You have several options in upgrading.
- You could add 2 surf speakers to your tower array and go into the hybrid setup which gives amazing sound quality and also great projection with the summing of all the enclosures.
- You could Add another XM7 into the mix and call it a day.
- You could go 2 pair XM9. And have a lot of output for your rider up there on the tower.
I would not suggest mixing 7's and 9's. It looks goofy on the 1 to 1 relationship, and also doesn't allow for proper crossover point tuning.
Check out our face book page for more examples of all this. A lot of XM9's are getting posted up there...
And if you want a hand in walking you through some of your options, give us a call at the office (800) 249-0970 and we can go over the details, find a dealer for you, etc.