rattle/buzz in bass reflex port

[Astro]

i have a rattle in onr of the ports on the back of my speaker, it is the actual plastic cylender port that was rattling against the hole of the speaker i think. I pulled it out and the rattle/buz went away, my question is , is it ok to keep the port out ? Am i going to loose performance in anyway and is it bad to do this? also noticed alot more air firing out of it now. Also the speaker seems to have more bass now, maybe beacuse it is firing more air towards the back wall, (the speakers are about 40-50cm off the back wall.

[bjornb17]

i think the ports usually have specific shapes that are optimized for a certain frequency response and reduced port turbulence.

i think that some brands probably just put ports on their speakers without looking too much into the science of it.

Maybe you could just glue it back on?

[kexodusc]

i think that some brands probably just put ports on their speakers without looking too much into the science of it.


I've seen some incredibly cheap speakers made but they always effectively use porting.
There's really not that much to the "science" of it.
You are correct, the tuning frequency of the entire system is affected by the volume (and to some extent surface area) of the port. Paradigm uses about the cheapest ports I've seen in some of their speakers, the cardboard tubes you find at the center of a roll of toilet paper. But those work fine.

Astro:
By reducing the port size that much you can raise the tuning frequency of the cabinet. While your speakers might sound like they have more bass, they just have a large bass spike across a small band of frequencies, but the response is no longer flat, nor as deep. What's worse, it's incredibly mismatched with the other speaker.

You run the risk of damaging your speaker at higher levels by removing the port as such. Depending on the woofer, it's very possible that you've signficantly reduced the power handling of the speaker by pushing up the point where the woofer reaches maximum excursion. Not really a good idea.

If possible, glue the port tube back into place. You can buy that plumber's adhesive/sealant "Goop" which is ideal for sticking port tubes to speaker walls.

[Astro]

I've seen some incredibly cheap speakers made but they always effectively use porting.
There's really not that much to the "science" of it.
You are correct, the tuning frequency of the entire system is affected by the volume (and to some extent surface area) of the port. Paradigm uses about the cheapest ports I've seen in some of their speakers, the cardboard tubes you find at the center of a roll of toilet paper. But those work fine.

Astro:
By reducing the port size that much you can raise the tuning frequency of the cabinet. While your speakers might sound like they have more bass, they just have a large bass spike across a small band of frequencies, but the response is no longer flat, nor as deep. What's worse, it's incredibly mismatched with the other speaker.

You run the risk of damaging your speaker at higher levels by removing the port as such. Depending on the woofer, it's very possible that you've signficantly reduced the power handling of the speaker by pushing up the point where the woofer reaches maximum excursion. Not really a good idea.

If possible, glue the port tube back into place. You can buy that plumber's adhesive/sealant "Goop" which is ideal for sticking port tubes to speaker walls.


hey thanx for the advise btw
ok i have another problem, the servise technician has stuck some very fine cotton wool inside the speaker to stop the noise inside from bouncing around, only prob is his stuck it infront of the port tubes, which means its covering the ports. Is this ok or should i rip it out?

[kexodusc]

Unless you know for a fact that plugging this port is encouraged (preferrably by the manufacturer), I'd take it out....you can do it on most speakers and get away with it until you crank the volume up really high, and on some even that won't hurt anything, but if you don't know 100%, I'd err on the side of caution. Besides, the speaker wasn't meant to be listened to with a port plugged, or it would have had a sealed cabinet to begin with.

Can you get inside the cabinet? Fixing a port isn't that hard.

[Astro]

Unless you know for a fact that plugging this port is encouraged (preferrably by the manufacturer), I'd take it out....you can do it on most speakers and get away with it until you crank the volume up really high, and on some even that won't hurt anything, but if you don't know 100%, I'd err on the side of caution. Besides, the speaker wasn't meant to be listened to with a port plugged, or it would have had a sealed cabinet to begin with.

Can you get inside the cabinet? Fixing a port isn't that hard.

I can only get inside through the port hole. That is enough to take the small packing out the guy put in , and also to reseal the port tube.
The other speaker dosnt have the packing where the guy put it in, so i doubt the manafacturer recomended it.
so your saying you can plug the back of the port tubes with the stuff the doods put in and u can get away with it? will it alter the way the speaker sounds etc compared to the other one? because if it will ill have no hesitation then to remove it.

[kexodusc]

Generally ported speakers aren't meant to be plugged...even a bit of blockage will screw things up some.
Some speakers can be plugged though optionally...if your manufacturer doesn't recommend it or sell plugs, I wouldn't do it...if you aren't sure, don't.