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LED Acrylic Woofer Box

  1. Jun 17, 2011 #1
    So I built this really nice woofer box for my 6.5inch sub. All clear acrylic, and working on sealing and reinforcing the sides and back.
    My question is this:
    Given that I purchased a Dayton Audio 25W plate style woofer amplifier, is there any way I can hook this up so that I can plug a string of parallel connected LED's into it?
    My plan is to shine the LED's in multiple directions (UV) from the backside of the speaker so they aren't shining in anyone's face, pointed at the sides of the box, with UV acrylic paint on the sides and back for a really sweet effect.
    My ultimate goal is to make it so the LED's bump to the music, and if I could get a dimmer and it would be an easy setup, I would do this. However, going through several years of EE has taught me that nothing ever works as planned, so I'm prepared to get a phone charger and plug it into the power receptacle on the backside of the amp for constant LED power.

    I'll go take pics and get model information so you guys aren't like wtf.
    Thanks for the help btw, this project has been really fun it's going to look bomb when it's done.
  2. jcsd
  3. Jun 17, 2011 #2
  4. Jun 17, 2011 #3
    In years gone by, there was a craze for lights that flashed to the music. Those used a group of bandpass filters, about four or five, and level-threshold detector circuits for each. (think LM339 comparator)
    Anyway, most of these were not very good as they either failed to react, because the volume was too low, or simply went on all the time, when the volume was too high.

    Now's a good time to ask yourself some questions:
    Do you want multiple effects for multiple frequencies?
    Do you want patterns or sequences?
    Do you want the lights to flutter brighter and softer with the bass, or flash on the beat?
    Are you happy with they sensitivity issue (must be a certain volume range), or would you like it to work the same at high and low levels?

    Think through these questions, and perhaps I can toss together a starting circuit for you to bread board ;)

  5. Jun 18, 2011 #4
    Hah you know after reading your input, and thinking about it a bit more, I think this would be too much work for just UV LED's. I mean, if I was going to use blue or green ones with high mcd outputs it would be phenomenal, but I really want to stick to the UV paint and a rocker switch for on/off, maybe even a dimmer switch as well. I think the lack of reliability in the circuits combined with the low light output of the UV LED's isn't worth it.

    But something is still picking my brain a little. With dimmers specifically made for LED's, does the decrease in voltage react on a logarithmic scale when it approaches the voltage cutoff? Because I've seen some LED circuits that can go way dimmer than I could ever achieve in lab because the cutoff is so sensitive.

    Anyway, thanks for the info, I'll post some pics when it's done. Gotta get on my art buddy's *** to make me a sweet design that I can reproduce with acrylic paint.
  6. Jun 18, 2011 #5
    Yes, the Led's can cover a very broad range by controlling their current. From one batch to another, they tend to vary in output and this is most notable when they are dim, even though the output is supposed to be in proportion to current.
    There's a number of "switching regulators" to vary their dimness, but if you have power to spare banging a woofer, then you have access to enough power to simply regulated the LEDs with constant current or switch them with a simple ballast resistor in series.

    If you have visions of UV driven art, I'd ignore issues with the UV diodes and just go for it. You can always drive them more gently, heat sink them better, or just replace them to make up for life issues. Art is art. If you have to throw the rest out the window to get at what's driving you, then go for it.

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