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SMP250 Mono-Channel Class A/B Subwoofer Amplifier with 250 Watts of Power

Product code: OSD-SMP250

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Features & Specifications

If you're looking for a subwoofer amplifier, Outdoor Speaker Depot 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.




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37 Questions & 38 Answers
from Toronto Ontario asked:
March 10, 2019
Does this unit come with rack mount ears. Or can you buy them separately?
1 Answer
HI Kevin: The SMP250 is no longer available check out the Digital SMP500 Dedicated Subwoofer Amplifier with remote control and DSP effects. Plus it is shipped with rack mount ears. And in stock. TL/5447
Submitted by: Tim Leahy on March 19, 2019

from Houston asked:
January 4, 2019
I have this SMP250 amplifier but still need some subwoofers. I'm looking to add 2 8 ohm speakers in parallel. I read all the questions and I'm not too clear, can this handle 4 ohms?
1 Answer
Hi Melinda: Great question, ironically we had been pushing the SMP250 as a 4-ohm Sub Amplifier, but after testing the unit and verification from our factory, this SMP250 will only work with an 8-ohm load. That means it will drive a single 8-ohm sub. Note, the SMP250 is no longer available, scheduled to be replaced by the SMP300 which will do a 4-om load. It will be available the first quarter of 2019. We do have an SMP500 in stock with more power, an DSP circuitry, Remote Control and will handle a 4-ohm load. Note, there is a 30-day performance guarantee if you want to exchange the SMP250. Good luck TL/5353
Submitted by: Tim Leahy on January 6, 2019

from McKinney, TX asked:
August 9, 2018
How can I hook up 2 subs to the SMP250 amp? One sub is an IWS-88 (in-wall) and the other is an SS-8. My receiver is a Sony STR-DH800. Thanks.
2 Answers
Hi Adam: A better choice for your application is the SAM300 which you can find on our OSD Premium site under the Black Series Amplifiers. Unlike the SMP250 which needs to see only an 8-ohm load or higher the SAM300 will drive a 4-ohm load. It turns out the IWS-88 is a 4-ohm subwoofer and would be a better matched with the SAM300 Sub amp. The SAM300 is connected to the single Subwoofer output on SONY SDR-DH800 using a single channel Subwoofer cable and an RCA 1 Female to 2 Male RCA adaptor allowing you to connect to the Right and Left input RCA preamp input. The SS-8 Powered Subwoofer will be linked from the Right and Left RCA Outputs to the Right and Left Inputs on the SS-8 Subwoofer. You will need an RCA patch cord depending on how far apart the sub amp is to the SS-8 Powered Amplifier. If you have a problem running a cable to the second Subwoofer, then we have a Wireless Subwoofer kit as a solution, the WSK100. Lastly, you will need to connect the In-wall subwoofer with our CL3 custom install rated two conductor speaker wire either 14 or even 12 gauge; we stock both available in 50 to 500-foot lengths. You will need to contact the Out Door Speaker Depot Sales Team to place your order for the SAM300 sales team. The SAM300 is not available on-Line, but you can place the complete order with them as well. TL/5152
Submitted by: Tim Leahy on August 9, 2018
HI Adam: Update: The factory has confirmed the SMP250 does not drive a 4-ohm load (8 -ohm only). In theory, you can not drive two 8-ohm subwoofers in parallel. What was your outcome, did you connect the two subs to the SMP250? TL/5152 updated
Submitted by: Customer Service - Q&A on January 4, 2019

James M Smith
from Minnesota asked:
June 26, 2018
I'm running 2 AP650's on my deck powered by an Onkyo TSXR508 - 80W/channel. The base will distort if run too hard so I am going to install a JBL SB210 subwoofer. Will this amp work for the SB210? I think that will handle 800W but I only need it for a 10 x 40 foot deck. Thank you
1 Answer
Hi James: When you say you are using 2 AP650 do you mean one pair of AP650s or two pairs of AP650? The ONKYO TSXR508 has two Zone 2 outputs. One is a preamp output where you need an external amplifier to drive your second zone especially if you are driving two pairs of any speakers. The other is a speaker (or high) level output where you are using the internal channels 6 and 7 (@ 80W per) to drive a single pair of speakers. And based upon an area of 10 x 40 foot I would think you would need two pairs with each speaker about 8 feet apart, set up would be right, left, right then left. One pair would not provide enough coverage so you tend to overdrive the single pair into distortion. If you have 2 pairs of AP650 you might consider adding an external amplifier like our AMP200. And all this to consider before adding a subwoofer like the Bad Ass JBL SB210. No matter what happens with the AP650 or AP650s I think the SMP250 will work but the new SAM500DSP would be a better match to get the most potential out of the JBL. The killer system would be the AP650 powered by the AMP200 and the JBL SB210 connected to the SMP500DSP. Let me know if I can clarify further: TL/5075
Submitted by: Tim Leahy on June 26, 2018

