Cheap Speakers Sound Good With Easy Open Baffle Design

If you’ve spent any time around audio gear at all, you’ll know that enclosure design is as critical as the speaker drivers themselves. [Frank Olson] demonstrates this ably, with his open baffle design for some cheap off-the-shelf speakers.

[Frank]’s aim was to do a comparison between using no enclosure, and an open baffle design, with a pair of 2″ full-range speakers. These drivers are nothing special; just a low-cost part that you’d find in any cheap set of computer speakers. [Frank] screws the drivers into a thin, flat wooden board, and then adds a supporting strut to allow the speakers to stand on their own.

The comparison makes it clear that even this basic baffle design makes a big difference to perceived sound quality. Bass is fuller, and the sound is far improved thanks to the baffle blocking out of phase sounds from the rear of the speaker.

It’s a technique that could prove useful to anyone quickly trying to rig up an audio setup for the workshop or makerspace out of leftover parts. We’ve featured similar projects before that espouse the benefit of enclosure design when using even very affordable speakers. Video after the break.

20 thoughts on “Cheap Speakers Sound Good With Easy Open Baffle Design

  1. I’ve often found a simple thin open sided sandwich, made from a ridged sound reflective material, seems to do pretty well to amplify the sound from a small speaker and bring out the depth of sound.

  2. I wanted to do similar thing and install some IP67 piezo buzzers under toilet seat so they can play chiptune while I’m… doing my thing but hell waterproof piezos are expensive!

  3. I wonder what the speakers by themselves would have sounded like if they were pointed at the mic instead of pointing up? Would that make a difference in the sound quality?

    1. The mic being as offaxis as possible is a rather poor demonstration but i guess thee speakers tipped over when placed on their side. It would have been louder, but only really noticably in the range above something like 10khz.

      The reason is that with lower frequencies the air will move from a high pressure zone more easily to the low pressure zone behind the cone compared to higher frequencies which will be blocked by the driver itself (therefore almost no translation of energy to the air volume in the room is possible).
      The simple barrier between the front and the back blocks that cancelling airflow and enables the speaker to actually move air in an extended frequency range.

      1. When the path from the front to the back of the speaker is longer than half the wavelength, the speaker starts to radiate instead of just moving the air around. That’s because the pressure peak just manages to reach the other side as the cycle reverses. Any longer and the pressure can no longer equalize within the cycle, so it stars to go out in waves.

        At 1 kHz the wavelength is around 34 cm. This thing has an uneven baffle that works down to about that on one side.

  4. Flawed testing.
    While I am sure the baffles improve the sound. the first test had speakers pointed UP, second test had speakers pointed forward (towards meter etc) Sound is direction.
    More appropriate test would have been speakers hanging in air or at least pointed the same way as close as possible. Speaker against the table also effect the sound vs the volume of space behind speakers in baffle test.

    Basically — too many variables/conditions changed at one time.

    1. Since I’m being censored again by the commenting system and can only post by replying to someone else…

      If you want a phase inversion to amplify the bass, you’d need a baffle it would need to extend 70 cm around the speaker to have the desired effect at 500 Hz. In reality the bass sound appearing is simply due to the fact that the music in question has a square-ish waveform in the bass, as identified by the sound, in which case the brain fills in the missing fundamental and interprets it as low frequency even though there’s very little of that going on.

      So the video is basically a gimmick.

      1. But such a nicely finished gimmick ;-)

        Luke is right. To have a baffle big enough to block 60 Hz bass waves from cancelling, you’d need a baffle 18 feet in diameter.

  5. An incredibly long video about cutting two holes in two pieces of plywood.

    That said, it’s a sham. In the first case, the speakers are not aimed at the mic, in the second case they are, and the plywood is acting as a soundboard. Then the music that’s playing doesn’t really have a bass – it’s a square-ish wave so the effect is about the brain inferring the missing fundamental from the sound that gets louder when the speakers are pointed towards the listener.

    In reality, to get a phase inversion by adding a baffle, the size of the board would need to be around 3.4 meters all around the speaker to have the desired effect at 100 Hz or 70 cm at 500 Hz. Those boards are way too tiny.

  6. Have some 18″ bass/mid drivers which almost don’t need a baffle to work as they’re so huge. Much fun. Planning on using one with a full tube Fender Champ to make a ridiculous combo amp.

    Anyhow, have used cardboard boxes with a hole in for an even more shoddy (and thus fun) open baffle.

  7. Reinventing the wheel, arent we? This may be archived next to the article about pressurized air in rubber tires inproving comfort on a bike. Or “placing proper dimensioned resistor in series with led prevents killing it”.

  8. Many years ago I was introduced to the concept of mounting speakers in a large baffle and ended up doing some experiments of my own with cheap drivers and cardboard and I was pleasently supprised.

    Whole there are some flaws in the method and testing inconsitencies in this particular video it is a method that does work.

    Even grabbing a cheap driver and litteraly jaming it into a piece of corrugated card will produce a significant improvement in the volume and bass response over a free driver. Its pretty easy to demonstrate.

    I found that the board should be around 3 times the diameter of the driver in question. Yes a proper enclosure is better but if you dont have the time or resources and need a quick dirty fix this is a good solution

  9. I’m a huge fan of dipole subwoofer builds. Yes, you will loose a lot of efficiency that way, but the improvement in sound quality makes it worth it in my opinion. Been having great sucess with ripole type subs lately. That being said, 2 inch speakers in an open baffle design simply won’t be producing much bass. There you really need an enclose. A well tuned horn perhaps.

  10. Not exactly a sham. A speaker on a board/baffle/cabinet will sound better than that naked speaker. I have a couple of long-throw 4″ speakers salvaged from a 27″ TV. The TV cabinet had some minimal ported enclosure around the speakers, yet it sounded pretty good for a cheap speaker.

    The title could be changed to “cheap speakers sound less bad with easy open baffle design”.

  11. You can always do what organ maker Baldwin did with an eight foot square of fairly thick plywood. There usually was room for that monster in an organ loft in a church installation. That was their way of getting good bass from four 15″ speakers in the center of the panel.

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