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What is clipping?

Discussion in 'Amps and Cabs [BG]' started by freshmeat1989, Mar 17, 2004.


  1. What in the world is clipping. Once I get this question anwered I'll delete the thread.
     
  2. This topic has been discussed to death on this forum. Click the "Search" button, and search for "clipping" and you'll find loads of threads on the subject.

    Then, if you have specific questions, we'll be happy to answer.
     
  3. Mcrelly

    Mcrelly

    Jun 16, 2003
    Minnesota, USA
    Here is some info from the link in Joris' signature....

    5.6. Distortion, clipping

    When a power amplifier is forced past its maximum output power, it will clip. This means the output voltage of the amp is equal to the supply voltage from the power supply and can't go any further. The peaks (positive as well as negative) of the signal are clipped off, hence the term "clipping". Clipping in itself isn't bad, neither for the amplifier nor the connected speaker(s). It's the compression of the signal that causes problems. When a signal is compressed (by clipping it) its average power increases, and may be over the amplifier's maximum thermal capabilities. Furthermore, a clipped signal loses low frequency content, due to the fact that low frequencies usually have a larger amplitude. Low frequencies get clipped first, so to speak. This means the high frequency content increases relatively, and this can damage tweeters (horns).

    Now a more technical story. A side effect of clipping that is often overlooked is the DC decoupling instability. Most amplifiers can't amplify DC signals (why would they need to?), so they are DC decoupled. This has a huge advantage for designers: the output offset adjustment can be done automatically by the amplifier itself, instead of adjusting it by hand at the time of manufacture. This self-adjustment relies on the fact that the amplified signal always has an average value of zero (equal power in both the positive and negative half of the signal). If the signal is non-symmetrical, as is the case with many musical instrument signals, clipping will occur at only one half (positive or negative) of the signal. As a result, the output offset adjustment starts to shift, as the amplifier will keep its output at a zero average. In turn, this causes a very low frequency (that of the adjustment cycle) at the output. This is often visible as a strong waving of the speaker cones. Needless to say, a speaker cone that moves this much, is prone to damage.
     
  4. Heh heh, I sometimes forget I wrote that...... whoops :oops: