Why must the cabinet port be either on the front or back of the cabinet?
Does not the front port placement add a distortion to what is heard? For you are hearing reflections from within the box coming out from the port.
Placing the port in the back? Doesn't that cause problems with reflecting off a wall and adds another kind of distortion if the speaker can not be moved far enough away? Why not have a port on top? Or, on the side(s)of the cabinet? Has anyone ever done this?
Does not the front port placement add a distortion to what is heard? For you are hearing reflections from within the box coming out from the port.
Placing the port in the back? Doesn't that cause problems with reflecting off a wall and adds another kind of distortion if the speaker can not be moved far enough away? Why not have a port on top? Or, on the side(s)of the cabinet? Has anyone ever done this?
Port borne audio is going to be omnidirectional no matter what side of the cabinet it is placed on.
So, any port induced distortion products or noise will be heard (more or less) equally as well.
Placing a port on the top is just an invitation for objects to fall into the cabinet or if they are liquid, be poured/spilled into that opening.
Or, if it is Homer Simpson, place his arm into the port and make a fist.
So, any port induced distortion products or noise will be heard (more or less) equally as well.
Placing a port on the top is just an invitation for objects to fall into the cabinet or if they are liquid, be poured/spilled into that opening.
Or, if it is Homer Simpson, place his arm into the port and make a fist.
Useful output from the port is really quite low - centered around the tuning frequency, which is almost invariably going to radiate omnidirectionally from the woofer anyway, meaning that discussions about rear reflections are pretty much moot.
However, there is probably a slight reduction in noise and harmonics if the port is not at the front.
Port noise complaint? (When will that stop being funny?)
If there's midrange inside the cabinet, it will be audible at the port (and it's just a question of how close you need to be to hear it.)
Port chuffing is audible but can be minimized with a larger diameter (and length) port.
But a ported speaker is such a bad compromise that one should hide away the port on the rear (or bottom) out of shame...
If there's midrange inside the cabinet, it will be audible at the port (and it's just a question of how close you need to be to hear it.)
Port chuffing is audible but can be minimized with a larger diameter (and length) port.
But a ported speaker is such a bad compromise that one should hide away the port on the rear (or bottom) out of shame...
This is correct. In some cases, however, a design is so incompetent that placement on the back becomes essential. Take the Epos ELS-8:
http://www.avhub.com.au/files/Epos_ELS8_Speakers_Review_LoRes.pdf
Its port emits a loud whistle at 1 kHz, at a mere -15 dB below full output. How on earth they managed to conjure up such a thing is totally beyond me. Maybe they stuck a piccolo in the port!
That is why I may go back to the NHT Absolute Zeros when I get an amp with more power. One of the few sealed boxes available on the market and so happen to make an excellent speaker. Everyone is porting these days.
http://www.nhthifi.com/site/pdf/Absolute Zero iBrochure.pdf
Alright, but my smear campaign starts with the ported box.
(open baffle is a box? really?)
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It might not be very deep, but most I've ever seen are still cubic objects that have height, width and depth, even if the depth is only the thickness of the baffle
i had speakers with port on top , and i liked the result , bass was clean and port noise was low , the speakers were 4 feet away from the ceiling and filled the room with bass.But since i made my own sealed boxes i never wanted ported cabinets again , not even for subwoofer.bass on sealed speakers sounds tighter to me.
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Hello GeneZ,
Several years ago, just for fun, to answer the same question, I cut a rectangular hole in an interior wall of my house while re-modeling, and then press-fitted a 7-inch 2-way with a rear port into that hole.
Next, I closed the door and could hear only the sound from the port, as the drivers fired into the adjacent room... Wow, that sounded bad! It produced a lot of harsh sounding midrange in addition to bass...not for me...not even in back!
BTW, no functional stuffing scheme I tried could fix this problem.
HTH,
David T
Several years ago, just for fun, to answer the same question, I cut a rectangular hole in an interior wall of my house while re-modeling, and then press-fitted a 7-inch 2-way with a rear port into that hole.
Next, I closed the door and could hear only the sound from the port, as the drivers fired into the adjacent room... Wow, that sounded bad! It produced a lot of harsh sounding midrange in addition to bass...not for me...not even in back!
BTW, no functional stuffing scheme I tried could fix this problem.
HTH,
David T
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