Plugging speaker ports...any harm?

[pearsall001]

Just a question out of curiousity. Some speaker designs are sealed & others are ported. Now granted, the designer had specific goals in mind for their performance by choising one of the two designs. What is the real difference between the two? Does a ported speaker provide more bass than a sealed speaker? Does one design perform better than the other, & if you were to stuff the port holes how would it effect the speakers performance? Could that possible harm the speaker? I think it's all about moving air inside the cabinet. In a sealed design where does the air go or maybe it doesn't. I guess either design has it's +/-. Any thoughts?

[Thelonious Funk]

I don't know about harming the speaker, I'll let someone else answer to that... but I know it takes less power to move a speaker when it is ported than when it is closed.

[Kevin D]

Ports can also be tuned to boost certain frequencies. Plugging the ports will reduce this boosting. A lot of manufacturers actually include plugs for when you have to have the speakers in cabinets or close to walls (which generally boost the same frequencies the ports do).

I usually use a sock-tube in testing if they didn't include a plug. You won't hurt anything. My SVS subs actually have three ports. Plugging one of them extends the output down another 8hz, but reduces the output by 3db.

Kevin D.

[Jack Gilvey]

I don't know about harming the speaker, I'll let someone else answer to that... but I know it takes less power to move a speaker when it is ported than when it is closed.

In the area where the port is active, it actually takes a lot more power to move the speaker a given distance than with sealed, although you get more output, due to the port's resonance...that's the whole idea behind reflex.

[JonMarsh]

Drivers have different Theil/Small parameters depending on whether they're designed for a sealed application, ported, or dipole. The Qts is lowest for the reflex type, and if you convert it to a sealed design by plugging the port, it will probably be over damped and have less bass output than a sealed system of the same size designed that way.

In some circumstances you may find that desirable, such as if you've placed the speaker in a corner too lose to walls, and it becomes bass heavy. Normally, a better solution is positioning the speaker properly.

JMO.