from Sioux Falls, SD asked:
April 19, 2018
Hello, I bought two of the IWS88 subwoofers for one in the front and one in the back of my room and the SMP250 Subwoofer Amp for my 7.2 surround sound system. Can I connect both subwoofers to the one amp or does each subwoofer need it's own amp? Also whats the best way to connect the Amp to my A/V Receiver? I have a Denon AVR-X2300W 7.2 receiver with two subwoofer pre-outs.
1 Answer
Hi Tim: The SMP250 is limited to to an 8 ohm load so would only be able to drive a single IWS88 rated at 8 ohm. You might want to checkout the SAM300 on our OSD Audio Premium site ( which is rated at 300 watts peak and 4 ohm stable so it can drive the 2 IWS88. Not only will it drive your 2 subs but it also has a bass boost circuit that is variable between 25 and 50 Hz where you select a point and you have the ability to add up to 12 dB of gain. There is no price on line so you will have to contact customer service for a special price. Very close to the SMP250 (about 15% higher). But you can have the one sub drive both speakers. If you still want more than you could add a second SAM300 and have a dedicated amp per driver. We are also adding two bigger sub amps a 500 and 100 watt beast. Stay tuned... look for more info in the next week on our site. Regarding your second question on connecting the Sub Amp to the DENON Receiver. You would connect a single sub woofer cable to output #1 to the LFE input on the SAM300. You have two options for connecting the 2 IWS88. You could wire the speaker output from the SAM300 to the first IWS88 then run a wire from the inputs of the IWS88 out to the inputs of the second IWS88 (both the wire from the SAM300 and wire out to the second IWS88 would share the same input connector). Or you can home run both sets of 2 conductor wire back to your component rack and tie the two connectors to the speaker outputs (even use Banana plugs if you want). Note this might be the best especially if you add a second SAM300 to your rack. The LFE (Low Frequency Effects) allows you to control the setting s of the SUB at the Receiver (recommended for home theater). Let us know if you need anything else, TL/4918 There is a 30 day satisfaction guarantee on whatever you buy from us.
Submitted by: Tim Leahy on April 20, 2018

Floyd Lawler
from Anderson, Indiana asked:
January 19, 2018
Hello....I have a cerwin-vega lw-12 powered sub woofer that has a fried amp. The woofer is fine. Can I use this mono amp as a replacement after making the necessary box changes? Thanks
1 Answer
HI Floyd: You would need to check with Cerwin Vega to see if the driver is 8 ohm or 4 ohm. Might even be a Dual Voice Coil. If it is a single 8 ohm driver and you have access to connect the speaker leads from the SMP250 directly to the inputs of the CV 12" driver then it should work. The SMP will only work with 8 ohm or higher. I do not believe you can connect through the high level speaker inputs on the back panel of the Amplifier plate. Good luck TL/4759
Submitted by: Customer Service - Q&A on January 20, 2018

from GA asked:
January 11, 2018
I have the trigger switch set to Music, however, I don't think the amp is powering down when I turn my preamp off. Shouldn't the red power light go out when the unit powers down? Mine stays on all the time.
1 Answer
Hi Dave: I do not believe the red power LED goes off unless you physically turn the Power Button off. The Green signal LED to the right of the red LED should turn off. It typically takes 5 to 15 minutes to go into standby mode. Then when music turns on the Amp comes back to life. The Auto Sensing does not work if the Power Switch is turned off and no red Led. Unfortunately there is no description in the Owners manual how this is supposed to work. TL/4743
Submitted by: Customer Service - Q&A on January 18, 2018

