ivan asked in Consumer ElectronicsHome Theater · 10 months ago

How to determine wattage for custom speakers?

I am considering making some cheap speakers that happened to be all Dayton audio ( because they have good budget speakers) (it wasn’t intentional) and I want to know what amp I should consider getting for those. They have a woofer planar tweeter and a passive radiator. The woofer is 40w rms 80 peak 4ohms, the tweeter is 15 watts rms ( I can’t find the peak power handling on parts express’s website ) 6 ohms. The tweeter will be crossed over at 3000 hertz and the woofer won’t be. The woofer is the Dayton audio tcp115-4 4” and the tweeter is the Dayton audio ptmini-6 planar tweeter and the crossover is the Dayton audio 3k-hps-4. Any help would be appreciated.

3 Answers

  • 10 months ago
    Favorite Answer

    The general principle is that

    the amplifier can be rated for up to 125% of the woofer's power handling capacity

    without much chance of trouble; more if you are careful with the volume control.

    Ignore all "peak" power ratings and use RMS or "continuous" ratings Only.

    Thus, your 40 watt woofers would nominally call for an amplifier rated up to 50 watts RMS (40 X 1.25).

    The lower end should be about 75%, which gives a figure of 30 watts.

    You can use less if it is easier;

    just be careful to not allow the amplifier to clip.

    The crossover will pretty well protect the other drivers.

    (Learning enough about speakers to understand them well takes a long time.)

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  • 10 months ago

    This should have been a reply. But I clicked the wrong button like an idiot.

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  • 10 months ago

    My first thoughts are that a planar tweeter is going to overpower a 4" woofer. While the rated efficiency shows only approximately a 3dB deficit, once you start to crank things up the woofer will quickly fall far behind the tweeter. Planar drivers can keep up when small dynamic drivers fall behind in the output game.

    Dayton is good stuff. Their Classic 10" woofer will keep up to the planar driver far better than that tiny 4" will. It takes a bigger box but it's well worth it. However you will need a midrange to span dht gap between the woofer and tweeter. Perhaps considering using two Dayton Classic 6.5" woofers. Cross over at 3.5 K and you will be good. Forget about amplifier power until you build the speakers. People stress over that far too much.

    • ...Show all comments
    • Get yourself a cheap loudspeaker design program. I use Boxplot. Partsexpress sells at least two different versions. Maybe get a book on speaker design - again, Partsexpress. eBay and Amazon sell them too. I read Ray Alden's books when I was a kid. Right now, you are flying blind.

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