Nice speakers, however, I am not a fan of ports. If any, front facing for direct radiation of bass fundamentals and their overtones supporting definition/imaging. Not indirect diffuse multi-reflected sound waves as you have now.
You want to test/listen in 2 channel mode, not surround sound, no center, no sub, no surrounds, do that last.
As Eric suggested, I would start by temporarily closing the rear ports. It will not effect the mid and tweeter. It will effect the two 8" drivers.
Play something with distinct moments of highs, mids, and bass first, then temporarily cover the ports, what differences?
Now, are you wanting extended directional bass, or simply extended bass?
My home theater, I use 1 self powered sub, in a non-directional way, to simply add the dinosaur stomp in Jurassic Park, that kind of thing.
For music, bass is/can be stereo/directional, that requires a pair of front firing subs located adjacent to the mains. Self powered. Now you will know where the bass player is standing.
Balance the subs with the mains only, i.e. 2 channel with bass extension. Then, add the center and surrounds. Avoid too much surround volume. Generally (i.e. not specific helicopters from the rear left) you should not be aware of them until you turn them off and the sound collapses to the front. Many people have them too loud.
Keep in mind, much content has been altered along the way, If something is not sounding great, I switch to 2 channel mode, often find it better.
You want to test/listen in 2 channel mode, not surround sound, no center, no sub, no surrounds, do that last.
As Eric suggested, I would start by temporarily closing the rear ports. It will not effect the mid and tweeter. It will effect the two 8" drivers.
Play something with distinct moments of highs, mids, and bass first, then temporarily cover the ports, what differences?
Now, are you wanting extended directional bass, or simply extended bass?
My home theater, I use 1 self powered sub, in a non-directional way, to simply add the dinosaur stomp in Jurassic Park, that kind of thing.
For music, bass is/can be stereo/directional, that requires a pair of front firing subs located adjacent to the mains. Self powered. Now you will know where the bass player is standing.
Balance the subs with the mains only, i.e. 2 channel with bass extension. Then, add the center and surrounds. Avoid too much surround volume. Generally (i.e. not specific helicopters from the rear left) you should not be aware of them until you turn them off and the sound collapses to the front. Many people have them too loud.
Keep in mind, much content has been altered along the way, If something is not sounding great, I switch to 2 channel mode, often find it better.