Geoff Marshall
from Chicago, Illinois asked:
December 1, 2017
Planning to setup two in wall subwoofers and wanted to make sure if the SMP250 is 4 ohm or 8 ohm stable
1 Answer
Hi Geoff: The Amplifier is limited to an 8 ohm load. It will not allow you to parallel two 8 ohm subs. Due to many calls we are designing a step up to this Sub Amp that will have much more power and will be rated at 4 ohms so you will be able to connect two 8 ohm subs in parallel. We hope to add this new amplifier in the first Quarter 2018. Stay Tuned TL/4674
Submitted by: Customer Service - Q&A on December 1, 2017

from Lowry, SD asked:
November 10, 2016
We have had this amp installed for less than 2 months and it won't turn on. Any suggestions or has anyone experienced this? Could it be the power switch?
1 Answer
HI Jon: I am sorry to hear you are having issues. Has the unit ever worked or produced sound? Does it light up (Blue is active and Red is in standby on the front panel). If the panel light is red there may be a short and the amplifier might be in protection mode (check your cables) What is the turn on option set to? Trigger/Auto On/Normal; This should be set to Normal which is controlled by Front power switch. Your input for single source should be Line 2 Input (RCA Input low or signal level)? What source are you using? Did you adjust your Master Level Right and Left knobs (with screwdriver) Make sure front volume control is wide open turned all the way clockwise. Did you check the internal fuse located in AC plug outlet on right side of back panel? Still dead, contact our RMA department. Good Luck: TL/4122
Submitted by: Customer Service - Q&A on November 10, 2016

from Florida asked:
December 21, 2015
I need your help to know what product is the correct for me. I have 2 passive subwoofers SONY (from Sony muteki 5.2 model HT-M5 or well SRT-KM5 home theater) in this case the model of my 2 subwoofers are SS-WP7M, they are for 4 Ohms. Recently I purchase a new Sony Receiver 7.2 STR-DN850 model but as this receiver only offer outputs for subwoofers by 2 RCA. I find some info for my subwoofers: Sony reports that they are to support 280 RMS in 4 ohms, 100 Hz with THD 30%, and 175 Rms in 100 Hz with best THD of 10%. -- REALLY I DON'T KNOW if the OSD250 is my right solution to support BOTH subwoofers and offer at least 150 RMS for each one or I need 2 OSD250 amplifiers ?, I appreciate your help and suggestions about to define the right amplifier to convert them from passive to Active Subwoofers. I you have questions please let me know to can give more information...Best Regards.
1 Answer
Hi Cesar: I would recommend purchasing one SMP-250 and connecting the two sub woofers in series since they are both 4 ohm. You would connect the (+) positive output from the SMP-250 to (+) positive input of the first sub woofer. Then connect the (-) negative input of the first sub-woofer to the (+) positive input of the second sub-woofer. Then connect the (-) negative output of the second sub-woofer back to the (-) negative output of the SMP-250. That would be the most affordable solution and the amplifier should see a 8 ohm load. Play that for awhile and see if the output is satisfactory. To get more bass/output you would need to have two SMP-250 amps, one for each speaker. You will get the most output since each 4 ohm speaker will increase the output closer to 250 watts. TL/3628
Submitted by: Customer Service - Q&A on January 20, 2016

from Canada asked:
November 21, 2012
Can this amp run both subwoofers rated at 150W each?
1 Answer
Hi Joe, The bigger concern when trying to match a pair of woofers to a sub amplifier is the Impedance Rating of the subs not the power handling. I am assuming you are using two 8-ohm drivers for home (car audio uses mostly 4 ohm drivers). When you connect both 8-ohm subs in parallel, you will increase the output of the SMP250 so you will have plenty of current to drive both subs. The SMP250 is a High Current Amplifier that will work in a 4-ohm load, which is what the impedance drops to when connecting two eight ohm drivers in parallel. Connect both the Positives to the Positive Output and both of the Negatives to the Negative Output. In Series, connect the Positive from the amplifier to the first Subwoofer's Positive connection then connect the Negative from the First sub to the Positive of the second sub. The Negative from Second Sub is then wired back to the Negative Output from the SMP250 amplifier. This creates a 16-ohm load and drops the output of the amplifier in half. Let us know if this helps. TL/MA - 1398
Submitted by: Customer Service - Q&A on November 23, 2012

from Pittsburgh PA asked:
January 17, 2018
I have the smp250 connected to a Denon avr 4400 receiver and a osd iws88 in wall sub. I just hooked it up and when you first turn it on I get a loud pop noise and then a hum. After that the amp light turns red and never turns back on when the receiver comes on.
1 Answer
Hi Jason: So it sounds like your SMP250 is dead. No lights are on but no sound at all? If so you need to contact our RMA department and see if you can get it exchanged. TL/4756
Submitted by: Customer Service - Q&A on January 18, 2018

