Port placement..

[GeneZ]

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?

[Loren42]

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.

[fatmarley]

Royd minstrels have their port on the side.

[454Casull]

Originally Posted by GeneZ

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?

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.

[GeneZ]

Interesting! Thank you. I listen near field. The problem I had with one ported speaker was that I could feel the wind on my face on colder nights. Turned it tweeter side down. Took care of it nicely.

[454Casull]

Sorry, when I meant "low" I didn't not mean in magnitude but in frequency.

Hope nobody was confused.

[GeneZ]

Originally Posted by 454Casull

Sorry, when I meant "low" I didn't not mean in magnitude but in frequency.

Hope nobody was confused.

Actually, I was not confused. Just wrong.

Thanks for clearing that up.

[Andersonix]

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...

[bbggg]

Originally Posted by 454Casull

there is probably a slight reduction in noise and harmonics if the port is not at the front.

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_E...view_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!

[fatmarley]

Originally Posted by Andersonix

But a ported speaker is such a bad compromise that one should hide away the port on the rear (or bottom) out of shame...

Too right ! Holes in speakers should be ilegal.