Reply to thread

Message

<blockquote data-quote="helotaxi" data-source="post: 355585" data-attributes="member: 550915">Most will work IB you just can&#039;t power the crap out of them.&nbsp; Only the Qtc of the driver itself is keeping the excursion in check.Most any configuration can be made to give accurate bass.&nbsp; Ported designs, by virtue of the port, will not provide truely linear response.&nbsp; There is a reinforcment of the frequencies right around the Fb.&nbsp; That is not accurate.&nbsp; The sub itself plays a huge role in the overall accuracy of the bass.&nbsp; Matching the sub to the enclosure is the rest of the equation.It is also said that ported plays lower.&nbsp; To a point this is true.&nbsp; In an anechoic environment, the F3 of an optimal ported box is lower than its sealed counterpart.&nbsp; The difference is in the rolloff.&nbsp; A sealed box rolls off at 6 dB per octave while ported rolls off at 12.&nbsp; So you just tune lower on the ported box right.&nbsp; Not so easy.&nbsp; The system Q changes when you mess with enclosure size and tuning and accuracy suffers as a result.&nbsp; Also, the car is anything but an anechoic environment.&nbsp; Cabin gain works at about 6 dB per octave, coincidentally the same rate that a sealed box rolls off.&nbsp; This actually works to flatten the in-car response of a sealed box system.&nbsp; In a ported system the cabin gain tends to over accentuate the low frequencies and make the bass sound exaggerated.&nbsp; Again, not accurate.Last point, the basis of your whole argument to begin with is that a sealed box overdampens the cone of the sub.&nbsp; Well as a ported enclosure nears resonance, the motion of the cone is much more restriced than in a sealed system.Take the subjectivity out of the equation.&nbsp; Overlay a RTA readout of the signal with the RTA readout of in-car frequency response for both a sealed and ported system.&nbsp; All we are interested in is the sub-bass region say 70 Hz and below.&nbsp; Run a few delay plots as well.&nbsp; Tell me what you find.It doesn&#039;t take an audiophile to hear group delay, BTW.</blockquote>

[QUOTE="helotaxi, post: 355585, member: 550915"] Most will work IB you just can't power the crap out of them. Only the Qtc of the driver itself is keeping the excursion in check. Most any configuration can be made to give accurate bass. Ported designs, by virtue of the port, will not provide truely linear response. There is a reinforcment of the frequencies right around the Fb. That is not accurate. The sub itself plays a huge role in the overall accuracy of the bass. Matching the sub to the enclosure is the rest of the equation. It is also said that ported plays lower. To a point this is true. In an anechoic environment, the F3 of an optimal ported box is lower than its sealed counterpart. The difference is in the rolloff. A sealed box rolls off at 6 dB per octave while ported rolls off at 12. So you just tune lower on the ported box right. Not so easy. The system Q changes when you mess with enclosure size and tuning and accuracy suffers as a result. Also, the car is anything but an anechoic environment. Cabin gain works at about 6 dB per octave, coincidentally the same rate that a sealed box rolls off. This actually works to flatten the in-car response of a sealed box system. In a ported system the cabin gain tends to over accentuate the low frequencies and make the bass sound exaggerated. Again, not accurate. Last point, the basis of your whole argument to begin with is that a sealed box overdampens the cone of the sub. Well as a ported enclosure nears resonance, the motion of the cone is much more restriced than in a sealed system. Take the subjectivity out of the equation. Overlay a RTA readout of the signal with the RTA readout of in-car frequency response for both a sealed and ported system. All we are interested in is the sub-bass region say 70 Hz and below. Run a few delay plots as well. Tell me what you find. It doesn't take an audiophile to hear group delay, BTW. [/QUOTE]

Verification