H. David Medlin
from GA asked:
December 24, 2017
Bought this amp on 7/12/2017 and it has been working fine. Watching action movie tonight and noticed that I wasn't hearing any bass response during explosions, etc. Tested with Level tone from pre-amp and the power is way off. I had to turn up both the rear level control and front volume to max to get hardly anything out of it. Previously I had the rear level at about a quarter and set the front volume between quarter and half. Also noticed no heat from the amp, used to be a bit warm when placing hand right above vents on top of unit. Obviously something is malfunctioning in the unit. How do I obtain warranty repair or replacement? Thank you. Dave
1 Answer
HI Dave: Please contact our Customer Service Department at 562-687-2600. Good luck TL/4711
Submitted by: Customer Service - Q&A on December 24, 2017

from Miami, FL asked:
August 2, 2017
I have installed the IWS10 woofer in my wall, powered by the SMP250. Every time I play a movie with a lot of bass or lows, I get a crackling sound , like a feed back from the woofer. At low volumes its fine, its just when I turn it up loud that I get this to happen. Any help will be appreciated.
1 Answer
Hi Jessy: If you are connected to the LFE (Low Frequency Effects) output from your Receiver then your gain control on the front panel needs to be set to middle (12:00 o'clock). If your volume level is controlled by the Receiver for the sub as well then you need to turn the gain down as well. It sounds like its clipping. If the driver was blown it would be scratching at any volume. We will try and duplicate the problem. TL/4502
Submitted by: Customer Service - Q&A on August 4, 2017

from Georgia asked:
July 11, 2017
Would this amp be stable to run two 4 ohm speakers in parallel? Wouldn't that be a 2 ohm load? Thanks.
1 Answer
Hi Dave: The SMP250 will connect two 8 ohm subs so it sees a 4 ohm load. Two 4 ohm subs will be too much (2 ohm load as you noted). Wiring them series will work but you will not get the output you are looking for from the two subs. Now ohm woofers and connected them in Series Parallel you would have a 4 ohm load and lots of sub. TL/4466
Submitted by: Customer Service - Q&A on July 20, 2017

from Flagstaff, az asked:
July 4, 2017
Are there rack mount ears available. There are obviously threads for such, but they are not included.
1 Answer
Hi Goran: We do not currently stock rack mount ears. But they are available from our factory and will order a small quantity to have on hand. Check back with us in about 30 days. TL/4449
Submitted by: Customer Service - Q&A on July 13, 2017

from mn asked:
April 9, 2017
does this sense inactivity and turn off on its own ?
1 Answer
HI Tim: Yes this amplifier can be set to Music or auto sensing making sure that the manual on off switch on the front is pushed on. Then as long as the amp sees a signal it will play.. If the source or signal is turned off the amp will go into stand by mode until it sees another signal. It usually takes 5 minutes for there to be no signal before going into stand by mode. Note, the three way switch is labeled Trigger. Music is the Auto signal sensing, Manual switch on the front needs to be on. When the trigger switch is set to On than the front manual switch turns the signal on or off, it has to be done manually. Then in the 12V setting the manual switch needs to be on as well but now the 12 V trigger will send a signal to turn on or off, again the manual switch must be left in the on position. TL/4299
Submitted by: Customer Service - Q&A on April 12, 2017

