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<blockquote data-quote="Jimi77" data-source="post: 8877504" data-attributes="member: 673702">Now we&#039;re talking about 2 types of power handling - mechanical vs thermal.&nbsp; Power handling may increase in a sealed enclosure due to limiting cone travel.&nbsp; In the case of a ported enclosure, thermal power handling increases (at FB) because the port introduces a peak in impedance.&nbsp; So hypothetically, a 1 ohm sub could read 5 ohms at the port frequency.&nbsp; This allows competitors to blast a 2kw sub with 10kw from the amp and everybody &quot;ohs and ahs&quot; about how XYZ sub can take so much over rated power, when in reality the sub was really getting something closer to rated power.&nbsp; You can model the change in impedance in box building software - I&#039;m pretty sure winISD gives you the impedance curve based on the enclosure and you&#039;ll see it change as you alter the enclosure.&nbsp; You see some pretty impressive results from bandpass enclosures with small drivers because they have 2 peaks to play with.&nbsp; Bose made a really high q sub for OEM systems (~1.0), which is another way to play with impedance curves.&nbsp; The Q and highish FS on the sub allowed it get pretty loud for a wimpy OEM sub.&nbsp;&nbsp; The sub had a peaky impedance curve, then you cram it in small sealed enclosure and the impedance curve gets even more peaky.&nbsp; That allowed Bose to bass boost into the frequence and the sub had pretty impressive output for what it was.&nbsp; There was a thread about that sub on DIYMA if you want to learn a little more about how you can use impedance curves to &quot;cheat&quot; the system.</blockquote>

[QUOTE="Jimi77, post: 8877504, member: 673702"] Now we're talking about 2 types of power handling - mechanical vs thermal. Power handling may increase in a sealed enclosure due to limiting cone travel. In the case of a ported enclosure, thermal power handling increases (at FB) because the port introduces a peak in impedance. So hypothetically, a 1 ohm sub could read 5 ohms at the port frequency. This allows competitors to blast a 2kw sub with 10kw from the amp and everybody "ohs and ahs" about how XYZ sub can take so much over rated power, when in reality the sub was really getting something closer to rated power. You can model the change in impedance in box building software - I'm pretty sure winISD gives you the impedance curve based on the enclosure and you'll see it change as you alter the enclosure. You see some pretty impressive results from bandpass enclosures with small drivers because they have 2 peaks to play with. Bose made a really high q sub for OEM systems (~1.0), which is another way to play with impedance curves. The Q and highish FS on the sub allowed it get pretty loud for a wimpy OEM sub. The sub had a peaky impedance curve, then you cram it in small sealed enclosure and the impedance curve gets even more peaky. That allowed Bose to bass boost into the frequence and the sub had pretty impressive output for what it was. There was a thread about that sub on DIYMA if you want to learn a little more about how you can use impedance curves to "cheat" the system. [/QUOTE]

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