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<blockquote data-quote="Bennett Prescott" data-source="post: 148372" data-attributes="member: 4">Re: 60 Degree&nbsp; DIY Mid Hi[ATTACH]154550[/ATTACH]If you like. In a subwoofer attack and release times of 30 seconds or longer wouldn&#039;t be un-warranted, but that requires a lot of envelope tracking so the 5-10 seconds that most limiters allow gets the job done and sounds OK. I&#039;ve attached a capture of the LSI power test data from one of our 18&quot; woofers, as you can see it takes about 7 minutes for the coil to come to temperature - by which time it&#039;s about doubled in impedance (i.e. is now effectively 16Ω instead of 8Ω). This is with AES rated power input, which should be a long-term survivable power level if excursion is kept under control.All that says nothing about mechanical constraints, these power tests are in free air. Add a cabinet and the limits of the woofer will not be the same. A basic thermal limiter will save your bacon in nearly all situations. Unfortunately, excursion cannot be limited with a simple peak limiter: your best bet is to use an appropriate high pass filter (e.g. 2nd order at the box tuning frequency for a normal direct radiator). In a reasonably designed box, between the thermal limiter and the high pass filter, it ought to be pretty difficult to exceed the capabilities of the woofer. More importantly, with such a system the first indication of distress will likely be given by the woofer so an experienced operator will know where the limit lies. <a href="http://www.klippel.de/our-products/controlled-sound.html" target="_blank">Klippel have done some significant research</a> recently into a method for reliably limiting excursion, primarily for small devices, but I have not yet seen a pro audio application of it. To my knowledge there is no widespread tool that will limit excursion directly.</blockquote>

[QUOTE="Bennett Prescott, post: 148372, member: 4"] Re: 60 Degree DIY Mid Hi [ATTACH=CONFIG]154550.vB5-legacyid=14195[/ATTACH]If you like. In a subwoofer attack and release times of 30 seconds or longer wouldn't be un-warranted, but that requires a lot of envelope tracking so the 5-10 seconds that most limiters allow gets the job done and sounds OK. I've attached a capture of the LSI power test data from one of our 18" woofers, as you can see it takes about 7 minutes for the coil to come to temperature - by which time it's about doubled in impedance (i.e. is now effectively 16Ω instead of 8Ω). This is with AES rated power input, which should be a long-term survivable [U]power[/U] level if excursion is kept under control. All that says nothing about mechanical constraints, these power tests are in free air. Add a cabinet and the limits of the woofer will not be the same. A basic thermal limiter will save your bacon in nearly all situations. Unfortunately, excursion cannot be limited with a simple peak limiter: your best bet is to use an appropriate high pass filter (e.g. 2nd order at the box tuning frequency for a normal direct radiator). In a reasonably designed box, between the thermal limiter and the high pass filter, it ought to be pretty difficult to exceed the capabilities of the woofer. More importantly, with such a system the first indication of distress will likely be given by the woofer so an experienced operator will know where the limit lies. [URL="http://www.klippel.de/our-products/controlled-sound.html"]Klippel have done some significant research[/URL] recently into a method for reliably limiting excursion, primarily for small devices, but I have not yet seen a pro audio application of it. To my knowledge there is no widespread tool that will limit excursion directly. [/QUOTE]

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