If you find room modes are troublesome, you may want to add a couple subwoofers. This may seem counterintuitive, especially if you feel that the bass is strong. But what will happen is bass will be made more smooth as a result. Use CARA and figure out where to place the subs. I have found many cases where the four opposing corners are best, and others where they're not. Of course, your decor will determine what you have to work with too.

I usually suggest the additional woofers be the same as the ones in your sevens. They don't have to be cornerhorns, but they surely can be. If not cornerhorns (with mids and tweeters), then low-pass them very low, below 100Hz. This prevents localization and improves integration, by keeping sound sources acoustically close. Or you can go with a different approach, using woofers like the LAB12 that are tuned for a very deep range. This lets you hit even deeper bass notes while providing smoothing of the overlapping range. You may be able to install subs in cabinets that fit under existing furniture. You can usually find a configuration that models well in CARA and that also fits in nicely with your room decor.