from NM asked:
March 8, 2017
Hi, On occasion, the subwoofer goes out. If I turn the amp off and back on, it comes back fine. Any idea what can can cause it to stop operating? Impedence mis match? One clue, when the sub stops operating, the direct line out on the RCA outputs operates fine. The sub I'm using is the NILES GSS10 inground sub. Thanks!
1 Answer
Hi Billy: When the amplifier goes out have you touched the chassis to see if it hot to the touch. Sometimes there is an issue with impedance matching where the impedance drops and the current demand goes up which is accompanied by heat the extra current produces. The circuit board heats up and trips the Thermister (heat sensor) which puts the amp in stand by mode until the heat dissipates so the amp is back to safe operating mode. The RCA is a direct pass through from the RCA inputs, they do not go through the Power Supply or amplifier since they are an already amplified signal. Also what is your level setting on the back, the adjustment knob between the trigger switch and LFE input. Try backing that knob counterclockwise down (adjust it with your Volume Knob located on the front panel at full output). You use a Phillips head screw driver to adjust. Make sure your source is at a level where the sound is starting to clip and distort.(no higher than you would normally listen to it). Now turn the level control down where it is no longer clipping. So now you control the SMP250 with the Volume level on the front. Note if you are using the LFE input then your front volume level should be left at half way. The Volume will be controlled by the source bypassing the Volume, Crossover Filter and Phase switch all together . TL/4243
Submitted by: Customer Service - Q&A on March 31, 2017

from purcellville, va asked:
October 14, 2016
Hello, how would I wire this to the Polk Audio Atrium Sub1- ( which has dual voice coils at 8 ohms? Thanks!
1 Answer
Hi Paul: Correct me if I am wrong I am thinking the Atrium Sub Woofer has an internal crossover built in. And you might want to look at our AMP200 instead of the SMP250. The AMP200 would provide a stereo signal to connect to your dual voice coils where as the SMP250 is a Mono amplifier. You need a right and left signal to the sub. The Sub has a Low Pass Crossover that will blockout all high frequencies. TL/4093
Submitted by: Customer Service - Q&A on October 14, 2016

from Minnesota asked:
October 10, 2016
Since this amp does not have an auto off feature, do you have to manually turn it off after every use? Asked another way, will it harm the amp to be left on all the time so it is ready to go whenever the system is turned on? Thanks.
1 Answer
Hi James: Good question, and I have a better answer. There are actually three turn on/off options. First is manually turning on the power switch on the front for all three options. On the back of the amp you have switch labeled Trigger and three positions for the switch, the left is labeled Music; this is an auto sensing choice. When you turn the music off after a 5 to 15 minute delay the amplifier will go into standby. Once you turn the music back on the amp will sense the signal and turn back on. In the second or middle position (On) that is on when all the time unless you push the on/off button in for on and out for off. The third option is a 12 volt trigger that you might connect to another component either Receiver or amplifier. Our Amp 200/300 have a 12 volt trigger in and out that would be hardwired with an aux cable Male 3.5mm to 3.5mm Male. I hope that helps. TL/4089
Submitted by: Customer Service - Q&A on October 14, 2016

from Georiga asked:
October 10, 2016
I have a Yamaha 681 receiver. It has two sub outputs. I have also purchased this amp with two iws10 I am seeking the best hook up method for going from the receiver to the amp to the speakers. If you can please include as much detail regarding wires/adapters and settings as possible... Thank you for your time and input.
1 Answer
Hi Justin: The SMP250 connects to the Yamaha 681 AVR to the Subwoofer Output Jack #1. I believe the connection is a 3.5mm RCA (like your Headphone jack of your phone). It does not specify. But there are 3.5mm adapter cables to RCA to plug into the right and left input of the SMP250. Then you connect the two IWS10 in Parallel to the Red and Black Mono output of the SMP250. You can either run both 2 conductor cables back from the respective IWS10 to the output connecting both positive to the red positive Binding post then the two negative conductors to the black output connector of the SMP250. Or you can run one 2 conductor from the output of the SMP250 to one of the IWS10 sub woofer speaker then run a second 2 conductor cable from the input connection of the first IWS10. I would run the biggest wire available (we have a CL3 FT4 12 Gauge two conductor or 14 gauge). It is also a good idea to create a back box behind the IWS10. At least fill the cavity with Fiber fill if nothing else. You will only need the single sub woofer pre amp out from the Yamaha. TL/4087
Submitted by: Customer Service - Q&A on October 14, 2016

Noe Bodie
from USA, USA asked:
June 30, 2016
Does this have a subsonic or HPF? what is the frequency response?
1 Answer
Hi Noe: This Sub Amplifier does not feature either a Subsonic or High Pass Filter. It does feature a variable Low Pass Filter from 180Hz down to 35Hz. Frequency Response would be 20Hz to 180Hz. I believe the signal level outputs as well as the High Level outputs are full range with no Crossover High or Low pass effect. The Amplifier does feature a LFE (Low Frequency Effects input) for connecting to a Audio Video Receiver that features a dedicated sub-woofer output. When using the LFE input the crossover and phase switch are by-passed. TL/3963
Submitted by: Customer Service - Q&A on July 5, 2016

