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Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier

Brand:| Model: SPA250
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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.
A restocked/refurbished, or Open Box unit of the product is available -- see it now
  • 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
Part # 
Weight: 13.4 lbs.  
Regular Price$124.80
Sale Price
Dayton Audio Baseball Cap
Qty: 1Part # 520-308
List Price:$19.99
Part # 300-803
Qty:  EA
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Product Details

Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier

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.

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.

• 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
    (120 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.

View similar products to the Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier
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Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier
Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier is rated 4.5583 out of 5 by 120.
Rated 5 out of 5 by from Works w/ Hsu VTF-2 MK2 if you re-drill screw holesThe amp on my Hsu Research VTF-2 MK2 died and I was looking for a replacement. Many people stated in their reviews that this amp is a drop-in replacement. While that is true (the cutout and cables are a direct fit), I found that the screw holes didn't match up.I crudely filled the screw holes with some wood filler, let dry overnight, then re-drilled new screw holes for the new amp. Everything works great with minimal effort.The reason that I filled the old holes with wood filler is that another reviewer stated that he heard a whistling noise from air being forced out of the old holes that went away once he filled them in.
Date published: 2014-10-24
Rated 5 out of 5 by from So far so good for my Onix Rocket ULW 10I purchased this amp about 5 months ago. The amp was a simple drop in and screw installation. Exact fit! It lacks the EQ that was on my original amp and it is rated 50 watts less, but my sub sounds great. Tight, clean, musical and punchy. Just hope the resistors hold up, based on comments of failure.
Date published: 2014-09-05
Rated 5 out of 5 by from Great little amp for the priceGreat amp with great power for a great price. I have no complaints. I use this for 4 shakers and so far it pleases me.
Date published: 2014-09-03
Rated 5 out of 5 by from Very satusfiedPurchased this plate amp to replace a factory Infinty TSS-1200. A little modification and this plate amp sounds better than the original. And quick easy shipping to Canada. Thanks
Date published: 2014-08-26
Rated 5 out of 5 by from Very Surprizing Quality for the PriceAllot of nice features with a quality feel and appearance
Date published: 2014-08-09
Rated 2 out of 5 by from Good value, but has design + build quality issues.These units have some design/build issues which is why a lot of them after 12 months or so. There are 4 resistors which are subject to heat stress and eventually fail, causing random pops and bangs that are heard through the speaker. This can be fixed/avoided by replacing the resistors with higher power and higher quality versions. If it is left too long the circuit boards can become heat damaged and too far gone to repair.The other concern is that QA on these units seems to be low. Upon receiving my unit something was rattling around inside. Living in Australia, sending the unit back was cost prohibitive and I was going to replace the resistors with better ones anyway so i opened it up. A metal washer fell out onto the bench. Upon further investigation, someone on the production line had crossthreaded a bolt holding one of the output transistors to the heatsink as a result the head of the bolt was sheared clean off and the transistor was making very poor contact with the heatsink.Nevertheless, the value of this unit is extremely good if you are capable of rectifying the problems above (and voiding the warranty!) the unit works great!
Date published: 2014-07-27

Product Q&A

Get your questions answered from other customers
who own this product or have experience with it.
If your question requires design or troubleshooting information,
please email  for a prompt reply.
Dayton Audio SPA250 250 Watt Subwoofer Plate Amplifier

I currently own two ULW10 Subs that have already been replaced with the new Amps from Mark back in 2009, but will 250 watts be enough power for this sub and is there anything else coming down the pipe line that will have more power worth waiting for?

Asked by: GRH5
We do not have a cross reference available for this type of thing. Please contact our tech support for more help with this question, or 800-338-0531 x1.
Answered by: MattP
Date published: 2014-09-23

If you want to use just a LFE line in rather that a y cable would it go in the mono left in jack? Also would this be sufficient to power a SVS 20-39CS+ passive sub rated at 300 watts at 4 ohms.

Asked by: Dony45
Yes using the left jack is all you need to use if you only have a single subwoofer output. This will work well with that subwoofer.
Answered by: MattP
Date published: 2014-08-25

Very impressed with the product so far for $155. Could you Recommend an 8" speaker sold by Parts Express that would perform best with this amplifier ?

Asked by: ToneDeaf_Noob
This requires a bit more information in order to proceed. Please contact our tech support for more help with this question, or 800-338-0531 x1.
Answered by: MattP
Date published: 2014-08-01

Two amplifiers to one DVC 4 ohm subwoofer. Could I drive a single subwoofer with two of these amplifiers each powering one voice coil which are 4ohm a piece.

Asked by: Tyty12345
Yes you can use two of these amplifiers one a single DVC subwoofer.
Answered by: MattP
Date published: 2014-08-01

I have a PSB Century Subsonic 2i that appears is no longer working. Would this amp be a proper replacement? I've already measured the opening and will have to make it wider to accommodate, but everything should be okay yes?

Asked by: The Big O
As long as the woofer is 4 ohms this amp will work well as a replacement. I would recommend keeping the bass boost off.
Answered by: MattP
Date published: 2014-07-29

What is the lowest impedance this was made to handle?

Asked by: SPLRaptor
This is designed for loads no lower than 4 ohms.
Answered by: MattP
Date published: 2014-07-21


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