Adding Height channels - questions on location and speaker size

Hi Guys, jumping in here...

I've just upgraded to a Onyo PR-SC5507 and am planning to add a set of speakers to go to 9.2. I'm currently running a 7.2 setup with Polk RT5000 (RT3000p mains, CS1000p center, FX1000 side surrounds and an extra pair of RT3000p upper satellites as rear surrounds.) I run a pair of SVS PB12/Plus-2's for subs. The 5507 does a nice job of room correction for both subs, BTW.

I'm considering adding a pair of Polk speakers for height, and have a choice to make. I already own and can use either a pair of Polk RT55i's, or a pair of Polk R1's. Here's my question, "How much frequency response does the height channel need?" I know more is better, but wider freq response means bigger speakers. The R1's are fairly small, and have a freq response from 65Hz to 20kHz with 5.25" driver. The RT55's are a lot larger, with a freq response of 35HZ to 25kHz. The R1's would be much easier to install, and if they have enough freq response to cover most of the audio signal sent to them, they'd be my choice.

I run a 7 x 200wpc amp for the existing speakers, but would probably use a smaller amp for the heights - somewhere around 75wpc. I could, however, run the heights on two of the 200wpc channels and use the smaller amp for rear surrounds. Obviously the larger speakers would benefit from more power, but again, if the signal is not there, why overkill?

Any advice?

Thanks guys. There doesn't seem to be a lot of info on actual users of the enhanced channels so your input is most welcome and helpful.

I've actually mounted one of the smaller speakers using a repurposed TV mount. I've ordered another just like it from Monoprice. They'll support 33lbs suposedly, so they should work for larger speakers if I go that way. The mount point is above and slightly wider than the mains, so I can check that box.

I've got plenty of sub capacity - a pair of SVS PB12-Plus/2's. I cross over the surrounds at 60Hz and the mains at 40Hz. I'll probably cross these at around 100-120Hz.

I still need to find a 2 channel amp to drive them, but it looks like 75 to 100WPC should be plenty.

I'll post with my results and share whatever I learn.

I do this because even at 80Hz, there is some directionality from the speakers. I prefer to hear the bass come from the channel intended, instead of from the subs. That's the whole point of the subs built in to the mains and center speakers.