The woofer is a 12" driver of a Klipsch SW-12 that has its own internal amplifier in a closed enclosure with a passive 12" radiator.

I tested the whole subwoofer with the driver out of the enclosure a few times. Its spider is partially off the voice coil filler now.

I'm wondering if testing this way caused this damage or the amplifier caused it by sending abnormal signals.

In other words, do most closed enclosure provide damping effects significant enough to restrict overexcursion of the voice coil?

  • Well, this depends on the type of testing you did. A woofer outside of an enclosure is unlikely to reach the same output to amplitude. If you are trying to test the loudness outside of the enclosure then it is entirely possible that would would overdrive it and cause mechanical damage, since your would have to push it much harder to get desirable volume.
    – user9881
    Feb 8, 2017 at 17:43
  • 2
    I'm voting to close this question as off-topic because this is about electronics repair not sound design
    – Tetsujin
    Feb 8, 2017 at 18:38

1 Answer 1


Testing it outside the cabinet at low-level won't harm the woofer, but at higher level, the air movement not being controlled by the box can result in weird air flow that will force against the woofer and might damage it. If that damage happened at low level, then your amp might be faulty.

  • I may have played Enya's CD too loud. There was a good thump in one track.
    – zeron
    Feb 8, 2017 at 17:48
  • Probably what happened. Just keep in mind that low frequencies are pretty much omnidirectional and their wavelength is so long that the air pressure is built everywhere around it. If the speaker is inside a cabinet, then the energy is kept inside and, most of the time reused by a bass-reflex or a passive woofer design.A woofer doing low end in a completely sealed box will also get damaged because the air cant move. When the speaker moves forward, it creates a negative pressure inside that will pull on the woofer and when it moves backwards, it compresses the air that will push the other way Feb 8, 2017 at 17:57

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