Rich Hougey
from Concord, CA asked:
June 18, 2016
My backyard system consists of 6 JBL Control Contractor Series speakers and 2 OSD in-ground speakers. I want more bottom end. I am planning to build my own weatherproof sealed sub enclosure to be mounted in an area that is already protected from the weather by the structure of the house. Because I am familiar with the product, I was thinking of using one or two Kicker Solo Baric L7's or similar (4 ohm). My wife does not let me run this system at high volumes, it is normally used for background music. I am wondering if this amp has enough power to drive a sub of this type. I notice the specs do not give power ratings for 4 or 8 ohm respectively. what are the peak and continuous outputs for 4 ohm loads?
1 Answer
HI Rich: This SMP250 is rated at 250 watts RMS at 8 ohm and maybe 250 watts at 4 ohm. The Kicker Solo Baric woofers are either dual 2 ohm or dual 4 ohm. The 8" is 300 W, 10 is 500 W, 12 is 750 watts and 15 will hit 1000 W. In order to get a 4 Ohm load you would need to Series a dual 2 ohm driver. While using a Dual 4 ohm parallel would create a 2 ohm load and wired in series would equal 8 ohm. You would need to be 4 ohm to get the most out of the amplifier but not sure if it would be stable especially since the 8 inch speaker is 84 db (sensitivity) meaning it would not be very efficient needing even more power to get it going. Ironically we are developing a more powerful Sub amplifier with digital processing, IR remote and USB to RS232. But for now we do not have an amp for your application (or at least one that will work with a Car Audio Sub like the Kicker Solo Barics). Sorry about that TL/39040
Submitted by: Customer Service - Q&A on June 21, 2016

from ' asked:
April 17, 2016
1 Answer
dfgdfg One of the many products of repeatedly smashing the keys of a computer in boredom/frustration/stupidity. The cyber equivalent of a chipmunk screaming in anger. So that has been established, now how can I help you? TL/3818
Submitted by: Customer Service - Q&A on April 18, 2016

from New York asked:
March 23, 2016
Would this work with Niles GSS10 subwoofer?
1 Answer
Hi John: This Amplifier would work just fine. The Sub woofer is rated at 50 to 500 watts but the real key is it's sensitivity which is 110dB which means it is really very efficient and does not need a lot of current to make them pound. Good choice TL/3777
Submitted by: Customer Service - Q&A on March 24, 2016

from California asked:
January 22, 2016
Hi, i just bought a smp250 and i connect to a polk audio atrium sub10, the sound is bad, the low pass filter doesnt work... its something wrong whith the amp? i connected at 16 ohms because the atrium has 2, 8 ohms voice coils..
1 Answer
Hi Chad, You would need to wire the woofer in parallel, so it runs at 4 ohm. 16 ohm would not be getting enough output from the SMP250. CS 3669
Submitted by: Customer Service - Q&A on January 22, 2016

from San Ramon, CA asked:
January 20, 2016
I have a bad amp panel on my Infiniti TSS-1200 system so the subwoofer now needs a new amp and wanted to know would this amp work well for JUST the subwoofer via LFE input? I will not be using this amp for anything else but the subwoofer. Subwoofer specs: Subwoofer Low-Frequency Driver: 12" MMD Subwoofer Amplifier Power Output: 250 watts RMS, 500 watts peak Subwoofer: 29Hz – 150Hz (+/–3dB) Subwoofer Crossover Frequency: 50Hz - 150Hz, 24dB/octave, continuously variable
1 Answer
Hi Carl: At first glance the question would be yes. But the concern is that you mentioned a bad amp panel. I am assuming the actual sub woofer for the system is powered by its own internal amplifier. So are you removing the amp panel form the back of the sub and looking to connect directly to the sub from the SMP250? Then connect the LFE from the AVR Receiver that you are using currently. If that is the case it should work... TL/3667
Submitted by: Customer Service - Q&A on January 22, 2016

