Dayton Audio SPA100-D Subwoofer Amp Review

[amirm]

This is a review and measurements of the Dayton Audio SPA100-D class D plate subwoofer amplifier. It is on kind loan from a member and costs US $110.

This is a ton of functionality for such a low price. Alas, I miss having balanced input as long RCA runs are a recipe for ground loops to an active speaker.

Dayton Audio Subwoofer Amp Measurements
I started with my 40 Hz tone into 4 ohm load:

We have copious amount of distortion as we saw in its more powerful brother, the SPA300-D. Having learned my lesson from testing that unit, I switched on Bass Boost which should have minor impact. Yet, we see a sharp improvement in distortion level:

Needless to say, this should not happen. As someone suggested in the other review, the filter may have been placed in the feedback loop somehow.

Regardless, seeing how Bass Boost makes the already less than good frequency response even worse, and the fact that the filter acts the opposite way with 2 ohm load, this unit is just as broken as its louder brother. So I stopped testing.

Conclusions
Someone was hoping that the Bass Boost effect was a defect in the review SPA-300D sample. Seeing how this version suffers from the same, we can rule that out and with it, dismiss the SPA100-D as well.

I can't recommend the Dayton Audio SPA100-D.
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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[JSmith]

I can't recommend the Dayton Audio SPA100-D.

I can see why... thanks for the recent plate amps tests nonetheless.

Pics;

JSmith

 

[amirm]

They shouldn't zip tie the AC mains wiring to the low voltage/signal ones. And I hope that black goop doesn't carbonize over time and become conductive!

Still, so much stuff in a device sold for $110 with a 5 year warranty no less!

 

[Videoteque73]

Is there a normal functioning subwoofer plate amp somewhere?

 

[totti1965]

Stop sending such crap to @amirm!

 

[amirm]

I have one more to test.... It is discontinued though....

 

[JSmith]

Stop sending such crap to @amirm!

Yeah but the point of sending it in is to find out if it's crap or not.


JSmith

 

[Sokel]

Is there a normal functioning subwoofer plate amp somewhere?

Demand is probably low, even miniDSP never bothered to update theirs, they are still using icepower modules from 2 generations ago, despite the price.

 

[pma]

As long as we speak about those cheap products used in mediocre systems, there is no reason for the manufacturers to make a SOTA parameters product at such low price (case etc.). I would stick with something like ICEpower modules, as suggested by @Sokel . They are good enough for subwoofers. TPA3255 modules with appropriate heat management are good enough as well.

 

[pma]

Audioholics Subwoofer Measurement Standard Part I

When it comes time to size up a subwoofer's performance, the proof is in the measurement! Audioholics takes a hard look at the science of subwoofer measurements in a two-part series covering a broad

www.audioholics.com

 

[AaronJ]

Is it possible that the improved performance of bass boost is by design to give the user an even greater sense of a net benefit from engaging it? Honestly, who wouldn't use it?

 

[Guerilla]

Is there a normal functioning subwoofer plate amp somewhere?

For sure from some of the OEMs for PA industry. Their names slip my mind. Also plenty of boards you can mount on a piece of sheet metal.

 

[markk]

IMHO this is a much worse amp than the 300. The higher order distortion is really quite poor. While the 300 might pass in a lower fidelity garage/kids playroom/bathroom? (never thought about a sub in a bathroom...see the other thread...), this unit will have painfully obvious higher order distortion.

Hard pass

 

[markk]

Stop sending such crap to @amirm!

To be fair, how do you know until you test it. Occasionally you find budget gold. Just not today...

 

[Steve Dallas]

Too bad I can't live without one of my SVS subs for a few months to send its amp to Amir. It would be interesting to see how SVS plate amps measure.

If this lack of performance persists, it seems to make sense to use passive subs driven by monoblocks or a PA amp or something, assuming space allows.

 

[amirm]

Is it possible that the improved performance of bass boost is by design to give the user an even greater sense of a net benefit from engaging it?

No. If you turn it on, it will become even more of a one-note sub as it boosts the already there peak.

Second, performance actually dropped with 2 ohm load with bass boost engaged in the review of the 300! There is some kind of load dependency in the way they have implemented it.

 

[Power Pop 23]

Thank you Amir and @Grenadine for measuring three subwoofer plate amplifiers.

Their measured performance makes me wonder how well plate amps in lower-priced subwoofers would measure.

 

[amirm]

I have long thought about testing them, especially in the context of noise and harmonic distortion they produce. But logistics are hard.

 

[dtaylo1066]

I think I saw this one today when I took my dog for a walk. I was thinking of making a sub and using a Dayton plate amp. Ugh. The are poop!

How does the Dayton 1200 finished sub get such good reviews as it must be using a similar amp?

 

[DearSX]

"Holy moly, Batman! That's horrible distortion" groaned Robin

Batman stared at the abysmal 30 dB floor in grim silence. In that moment, he pined for his tube monoblocks—amps that, despite their deliberate glass-bottle warmth sitting around 60 dB, suddenly felt like pristine laboratory instruments by comparison.