Polk RTI Setup Questions

[Armzzzz]

Hi guys,

Love the forum. Have been reading posts like a fat kid eats in a candy store.

Just bought a new set of speakers for a large basement room:
RTI10 fronts
RTIA3 rear
CSIA6 Centre
Sub Velodyne CBT-15 (powered 300 watts rms, already had this, love it haha)

Running it off my crappy very old HTIB Pioneer receiver that does 20 watts rms per channel so time to upgrade.

My question is, what would the optimal set up be xover and power wise? (Which in turn would lead me to the proper avr/amp choice.)

This is what i'm thinking optimal wise:
Sub crossed over at 80hz, power RTI10's with a dedicated amp to let the two 7" woofers handle the bulk of 80-125hz.

Or do the 7" woofers in the rti's stand no chance vs the 15" sub even at the higher frequencies so i may as well just get a decent AVR, set the 15" inch xover at 100hz and whatever the AVR gives the RTI10 7" inchers for 100-125 will be good enough with the slope overlap?

I suppose the dedicated amp is optimal, but in the real world i'm guessing it might not be worth the money and added complication given the beefy powered sub. I'm basically a n00b though and taking wild guesses so i don't know haha

Thanks for the help!

 

[j_garcia]

I don't know anything about that sub, but since it is self powered, it will handle the low bass better than your towers whether you have an amp or not. 100Hz would be too high for any of your speakers. 80Hz should be a good starting point, but I think you will want to start with a pretty decent level receiver for the RTiA-10s, or as you said, get an amp for them. The problem is, if you get an amp and use a lower end receiver, the mains will sound great and the center may suffer without similar power.

 

[Armzzzz]

Wow, never considered the centre not being balanced. Good point.
I'm leaning towards getting a solid receiver for the sake of simplicity regardless. Unless i'm mistaken I think the 7"ers in the polks are internally crossed 125Hz and below. Thats too high?

 

[j_garcia]

There is no RTiA-10, only a -9, so it is either an A-9 or a RTi-10. Either way, they play down to around 30Hz, so you would want to cross them about 1 octave above that point or 60Hz. If the receiver you get doesn't allow you to set the crossover by speaker location (front, center, surround, etc...) then you would go with a global setting of 80Hz for the benefit of the other speakers. Setting the mains to 60Hz also means they will demand a lot more power from your receiver also though.

Even for the RTi-A3 (which I reviewed last year) would not benefit from a 100Hz x-over because it will tend to make you loose some of the lower midbass - plus they can play low enough to work with an 80Hz x-over so you don't want to "waste" a portion of the range that all of these speakers are capable of handling just fine. 60Hz would be too low for the center and surrounds though, and that would create a gap between them and the sub when they roll off before the sub starts to pick up.

 

[Armzzzz]

Ahhhh I misinterpreted what you meant. Thanks for clearing it up. Just for reference, its the RTI10s. I think the powered sub handling the bulk of 80hz and below and a solid receiver juicing the RTI10's (and the rest of the gang) somewhere between 60-80HZ and up it'll be more than adequate. Maybe playing with an amp and gains etc would maximize the potential of the rti10's but i'm thinking real world listening won't be drastically different given the beefy sub and non optimal ears listening to it all

 

[j_garcia]

The sub's x-over should be set as high as it goes; that way the receiver handles the x-over and you don't double up your roll-off.