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Dayton Audio SPA250 250 Watt Subwoofer Amplifier
Dayton Audio SPA250 250 Watt Subwoofer Amplifier

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Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier

Brand:|Model: SPA250|Part # 300-803
Engineered to provide flexibility, ample power, and reliability, the Dayton Audio SPA250 delivers high fidelity subwoofer amplification and is tailored for home audio and home theater audio systems.
Due In: 5/17/2016
List Price$199.99
Regular Price$139.80
You Save11%
Sale Price
Part # 300-803
  • Switchable 6 dB @ 35 Hz bass boost
  • Mono Class AB output stage for solid, well defined output
  • Low-level and high-level inputs connect to any system
  • Manual, auto, or triggered on/off modes for compatibility with any automated system
  • Variable gain, crossover point and switchable phase controls optimize room integration
  • Switchable 120/240V input voltage
  • Energy efficient—draws less than 1 watt in stand-by mode

Product Details

Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier

Bass boost or flat…you choose and the SPA250 delivers!

The Dayton Audio SPA250 subwoofer amplifier produces 250 watts of clean power output, and combines with a host of flexible user options to make it an unbeatable choice. A user-configurable bass boost circuit creates a 6 dB peak at 35 Hz, which allows sealed subwoofer designs and certain ported enclosures to achieve their optimum bass extension and maximum "flat" output.

Connects to almost any home audio system, and does it with ease

The SPA250 features RCA line level and banana jack speaker level inputs and outputs, automatic power-on that is triggered by any audio input signal, and a phase reverse switch to match the subwoofer to your room and your other speakers. A single amp can accept a stereo input signal and combine it into mono, which is preferred for sub bass reproduction. A preamp or receiver's LFE output may be connected to the SPA250's Left (mono) input. The internal low pass crossover is fully adjustable between 40 and 180 Hz, and of course the amp has built-in protection against internal and external faults.

We haven't run out of great features to talk about

• Variable low-pass filter at 24 dB/octave attenuation from 40 Hz ~ 180 Hz
• Switchable phase 0° (NOR) or 180° (REV)
• Variable gain MIN/MAX input voltage dependent
• Speaker level high-pass outputs 6 dB/octave at approximately 180 Hz @ 4 ohms, 90 Hz @ 8 ohms (i.e. 220 uF electrolytic capacitor)
• Line-level full bandwidth (10 Hz- 20 kHz) outputs/throughputs for adding or "daisy chaining" additional amplifiers
• Subsonic filter 12 dB/octave high-pass filter centered at 20 Hz
• Damping factor at rated power: 114 @ 100 Hz

Specifications: • Measured power output: 156 watts RMS into 8 ohms @ 0.1% THD, 252 watts RMS into 4 ohms @ < 1.0% THD • Signal to noise ratio: 90 dB A-weighted • Input impedance: 10.4K ohms • Bass boost: Switchable, 6 dB @ 35 Hz • Low pass adjustment: 40 Hz to 180 Hz • Phase adjustment: 0º (normal) 180º (reverse) • Power requirements: Switchable, 115/230 VAC, 50/60 Hz • Dimensions: 9-13/16" W x 9-13/16" H x 5" D • Cutout dimensions: 8-1/2" W x 8-1/2" H.

Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier
  • BrandDayton Audio
  • ModelSPA250
  • Part Number300-803
  • UPC844632094897
  • Product CategorySubwoofer Plate Amplifiers
  • Unit of MeasureEA
  • Product Rating
    (168 Reviews)
  • Weight13.4 lbs.
  • California Prop 65

    Warning: California residents only. Please note per Proposition 65 that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