rod rodrigues
from Oakland, CA asked:
December 18, 2015
I have a SMP250 amp connected to two passive subwoofers, which work great. I am curious is it possible to connect the 12v trigger to my Sony STR-1050 receiver so that when I turn my receiver on, the amp comes on.
1 Answer
Hi Rod: I do not believe the Sony has a 12 volt turn on trigger. It does feature a IR in.out but not sure if that would work with our SMP-250. Sorry about that TL/3626
Submitted by: Customer Service - Q&A on January 20, 2016

from Roseville, CA asked:
January 30, 2015
I am thinking about setting up a in-wall sub and looking at the diagram of one of the subs on your site it shows you connect the red to red, black to black from sub to amplifier output. So my first question is would it matter if the right output was used or does it have to go in the left on the SMP250? Also on the diagram it shows that a single RCA cable goes from the left input to the receiver Sub Out. So my second question is on the SMP250 do I get a double RCA cable to single i.e. red and white RCA male plug it in the left input (Amp) and the other side which is single and plug that into the Sub Out (Rec) or can I get a single RCA to RCA and go from LFE in (Amp) to Sub Out (Rec) Thanks
1 Answer
Hi Bally: The actual output from the SMP250 is a single Red (+) and Left (-). The speaker level connections on the left hand side of the back of the amplifier are for inputs and through outputs to the satellites (which does not apply on your setup). Regarding question #2, I am assuming you are using the In-Wall Subwoofer for your Custom Home Theater application so your first choice is to connect the LFE subwoofer output to the LFE input of the SMP250 Sub Amp. That would be with a 3.5mm to 3.5mm aux cable (which is a smaller connector than standard RCA, eg. Head pone jack on your smartphone). If your Receiver only has a right and left Standard RCA output then connect them to the corresponding right and left RCA inputs on the SMP250. I hope that helps, good luck TL/3118
Submitted by: Customer Service - Q&A on February 2, 2015

from CT asked:
April 19, 2014
Does this unit come with tabs for rack mounting?
1 Answer
Hi Eric, The original model didn't have rack mounts, but the unit has gone through a redesign. We haven't received the new models yet but they may or may not have rack mounts. We just don't know yet. If I have to make a guess, I'd say they probably won't come with rack mounts, as the only amps we sell that do include rack mounts are the commercial amps (i.e. pa90, pa150, pa270). BM 2624
Submitted by: Customer Service - Q&A on April 21, 2014

David Duffy
from Canada asked:
March 23, 2014
Do you know if the amp has a subsonic filter to protect vented woofer systems below tuning frequency? Not the low pass on the front, but a high pass at say 17-20 hz? Thanks. Dave
1 Answer
Hi Dave, The SMP250 does not have a subsonic filter. CS 2559
Submitted by: Customer Service - Q&A on March 24, 2014

from Maryville, Tn asked:
January 1, 2014
I own an NHT W1, mono sub. It is a single enclosure that houses two 12” drivers juxtaposed with each facing outward. It only has one set of speaker inputs on the back of it. I’m replacing the A1 NHT amplifier I purchased with it. Will the SMP250 power this sub unit?
1 Answer
Hi Scott, I can't seem to pull up any specs on that subwoofer. Do you know what ohm load it has? 4ohm maybe? How much power can it handle? Do you know how many watts your NHT amplifier was outputting? Thanks. -BM 2416
Submitted by: Customer Service - Q&A on March 10, 2014

from NY, NY asked:
November 15, 2013
I have had this amp for a little over a year and it is very stable and gives me exactly what i need. I enclosed both my subs between my studs with 1/2 inch MDF enclosures and my bass is terrific. My only issue with this amplifier is that there is no way to power it off remotely. Is there a way that i am able to hook up some sort of RF sensor so i can shut it off with my harmony remote?
1 Answer
Hi Mike, This amp does have the auto on/off feature, which will cause it to turn on and shut off according to the source that is running to it. For example, if you have a receiver running to the SMP250 as the music source, any time you shut off the receiver, the amp will shut off too, and the same goes for when you turn the receiver on. Thus, if your source has remote capability, you wouldn't need a remote for the amp itself, as it will follow the lead of the source. So it doesn't have IR or RF built in, but the auto sensing feature will basically replace that. Thanks! -BM 2334
Submitted by: Customer Service - Q&A on November 19, 2013

