplifier-500w-max-power-digital-mono) ## 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 - • **Efficient & Cool:** Class D digital amp technology ensures high efficiency without overheating or bulky size. - • **Space-Savvy Design:** Slim 3" height and compact footprint fit effortlessly into any home or professional audio setup. - • **Powerful Bass Impact:** Delivers up to 500W max power for deep, room-filling bass that commands attention. - • **Precision Bass Tuning:** Adjustable phase and low pass filter let you customize bass response for perfectly balanced sound. - • **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 sleek, Class D digital subwoofer amplifier delivering up to 500W max power. Designed for both legacy and modern audio systems, it features versatile input options and precise bass tuning controls including adjustable phase and low pass filters. Its compact 3-inch height and efficient design make it ideal for professionals and audiophiles seeking powerful, customizable bass without sacrificing space or energy efficiency. ## 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: Good Enough Amp for 70v Commercial. Review: It works with SONOS Amp ## Features - BRING ON THE BASS: A highly efficiency Class D subwoofer amplifier that serves up big bass with up to 500W 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 | | Brand | OSD Audio | | Customer Reviews | 3.8 out of 5 stars 32 Reviews | | Included Components | Subwoofer Amplifier | | Item Weight | 3.63 kg | | Manufacturer | OSD Audio | | Model Number | SMP-300 | | Mounting Type | Surface Mount | | Mounting type | Surface Mount | | Number of Channels | 1 | | Number of channels | 1 | | Output Power | 500 Watts | | Output power | 500 Watts | | Package Type Name | box | | Package type | box | | Specification Met | CE | | UPC | 810281010946 | ## Product Details - **Brand:** OSD Audio - **Manufacturer:** OSD Audio - **Mounting type:** Surface Mount - **Number of channels:** 1 - **Output power:** 500 Watts ## Images ![SMP300 Class D Subwoofer Amplifier, 500W Max Power, Digital Mono Amp for Passive Subwoofers, Adjustable Crossover, Phase and Volume, LFE Line-in - 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 ### ⭐⭐⭐ Good Enough Amp for 70v Commercial. *by I***N on 21 July 2022* ### ⭐⭐⭐⭐⭐ It works with SONOS Amp *by J***N on 6 June 2025* ### ⭐⭐⭐⭐ Not Sure… *by J***. on 23 February 2024* ## Frequently Bought Together - OSD Audio SMP300 Class D Digital Subwoofer Amplifier Rated at 500W Max - OSD Trimless in Wall Subwoofer Dual 8" Woofers 300W Sealed Enclosure Magnetic Grill SL800 - FosPower Banana Plugs 12 Pairs / 24 pcs, Closed Screw 24K Gold Plated Speaker Plug Connectors for Speaker Wire, Wall Plate, Home Theater, Audio/Video Receiver, Amplifiers and Sound Systems --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.gr/products/326278186-smp300-class-d-subwoofer-amplifier-500w-max-power-digital-mono](https://www.desertcart.gr/products/326278186-smp300-class-d-subwoofer-amplifier-500w-max-power-digital-mono) --- *Product available on Desertcart Greece* *Store origin: GR* *Last updated: 2026-04-24*