Doorway Subwoofer


We’ve seen some crazy speaker builds in the past (massive folded horns for example). [DiscoJones] wanted to build a set of speakers that could reach very low frequencies and be very efficient. Instead of constructing a large box, he built a baffle that could be placed in a doorway and use the blocked off room as an enclosure. It has eight 12inch subwoofers, eight midrange drivers, and four tweeters. The speakers are fairly cheap and he built a simple crossover to help them work a little better together. The goal was always deep bass though, so don’t expect very high fidelity from a setup like this.

26 thoughts on “Doorway Subwoofer

  1. As cool looking as this is, there’s some math behind how large the enclosure needs to be for efficient sound production. I suspect that this is more for the visual shock factor.

    He seems to have put some thought into it, but as far as speaker design goes it seems that even the smallest room would be too large. I’m no expert though. That being said, I want one… or two.

  2. @calebkraft

    An infinite baffle setup has no box, or at least one big enough to not dampen the suspension of the drivers by compressing the air inside of the box. the only things to worry about would be the room being too small, not properly separated from the back side of the baffle, or why there are eight mid ranges and four horns in the back of the room.

  3. Like some other people said, this is only going to sound good if he actually matched these speakers with the room size. The door is probably going to vibrate too.

    Also is this really a subwoofer or just stereo speakers in a door? Why would he have midrange and tweeters on a subwoofer and more importantly why would there be two hookups? Subs should be mono.

  4. Loudspeaker design lesson: This is an infinite baffle setup. The drivers used in this type of install typically have very low mechanical compliance or Cms in theil/small parameters. This means they are not dependent on using air pressure to properly damp their suspensions. As such, an infinite baffle setup isn’t dependent on a fixed enclosure volume which limits frequency response. Infinite baffle setups have a flat response that drops quite low and crosses over well into midbass frequencies.

  5. my thoughts as an audio engineer…

    idea: ok-
    components: crap
    crafting: pretty well done
    usability: none
    why a stereo pair only inches apart…useless !

    get a good (horn) sub for cheaper…nobody needs more !

    got a 18″ cerwin vega located in the corner, using only 10% of what it’s capable of.
    needs a good crossover and filtering of course !
    absolute killer in ht setup…some of my friends almost got a heart attack :)

  6. @defex – the rotary sub should be able to replicate whatever (low) frequency sounds you put into it, the only difference between its method of vibration production is axial rotation of blades, rather than linear movement of a cone – assuming you’re using similar drive circuitry and the servos for altering the blade pitch are torquey/powerful enough you should have no problems superimposing frequencies..

  7. @defex some more…

    I’m fairly sure I’ve seen a test vid online of one (possibly not the original) hooked up to a DVD, the tester noting there were sounds at <20hz that they never "felt" before lol.

  8. dude .. VERY GOOD idea I’m sure he had intentions of just making it loud and the stereo part who says it has to be stereo .. yeah it has 2 channels 2 mono-blocks to a mixer or an electronic crossover make a great DJ setup just carry the door. lol screw 100’s of lbs of speakers when a door panel and a spare room will work, house party

  9. The expensive part of speaker set up is for woofer and sub woofer, this method minimises the expense there, mid and tweeter setup is directional, so it had to separate and place strategically. Care on the banging and air sealing the door is understood.

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