I am experimenting with in-wall speakers in a new (sort of small) house. There are a couple of in-wall passive subwoofers that I need to drive with a power amp (since home theater receivers don’t include anything other than line-level subwoofer outputs, as far as I know). I might watch a movie once a week and therefore I don’t want to spend too much money and don’t want the IT closet heated up too much if the amp is left on. I’m wondering if a Class D amplifier if the solution. Here are some ridiculously cheap examples:
What’s wrong with this idea, if anything? Has anyone tried using one of these amps to drive a 10″ in-wall subwoofer or similar? I’m assuming that the power output numbers are completely fraudulent but I figure that even if I divide by four it will be enough power.
Here is an amp marketed specially for your application:
http://www.htd.com/Products/subwoofer-amplifiers/SDA-100-digital-amplifier
I have no idea if it is better/worse than the amps that you mention.
When you wrote “ridiculously cheap”, I thought you must be referring to something like this:
http://www.banggood.com/STA508-2-x-100W-4-Ohm-Class-D-Audio-Amplifier-Board-Stereo-T-Amp-p-912953.html
or maybe even this:
http://www.banggood.com/2-x-15W-4-Ohm-TA2024-Class-D-Audio-Amplifier-Board-Stereo-Mini-T-Amp-p-912952.html
though with those particular amplifiers, you do have to provide your own DC power supply.
(These things are built around class D amplifiers on a chip, and the chip basically defines the performance of the device. They tell you what the chip is, and you can google its datasheet to get its specifications. So despite these being no-name devices which, on that site at least, are described in Chinglish, their real numbers are available with more detail and accuracy than those of anything you might buy in a store.)
Really, any integrated unit (like an old 2 channel receiver) or standalone amp should be easily able to drive the woofers. They are not overly large. The 2 you have listed will be overkill for your needs; but in the future, if you wanted to, you could re-purpose them for some other use. Note that the Behringer apparently has a noisy fan on it, according to reviews.
Nothing wrong with the idea. Runs cooler, distortion is not a big problem nowadays and for movie sub woofer application it’s not going to matter anyway. Those hoopties with subs in the trunk and you Sienna minivans too, run on Ds.
Amps like this http://www.parts-express.com/dayton-audio-sa230-230w-subwoofer-amplifier–300-813 have auto on features so they’re not on all the time. Also has phase and crossover features. Some of those pro amps have fans that run all the time, which are annoying. It’s up to you, but 1000w is overkill for a ten in a small room.
Thanks, Scott. Fans that are occasionally noisy will be okay because everything is in a closet (but at the same time a Class AB amp like the Dayton you reference is not ideal due to waste heat). Also the reader comments seem to indicate that the auto on/off feature does not work well.