How Dose A Port

[fischy fisch]

can any one help explain a port to me and how tuning affects it and all the other good stuff

plz pm me

[Guest]

http://en.wikipedia.org/wiki/Bass_reflex

"type of loudspeaker enclosure that uses the sound from the rear side of the diaphragm to increase the efficiency of the system at low frequencies as compared to a typical closed box"

the more amount of port, the higher the tuning will be, the less amount of port the lower the tuning will be.

http://subwoofertools.com/calculator_displ...mp;sheet_size=0

in that link i used a 12" Fi BL with a box tuned to 30hz, notice the amount of space inside the 2 bends in the port and the response graph at the top. notice the little flat bump at around 30hz also.

here is the same box tuned to 40hz, http://subwoofertools.com/calculator_displ...mp;sheet_size=0 . notice how this time the bump is around 40hz and more space in the port.

tuning a box to different frequencies, like 30hz, 35hz etc, will change how it sounds and what notes it will play.

tuning a box to a low number like 30-32hz will have great low output but will sacrifice upper bass, around 60-70hz. tuning a box to a higher number like 40hz will have terrible low output but insane high frequency output.

tuning a box lower will make it a little quieter, but have greater low note output and lower high note output. a higher tuned box will be louder in general, especially at the higher frequency's but no so much at the lower notes.

if you play a note that is under the box tuning, it will "unload" or pretty much bottom out extremely easily if your not careful, thats why 99% of subwoofer amps come with a Subsonic filter which filters out frequencies below a set point (you set the point of the freq. cutoff)

[DHFHades]

http://en.wikipedia.org/wiki/Bass_reflex

"type of loudspeaker enclosure that uses the sound from the rear side of the diaphragm to increase the efficiency of the system at low frequencies as compared to a typical closed box"

the more amount of port, the higher the tuning will be, the less amount of port the lower the tuning will be.

http://subwoofertools.com/calculator_displ...mp;sheet_size=0

in that link i used a 12" Fi BL with a box tuned to 30hz, notice the amount of space inside the 2 bends in the port and the response graph at the top. notice the little flat bump at around 30hz also.

here is the same box tuned to 40hz, http://subwoofertools.com/calculator_displ...mp;sheet_size=0 . notice how this time the bump is around 40hz and more space in the port.

tuning a box to different frequencies, like 30hz, 35hz etc, will change how it sounds and what notes it will play.

tuning a box to a low number like 30-32hz will have great low output but will sacrifice upper bass, around 60-70hz. tuning a box to a higher number like 40hz will have terrible low output but insane high frequency output.

tuning a box lower will make it a little quieter, but have greater low note output and lower high note output. a higher tuned box will be louder in general, especially at the higher frequency's but no so much at the lower notes.

if you play a note that is under the box tuning, it will "unload" or pretty much bottom out extremely easily if your not careful, thats why 99% of subwoofer amps come with a Subsonic filter which filters out frequencies below a set point (you set the point of the freq. cutoff)

sweet...can you throw one up for an FI BL15?