Good answer Karls.
As a general rule, the bigger the woofer that one uses, the sloppier the bass will be when ported. For reasonably "tight" bass, smaller woofers work better if you really must port the cabinet.
Since bigger woofers typically use bigger motor structures, they generate more reflected EMF. This makes it harder for the amp to load into and control the driver. Combining a lack of control over the driver with a lack of damping or "air spring" in the cabinet due to having a "blow hole" in it typically results in noticeable "sloppiness". Add a driver with a high Qms ( big impedance peak at resonance ) and you've got a real problem with "bloat". This is true for SS or tube based amps but tubes may have a harder time due to the lack of current needed to "muscle" the cone around. As such, it is best to avoid ported speakers and go for the quality of bass rather than the quantity of bass. Sean
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PS... Pmkalby's point about using a higher efficiency design is quite valid, as a speaker that is more efficient won't have to make as long of an excursion. The less excursion, the less reflected EMF and the easier the amp can load into & control the driver. As such, it's kind of a "catch 22" situation and you have to choose what you like best and what sacrifices you are willing to live with. You should still avoid ported speakers though : )
As a general rule, the bigger the woofer that one uses, the sloppier the bass will be when ported. For reasonably "tight" bass, smaller woofers work better if you really must port the cabinet.
Since bigger woofers typically use bigger motor structures, they generate more reflected EMF. This makes it harder for the amp to load into and control the driver. Combining a lack of control over the driver with a lack of damping or "air spring" in the cabinet due to having a "blow hole" in it typically results in noticeable "sloppiness". Add a driver with a high Qms ( big impedance peak at resonance ) and you've got a real problem with "bloat". This is true for SS or tube based amps but tubes may have a harder time due to the lack of current needed to "muscle" the cone around. As such, it is best to avoid ported speakers and go for the quality of bass rather than the quantity of bass. Sean
>
PS... Pmkalby's point about using a higher efficiency design is quite valid, as a speaker that is more efficient won't have to make as long of an excursion. The less excursion, the less reflected EMF and the easier the amp can load into & control the driver. As such, it's kind of a "catch 22" situation and you have to choose what you like best and what sacrifices you are willing to live with. You should still avoid ported speakers though : )