# Can I plug up my center channel port holes?



## thewire (Jun 28, 2007)

I have a Polk csi-40 center channel and with really heavy bass and no highs such as in fellowship of the ring I have a problem. It is powered by two powerful THX amps that are rated at a safe amount of power. I'm not wanting to change my setup at this time.

My other speakers don't have this problem but my center channel starts huffing and puffing out the port holes. Yes the volume is way up at -6db reference and +4db on the auto setup setting.

Can I just plug them up without damaging the woofers? I would luv to watch this movie all the way with no distortion or issues and this stands in my way.

Should I just not worry about it until upgrade time?


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## thewire (Jun 28, 2007)

I would not hold anyone accountable if they blew as a result I just want to know if it could most likely cause it to happen. It seems in my experience that it is easier to blow a driver without a port but I could be wrong.


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## Mike P. (Apr 6, 2007)

It won't damage the drivers to plug the port. The CSi40 has a silk/polymer composite dome tweeter but you say you don't have any "highs". Maybe you have a blown tweeter or a bad crossover. It could also be a bad channel from the receiver.


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## thewire (Jun 28, 2007)

What i meant was I can hear it when there is less in the high range. They do that in the movie on purpose and its very challenging. An example is when the hobbits are hiding under the tree next to the road and the creatures begin to crawl out. There is just no other noise to cover up the sound of air blowing out the port. I had to replace my tweeter (I use less power now 90W where before it was 125W at the tweeter:doh already with a regular one out of another brand dipole speaker but its the same size and works for now. The equalizer helps. Thank you for the quick response. Going to give the movie another try shortly.


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## Guest (Sep 25, 2007)

The ports are part of the low frequency loading of the drivers.
The volume of air in the port acts as a spring at the box tuning frequency and essentially does most of the work below that frequency.
Plugging the port essentially converts your ported speaker to a sealed box, resulting in a fourfold increase in cone displacement for every halving of frequency below resonance.

The short answer is that plugging the ports will probably reduce the low frequency power handling and dynamic range of the speaker.
The chuffing issue will be resolved, but harmonic and IM distortion might become audible at high levels, as the drivers are required to work outside their design parameters.


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## thewire (Jun 28, 2007)

I just re-setup with the auto-setup and had great results. It set my speakers to small and for the first time I did not get an error message to turn up my sub. I will see if I still have the problem with the port holes not plugged.


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## JCD (Apr 20, 2006)

Something I've heard tried was stuffing a port full of straws.. I have to be honest, I don't remember what it was supposed to accomplish, but I remember it was supposed to help "something".

Also, I don't think it would hurt your speaker to experiment with plugging the port -- I'd try and see if it makes it better. 

Two low tech tweaks that may help -- and won't cost much to try. I say go for it.

JCD


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## Guest (Oct 6, 2007)

Unless the manufacturer says you can I would not.Most likely having the center set as large was the cause.


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## John N (Jan 2, 2007)

thewire said:


> I had to replace my tweeter (I use less power now 90W where before it was 125W at the tweeter:doh already with a regular one out of another brand dipole speaker but its the same .


Your woofer(s) in your center channel may be playing louder than the "new" tweeter.


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