Upgrate Polk RTI8 with Lsi9 crossover & tweeter


Wondering if anyone had any opinions of whether or not modifying my Polk RTI8 speakers with the crossovers and ring tweeters with those of Polk LSI 9 would work. I am not be hacking a pair of LSI'9s but have extra parts already. The 8's tweeters are kind of cheapo overly brite at times for music listening using 2 Audiosource Amp 3 amps (2 channel 150 RMS wats @ 8ohms with Harman Karden 645 AVR) The LSI 9's are awesome speakers with my gear but are 4 ohms and would like to turn the 8's into something close if possible but are 8ohm speakers. Crazy idea or what.
greenbudster
If you use the Lsi9 tweeter and crossover, Bi-Amp with 2 Audiosource Amp 3 for high and Low, Adjust the volume control on the amp3 to balance sound, I believe it will work, Is it sound better? I can't tell you. One problem: is the tweeter fit in the cutout?
IME of designing, modifying and buiding speakers (often with Polk's) it will be a bit of a crapshoot.

The challenges include but are not limited to:

If the drivers have different sensitivities, which is likely, the LSI9 x-over will yield a non linear frequency responce.

If the drivers are different impedances then the LSI9 x-over points will shift as well as change the higher slope to a lower 6db slope, leaving a gap between bass and tweeter output.

IMO, you are better off installing the better tweeter and then upgrading the existing RTI8 x-over with better parts as well as changing the tweeter part of the x-over to accomadate the new tweeter.

It may be fairly easy as the two tweeters (RTI8/LSI9) may be the same impedance and sensitivity. In that case you would simply have to upgrade the parts in the existing x-over.

At the very least you would need a Digital Multimeter, a SPL meter, and a CD test disc with 1/3 octave test tones on it.