Foam plugs for Proac Response 3.8?

I just bought a minty pair of Proac Response 3.8s here on Audiogon, and am finding that the bass is overloading my 13 x 28' room. Because of the way the room is set up, I need to listen in the short dimension (speakers positioned along the long dimension on either side of the fireplace), in about a 10' triangle.

The bass is a little too strong, and I can't move the speakers further away from the wall (about 2' of clearance now) as they're already in the nearfield.

Would putting a bit of light foam in the double ports help tone down the bass, or do I need to go with a smaller speaker?

P.S. I'm driving them with an Audio Research Vsi60 integrated with the new KT120s.

Thanks for any help and advice.
Easy enough to try it and see, isn't it?
Is the room sufficiently filled with enough items, such as a sofa, ottoman, bookcase, etc? Do you have carpet or something else? When I moved into my new house, my stereo system preceded all the furniture by a few weeks. In my listening room, the bass coming from my ProAc D28's sounded loose and untamed. Once I got my listening chair, ottoman, bookcase, and a few pillows in there, the problem went away.
Off-topic, but if these are like my old Response 3 speakers, you need to keep an eye on the screws/bolts that secure the woofers. Mine tended to unscrew themselves periodically, which resulted in loose, flabby bass. Keep 'em tight, but not TOO tight so as not to strip the threads. Good luck, Dave
A touch of Loctite Blue 242 will prevent the bolts from backing out due to vibration. Ask the manufacture for proper torque settings for the bolts.
Thanks for the responses, 'goners.

To answer your questions:
-Tpreaves, yes - it'd be an easy thing to try.

-Nicotico, I suppose you could call my room sparsely furnished, but it does have heavy drapes behind the listening position, a carpeted area, chairs, etc. I've had smaller speakers work better (i.e., other Proacs, Spendor, Sonus Faber) but not provide the low end I seek. The best shot was a system comprised of a Graff integrated driving Proac D25, supplemented with an REL Strata III sub.

-Dopogue, I always tighten up the drivers when I buy a pair of speakers, but have neglected to do it this time around. I'm on it!

-Brf, Great idea. I'm a cyclist and drummer and have used the blue Locktite for a number of uses. I'll try it on the driver bolts.

Thanks to all!

-Bob R
Have u tried pulling them out by another foot?...for a total of 3' from the wall. You should pick up a little more definition on the soundstage and the bass will diminish a little. Good luck.
They are already such a large speaker with spread-out drivers, I'd think that they're probably not designed to work in the nearfield. Bringing them out another foot would place them about 8-9' from the listener and 3' from the back wall. I suppose I can try it, but they'd certainly be intruding into the room.

Thanks for the helpful tip, Helosie!