Roger Eldridge
from Murfreesboro,TN asked:
July 26, 2013
I would like to power (2) Polk Audio #AM3386-A Atrium sub 10 outdoor passive subwoofers. The SMP250 subwoofer amplifier will be connected to an existing Denon 7.1 home theater receiver. Do you see any issues with this combination?
1 Answer
Hi Roger: You may have a problem going with a mono sub amplifier with the Atrium Sub woofers which features a dual voice coil connection (Right and left stereo input). I would recommend the AMP 200 instead since the output signal from you Denon 7.1 is a dedicated low pass frequency plus the Atrium Subs have built in crossovers as well. You will need to use a Y adaptor (female in to 2 Male) like our OSD; terminating a single sub woofer cable from the Denon7.1 to create right and left input to the AMP 200. You can then hook up one of the Atrium 10 to the Speaker A output and the second Atrium10 to the Speaker B. Your Amp should drop to a 4 ohm load and create plenty of output for your two subs. TL -2106
Submitted by: Customer Service - Q&A on August 21, 2013

from Utah asked:
April 19, 2013
What is the output rating for this amp with a 4 ohm load? I assume the 180/250 is at 8 ohms. I have a 15" sub who's plate amp is dying on that is rated at 350 watts (AV123 MFW-15 amp issue). I just hope this amp will drive it nominally.
1 Answer
Hi Micah, The SMP250 subwoofer amplifier is 300 watts into 4 ohms. The SMP250 will your 15" subwoofer. CL/MA 1811
Submitted by: Customer Service - Q&A on April 23, 2013

from toronto asked:
January 29, 2013
I have 2 10" cerwin vega subwoofers in a box that I used in my car years ago. Can I use this amp and hook those subwoofers up to use for an inhome subwoofer setup? If so what would I have to do? Thanks, Steve
1 Answer
Hi Steve, First you need to determine if these subwoofers are 8, 4 or even 2-ohm impedance. Check to see if they are labeled on the drivers themselves. If you have a model number you can go to the Cerwin Vega web site to look them up. If they are 8 ohm,you can wire them in parallel. If they are 4-ohm you need to go in series (same with 2 ohm.) For parallel, you wire the two positives of the drivers together and terminate to positive output of SMP250. Connect the negatives to negative output of the SMP250. The amplifier will see a 4-ohm load and should have plenty of output and run a little hot. If they are 4 ohm (most likely) or 2 ohm, you will need to connect in series which means connecting the positive output of the SMP250 to the positive input of driver #1 then connect a wire from the negative of the speaker #1 and connect to the positive of speaker #2. Final connection would be between the Negative of Speaker #2 to the Negative output from the SMP250 amplifier. If you can not determine the true impedance of the drivers, go with in series to be on the safe side. TL/MA - 1592
Submitted by: Customer Service - Q&A on January 30, 2013

from chicago asked:
December 23, 2012
I have a IWS-88 connected to the SMP-250. I have the SMP-250 connected to a Pioneer Elite SC-65 receiver. I'm getting very faint sound coming from the sub (and only at max volume setting). I have speaker wires from IWS-88 sub connected to SMP-250 "subwoofer speaker output" port. I have one end of the mono cable connected to the SMP-250 "LFE IN" port and other end connected to SC-65 "subwoofer out" port. Do I need to set the phase correctly? How about the Low Pass Filter? Can you help?
1 Answer
Hi Nimish, Regarding the SMP250, here are a couple of things to consider. You have the Pioneer Elite Audio Video Receiver connected to the LFE input of the SMP250. Make sure your LFE setting on the Pioneer is set to 0 db (the highest setting). Then on the front of the SMP250 set the controls as follows: Polarity to zero all way to the left, the crossover setting should be at 12:00 o'clock (the LFE overrides the high-cut filter) and the Volume Control at 12:00 as well. On the back panel of the SMP250 there is a level (gain) control right next to the LFE input. You want to turn this adjustment at least half way or more depending how much output you want. If you have not touched this, you will notice a huge difference as you turn it clockwise. Once you have set it to acceptable levels, the volume level will be directly affected by the volume levels of the Pioneer. It will increase or decrease along with the other 5, 7 or 9 channels when you adjust the master volume levels. We hope this helps! TL/MA - 1487
Submitted by: Customer Service - Q&A on December 24, 2012

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