Doorbell transformer to break in speaker

Discussion in 'Amp Tech Center' started by mherrcat, May 16, 2019.

  1. mherrcat

    mherrcat Tele-Holic

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    Thoughts on using an 8V doorbell transformer to break in a 20 watt 8 Ohm speaker? I want to let it run all day while I am at work.
     
  2. printer2

    printer2 Poster Extraordinaire

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    I left one on for two months.
     
  3. Chunkocaster

    Chunkocaster Poster Extraordinaire

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    Sounds more annoying for the neighbours than just running music through it.
    Will it be chiming or just exciting the coil?

    Put Smoke on the Water and Freebird on a loop if you want to get at your neighbours.
     
    ftbtx likes this.
  4. brokenbones

    brokenbones Tele-Meister

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    Are you talking about running the chime or just the voltage? The chime should work. Generally you want the full spectrum of frequencies the guitar reproduces present when breaking in a new speaker. I imagine the chime would be pretty close and useable.
     
  5. RodeoTex

    RodeoTex Poster Extraordinaire

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    I don't think that would do so much except keep the coil energized.
    Maybe wire it up as a buzzer relay. That would give the speaker a workout
     
  6. boop

    boop Tele-Meister

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    Why not use a loop pedal and play some guitar playing through it?
     
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  7. ranjam

    ranjam Tele-Holic

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    Sorry, but you may not quite understand the point of the exercise. The goal is to soften the edge surround, to simulate years of moving in and out. You need a low frequency to get the edge moving; high frequencies come more from the center of the cone, and won't 'break in' anything.
    One way is to use a Variac or filament transformer. The filament transformer is a little on the low side for your speaker. You can get the basic idea, and a schematic on building a 'tool' to do this;

    http://www.tone-lizard.com/working-in-a-speaker/

    Uncle Spot had an online calculator to determine a 'safe' voltage for your speaker based on impedance and wattage. Sadly, Uncle Spot and his website aren't around, but the Wayback Machine is.

    https://web.archive.org/web/20151024082914/http://www.unclespot.com/speakerbreakin.html

    Your particular speaker would need 7.30VAC to try and soften up the surround. That's 33% of the rated power going through the speaker, so I don't fear a full 8VAC on the speaker. Make sure the speaker is facing 'up', and somewhere where that low drone won't drive anyone nuts.
     
  8. mherrcat

    mherrcat Tele-Holic

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    I did find that formula for calculating the voltage yesterday. I figured as well that 8V would be safe. My only concern was if running the transformer for about 12 hrs a day would overheat the voice coil or something.

    I have been running my iTunes music library from my home computer through the amp for two days now, but wanted to give the amp a rest. With a folded towel hanging over the front of the speaker and the amp in a spare bedroom with the door closed you can barely hear it outside the house; inside is another story...

    This is the transformer I was thinking of using; I believe it is available at Lowe's. It has multiple taps for different voltages; one is for 8VAC:

    upload_2019-5-17_9-31-1.jpeg
     
  9. jvin248

    jvin248 Poster Extraordinaire

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    .

    I'd up the humidity so you get more cone flex started, and run the radio on loud so you get a wide spectrum of noise. You might look into effectiveness of white or pink-noise on doing break-in (I remember something about that helping from years ago).

    Boil a big pot of water while you are getting ready to leave to steam up the kitchen, or put the amp in the bathroom while you take a shower and close the bathroom door with the radio running all day so the humidity softens those fibers and lets them flex more.

    Make sure you're neighbors are ok with all the racket.

    .
     
  10. ecoast

    ecoast Tele-Holic

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    I usually just use a 12-volt or 9 volt wall wart after doing the math...
     
  11. mherrcat

    mherrcat Tele-Holic

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    I thought about that, too, but wasn't sure about the current draw. If it would work safely, I have several I could use, and return the doorbell transformer I just bought at Lowe's.
     
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