Polk Audio RTiA9's vs. LSiM707's

How are your speakers placed, do you have a pic of your setup?

You need to know what it is that you think is lacking in the way music sounds in your room. I don't think that getting those Polk LSiM 707's will do anything but make your wallet a lot lighter. I have a feeling this is a room problem or a calibration set up problem. I fought a similar situation with my system. It wasn't any of my gear that was the problem. It was partly a calibration problem and a speaker placement problem. My mains needed adjustment. The distance from the wall needed to be increased as well as toe in and aligning the tweeter and mid with the listing position and ear level. I made some tilting adjustable platforms to do this. My mains are really tall. Now music and movies sound great.

If I could go from A9's or even my LSi15's to the 707's I would do it. But not at that cost. I haven't listened to the 707's but I can't imagine them sounding THAT much better.
Of course if you have money to burn...............

Can you post a photo of your setup? The tweeters should be a ear level. You've got a tough setup there.

After hearing this it's not the speakers that is your problem it's the set up. The speakers are to close to the wall or in the wall and to high. I had similar problems with lack of mid bass and certain frequencies when my mains where to close to the wall and not sticking out further than my subwoofers. This causes imaging and reflection issues reducing or canceling certain frequencies. You won't eq them back and you shouldn't try anyway. I now use zero eq correction. The sound before the changes and how it is now is a drastic difference. I have great mid bass and clarity and great imaging.

That's a 48 5/8" tall speaker sitting an extra 30" high? So 78 5/8" minus about 6 5/8" gives you a tweeter height of 6'.... Unless you're an NBA player sitting on a bar stool, your ears are no where near 6' when sitting in front of the speakers. That is definitely your problem. You need to be at or near ear level with the tweeters to hear any high frequencies, and even worse with an MTM section controlling the vertical directivety you are getting limited mid frequencies as well.

These speakers are meant to have there backs against a wall, but not recessed into one.