Question about max SPL at tuning frequency

Discussion in 'Archived Threads 2001-2004' started by Justin Ward, Jan 2, 2003.

  1. Justin Ward

    Justin Ward Supporting Actor

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    I tried to post this earlier but the server was down and I lost it. What limits the max SPL output of a sub at the tuning frequency. For example, with a high powered amp(500 watts)would a Tempest bottom out at its tuning frequency with enough power or would it simply go as loud as the amp would allow?
     
  2. Shawn Solar

    Shawn Solar Supporting Actor

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    Well at tuning the sub's excursion drops dramatically as the port is mostly creating the sound. My sub moves very little at tuning but you could shoot a nerf ball out of the port. x-max is actually higher at say 30hz. The port has a 18db rolloff lowpass and high pass which is why a ported cabinet essentially works as a sealed enclosure above tuning. also a ported sub is usaully 3-10db more effecient than the same sub in a sealed enclosure at the tuning frequency as long as tuning is close to fs. now below tuning the sub has a very steep rolloff and as the woofer and port shift out of phase excursion rises dramatically. In a lot of cases a sealed and a ported sub have close -10db figures but the -3db output can usually be an octave apart.
     

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