Protip: Using a sub? Plug your mains

It seems the high pass filter should be enough.  I have read that plugging ports can mess with the speaker performance intended by the designer.  Could plugging the ports affect frequencies above the intended level at which the mains cross over to the subs?  I guess the only way to know is to try it. 

@mitch - It is true that you can't just willy nilly pick to port or not, and the size of a cabinet to ensure optimal performance. In terms of the overall frequency response, you are only changing the lower part of the woofer's response.  The upper part is dominated by other factors.  The big benefit is reduction in distortion by minimizing excursion, an especially important thing in 2-way designs as it can affect the clarity of the midrange a great deal.

The other big benefit is ths woofer will distort less at higher output.

A line level crossover, when significantly higer than the port tuning frequency, should be enough. :)

@erik_squires How does plugging the port keep the amp from trying to play down low? I don't have any high or low pass filters in my system. I want to try your suggestion but can you explain why physically plugging the port will change the amp's output? I realize it will change the outcome, but why would it change the out put?

@erik_squires 

You recently accused me of vague unprovable positions and a complete lack of evidence. Don't you think its hypocritical to claim without evidence that there is a reduction in distortion and excursion by plugging the port? Let us all see some evidence of this claim. None of us want to risk damaging our expensive speakers by following your advice.

You have also claimed that:

This combination increases the dynamic range, and reduces distortion, especially when used with a line level high pass filter.

What evidence do you have that using a line level high pass filter and then plugging the port brings additional benefits than just using a high pass filter alone?

It also often makes integrating the subs easier thanks to less overlap. 

Does it? Do you have any evidence of this ease with which the sub can be integrated? Or should we just take your word for it? Isn't it hypocritical of you to accuse me of being vague when you are being just as vague when you say that it becomes easier to integrate the subs?  Would this integration be done by ear or is it measurable?

My sub has the ability to contour/adjust the levels of specific audio bands (parabolic equalizer) so that I can integrate the sub with my mains.  With the use of a microphone, I can plot the frequency response of my room.  Not sure what the benefit would be with plugging the rear ports. 

@erik_squires Wrote:

Protip: Using a sub? Plug your mains

I would not block ports on my main speakers without first asking the manufacturer's advice. Blocking the ports would change the tuning frequency of the speakers. Keep in mind, if your speakers did not come with port plugs the woofers may not be designed to use them. 😎 See below:

Mike