- OSD Audio SMP300 Class D Subwoofer Amplifier, 500W Max Power, Digital Mono Amp for Passive Subwoofers, Adjustable Crossover, Phase and Volume, LFE Line-in

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.

So good! Had to set the auto-off to 30 minutes. Frustrating when it turned off every 5 minutes…

Bought this to install in a Friends Bar / Lounge. This was my First time dealing with 70V System, I have to say its pretty Dang Good for Hanging Subwoofers Amp. Only wish it had more power for the price.

Didn't need a lot of power as I'm using with TV 5.1 sound system, as far as that goes works great. The amp detects when signal is coming in and LED goes from RED to GREEN and passive bass comes alive. I realized from photo and manufacturers website that speaker wire connection was thru a terminal block but it's really cheesy and loose as it's a plugin module(only part that doesn't feel quality at all), add to that how tight the 2 terminals are together and it's begging for a loose wire short. The screw down clamps do need seem to be able to hold the wire very tightly either. Why not use banana jacks like the 200W version as there seems to be plenty of room inside(I doubt the trigger input sees much use). May mod that at some point myself.

I tested this amp out separately from its target installation which is my home Flight Simulator. I used some Low Frequency Effect (LFE) sound mp3 example files with a Buttkicker LFE transducer. It appeared to work adequately. I did expect a bit more of a response from the Buttkicker LFE transducer though than I felt. So far, I had no complaints. It is when I installed it together with my Flight Simulator is when things went crazy. These amplifiers are designed to sleep and not enable their final power out amps until they receive a trigger or sense some audio input. As soon as I powered up the amplifier (initially it comes up in sleep mode) my Flight Simulator control electronics went crazy exhibiting very high level noise. Whether the amplifier was in sleep mode or its final amplifier stages energized and enabled, the inputs to my Fight Simulator software from my simulator hardware was exhibiting extreme noise and instability. One set of my simulator hardware actually failed completely upon powering up this amp. I was able to recalibrated thank God and it worked fine without this amplifier being powered up. Since I determined this amp would not be usable with my Flight Simulator electronics, I requested an Amazon return. I returned the amp and purchased the 'Dayton Audio SA1000 Subwoofer Amplifier' from Amazon. Hook this new amp up and everything worked satisfactory with absolutely no electronic noise coming from my Flight Simulator control electronics hardware. All my Flight Simulator control electronics remained quiet and stable. My conclusion is that either I had a defective amp, its design is poor, or being a class D amp, it naturally exhibits electronic noise. In any case I felt obligated to describe my experience with this amp in case any potential buyers might be planning to use it with their game consoles or systems.

I have this running a 6.5 sub and it is doing great. Its got plenty to power my speaker and sound quality seems good. Auto on/off works like its meant to. I don't really like the red light that stays on on standby but that's not a big deal. It is very small and locates easily but gets the job done as well as a big amp.

I'm running 2 passive 7in subs with this single amp and it perfect, my Receiver does not have a power output in the rear so auto shutoff was an important feature i was looking for. so far this little guy has worked splendidly.

Very pleased. Its works well with my SONOS Amp and it drives my outdoor subwoofer. Great bass in the pool courtyard.

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.

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 the "On" mode, it works as expected but the "Music" mode should turn off when a signal is not present and on when a signal is detected, but it's unreliable, sometimes it does, others it doesn't. 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. Update. Now there's a pulsing noise emitting from the driver, even when the phono isn't connected. This noise is sufficiently load that I can hear it 15 feet away in the primary listening position during the quiet gaps in films/music. For a £600+ device this is unacceptable. Now being returned and reduced to one star, zero if there was an option.

Ha ha, not sure if The previous reviewer 'Jack' hooked up wrong or just had a plain lemon, but I've owned this unit for 2 years now in many system scenarios (including an Onkyo THX amp) and it performs beautifully. Sounds solid with an 8ohm load @ 150 watts rms with a lot of head room, shakes the crap out of a 4ohm sub (250 watts rms) but clips out quicker on the volume knob. Crossover potentiometer worked perfectly and protective circuitry reads the power handling feedback of chosen sub superbly never allowing damage to voice coil. Never used longer than a couple hours but heat has never been an issue. Planning to use to power two future in wall subs (in enclosure) with new house build. No subsonic filter but your AV receiver shouldn't be sending those on anyway. Any questions, feel free to ask Simon

el amplificador no es ta pontente como dice, ademas le falta el bass boost y los db del bass boost

Awesome Amplifier. Got real good low tone now!