Difference in volume levels for surround speakers?

HTguru1982

Been playing around with the system today and decided to try three different pairs of speakers for my surround channels, RTi38s, RT7s and my current Monitor 4s. It seems that my Monitor 4's are the most efficient. I have to turn the speakers levels down to -4db to get them to blend well with my fronts.

With the RTi38s, it seems I have adjust the levels to 0db to get the same output. And with the RT7s, I have to adjust even further to +3db or +4db. The RT7s seem to work best overall but I'm confused as to why there's a 8db difference between them and the Monitor 4s.

I understand why there's a difference in volume between the Monitor 4s and RTi38s but the RT7s confuses me.

I have tried running the auto set up feature on my receiver and funny enough, it sets the surround channel levels to +4 regardless of which set of speakers is in place.

Sensitivity rating for each speaker according to Polk:
Monitor 4: 92db
RTi38: 89db
RT7: 89db

mantis

When you are tuning the system manually , I assume you are using a SPL? If so do you know how to use it? If all 3 speakers are playing the exact same SPL using the Auto mic and the db rating is the same for 2 and 3db louder on one , they should tune differently at least the Monitors should.
I'm wondering if your connecting the speakers out of phase.

HTguru1982

I'm doing it by ear but I probably will go buy an SPL meter just to be sure. I'll double check my connections to make sure nothing's out of phase.