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Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier
Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier is rated 4.4345 out of 5 by 168.
Rated 5 out of 5 by from Another HSU VTF-2 repairedRepaired a HSU VTF-2 with a blown amp. I thought I was having the "loose plug" issue with new amp, but Tech Support told me to push harder to seat the plug into the socket on the amp. That worked, so I am a happy camper right now. For my HSU, the new amp fit the old cut-out very well, but the screw hole locations are slightly different, so minor drilling needed for new holes. I also scraped the old foam gasket out, since the SPA250 had its own foam gasket around the hole.
Date published: 2016-03-11
Rated 5 out of 5 by from Working better than the old 240I just replaced my now defunct Dayton 240 with the new 250, and I'm pleasantly surprised. The bass is tighter than the old 240 (lasted 6 years), and this is the 4th plate amp on the HTD sub, so it is too good to throw away. One change I noticed immediately was eliminating the three prong plug with only a two. I assume the hum issue from using the house ground finally caused a change. If you listened to the video on this site about RCA sub cables, please listen to what they say. I had an old single cable that wouldn't turn on the sub in auto mode. My new German KabelDirekt sub cable has one RCA connector at the amp and two at the sub. As soon as I switched cables, my auto mode works well.
Date published: 2016-03-03
Rated 1 out of 5 by from Dead out of the boxUnit failed instantly upon first turn on. Upon performing a Google search, this is not uncommon for this unit.
Date published: 2016-02-03
Rated 4 out of 5 by from This Amp has some Bass OutputThe parts finish is excellent & everything operates smoothly. The IEC power cable fit tight in the port, other users had problems with it falling out. So that problem must have been taking care of by Dayton Audio. I didn't have a problem with any hum, but I did buy a Ground Loop Isolater for $9.80 (part # 265-012) just incase & I used it anyway to fix audio noise on my PC. I have had no problems with the Auto On feature & works just like its supposed too. The Bass Boost is in a very dumb area & has a very small switch. But this isn't a big deal anyway. The Bass Boost button is really for a sealed box settup to compensate for the dB loss at low frequency that a sealed box settup encounters. Just sett it & forget it for your subwoofer settup, turn it on for a sealed box settup & leave it off for a ported box settup. You can still use the Bass Boost button for a ported box settup if you like, but more than likely it will be to peaky or might over power your subwoofer. Some thing else people have said is that you can't use Banana Plug connectors on the High Level Inputs & Outputs, & that is not true. All you have to do is remove the plug in the center of the Binding Posts & the hole for use with Banana Plugs is right there. Also if you need to remove the spade connectors off the amps speaker wire, so you can connect a subwoofer with binding posts, you can do so without voiding the 1 year warranty. I had this problem when I went to install my subwoofer & it had binding posts instead & called Parts Express about my problem & they told me it was fine to remove the spade connectors if needed. The bass output on the SPA250 Plate Amp is most excellent & doesn't let you down one single bit. I built my own custom subwoofer settup & it ended up being a complete beast. The bass output is just wicked & is comparable to a car audio settup. It hits so hard & low when I listen to Dubstep, Rap, Industrial, & Black Metal music that it will distort your vision! I use it in my small bedroom only for listening to music on my PC & for playing video games on my Xbox 360 & Xbox One consoles. I totally recommend that you save yourself alot of money & build your own powered subwoofer. I use mine everyday for many hours straight & it gets a little warm & nothing more. Plain & simple this SPA250 Plate Amp has alot of bass output & is well worth your money. I totally recommend this amp to anyone who wants an excellent quality replacement or is building a custom made powered subwoofer for them self. I hope it will last me over 10 years of use & I will be most pleased. I would have given this product 5 stars if Parts Express would have given me the bonus item I was supposed to receive with this item, a Dayton Audio - Black Baseball Cap (part # 520-308) , but I'm only going to give it 4 stars because I never got the item.
Date published: 2016-01-15
Rated 4 out of 5 by from Good Value, some drawbacksThis amp works like it should. It is a good match for the 12" Dayton classic sub. I am happy with the combo.The base boost is internal, you need to remove a small plug on the inside of the amp to activate the boost. When installed this plug is inside of the enclosure. So, unless you want to remove and reinstall the amp, the boost is either permanently on, or permanently off.The auto-on feature is finicky. It will not power on at low volume. I made a few adjustments to my old AV receiver and it helped, but not a complete fix. When it powers off I get a noticeable thump.
Date published: 2016-01-09
Rated 5 out of 5 by from still going strong after a yearI bought this last winter to replace an amp in my 15 year old Velodyne 10" sub. Plate dropped right into place with no issue and has been working great ever since. Has more power than the original amp, and bass seems tighter as a result. Auto off occasionally makes a small pop, but auto on/off seems to work great otherwise. It's in a 5.1 system paired to a Mirage LCR soundbar and it blends very well after a bit of tuning and placement testing.We listen to music for several hours per day so it's on quite a bit ... but no quality issues so far. Great product for our use.
Date published: 2015-12-26
  • 2016-05-02T06:17CST
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Product Q&A

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Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier

Using this with 4 50w shakers.. What should be the frequency and gain set at? If it's personal taste . What is yours set at? 

Asked by: Victory82
There are really not going to be a correct answer for the again as it will depend on input signal level, efficiency of the speakers and that sort of thing. What I would do is set the crossover at around 60 Hz and have the gain all of the way down. Then bring up the gain until you can feel the shakers. Once you feel them, just back off a touch so they are really only noticed when they are not on.
Answered by: Chrisf
Date published: 2016-03-24

will this amp be a good replacement and fit correctly into a B&W AS6 subwoofer?

Asked by: emoc_squirter69
Electrically it should work, but I do not have any type of specifications on what B&W used in their speakers. It is generally best to measure the cutout and plate size to see if it will fit physically.
Answered by: Chrisf
Date published: 2016-04-01

I am looking to replace my amp plate on my HSU VTF-3 MK2.  I would like a couple options that would fit perfectly in the space provided. Thanks!

Asked by: TMallegni
For assistance on specific vehicle applications please contact our technical department directly at 800-338-0531 or by email at
Answered by: Chrisf
Date published: 2016-03-07

Will the SPA500 fit in the same spot as you SPA250?  Specifically would the hole size and mounting screw locations be in the same place?

Asked by: jerryh
The SPA500 is larger in all dimensions and will not fit the opening for the SPA250.
Answered by: Chrisf
Date published: 2016-02-24

Can I connect this sub plate amp as follows?: line level input to sub amp from my TV (1/8" mini to RCA) line level output to separate power amp is full range? No filters? leading to main speakers?

Asked by: jackreynolds
Yes, the low level outputs are just a full range pass through so that will work well.
Answered by: Chrisf
Date published: 2016-02-09

I'm looking to buy this to power 2 to 4 Aurasound Bass Shakers, but how do I connect them to the amp? I see the positive and negative wires in the back but they have some kind of connector on them. Can I just cut the connector off and attach speaker wire?

Asked by: MikeLL
That is correct you can just remove the connectors or use a male faston type connector to attach to the black and red output wires on this amplifier.
Answered by: Chrisf
Date published: 2016-01-26
  • 2016-05-02T06:39CST
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