Anyone try stuffing their ports?

Response to the "leave it as designed" argument. Simply make a list of the designer's problems:
1. Which shape, size and furnishings in the room?
2. Used with what equipment?
3. How close will actual production be to my specs?
4. What safety factors must I provide so that abusive idiots will not return the item and reduce profits thereby putting me out of a job??
5. What will the reviewers say?
Compare these with my problem of simply how to make it sound best to me in my room with my stuff.
My experience has been that the best sound is achieved either when a good dealer does the whole setup, or when the consumer tries every suggestion that does not result in personal injury.

Rhljazz - Overall I am very satisfied with the improvements the NOS tubes have provided - they are NOT coming out. However, they do seem to provide deeper and bigger bass so am wondering if this is causing any issues with my drivers (only 6.5" poly) as I think mid bass is sounding slightly distorted now - not exactly positive as have not had enough time lately to properly evaluate. Since I have a pair of powered subs, which never break a sweat as they are rolled in very low freq., am curious what it might sound like if they were given a more prominent role in the mix. Which I intend on trying just for fun and thought one way to do this would be to stuff the ports and raise the x-over. But I certainly do not want to mess up the mid freqs. the mains supply, or the speaker's ability to image well. Thought I'd get some input prior to trying (I am not a tinkerer so prefer to have only a few options to try rather than running the gamut myself.)

I would have first tried pulling them further out into the room to see how that affected, but they are already pulled as far out as they can be so this is not an option.

My HSU subwoofer, operating on the same principles as all other ported bass enclosures comes with a SINGLE dense foam plug for one of TWO ports.
The sub is provided with a switch for 1port / 2port operation. I don't know what the internal circuit changes entail.
The manual says the switch is for 'Maximum extension mode' and 'Maximum output mode'

Not that it matters, but I run maximum extension mode, since I rarely go to nose-bleed levels.

You have'nt included a full system picture but it appears that your subs are to the outside of your speakers. One tweak that might make a difference is to put your subs inside the left/right speaker position and the exact distance from the listening position.