Everyone is giving you good advice, but no one is giving you a systematic solution.
First -
What are the models and brands of all your speakers. With that we can look up the specs and find out what the Sensitivity is. That is the place to start because we may find that Sensitivity is not really the issue.
Second-
Give us a budget and any other limitations you might have, like space limitations. Can we assume your rear satellites are small bookshelf speakers?
With the Sensitivity of your current speakers and a budget for your new speakers, we can probably find a solution.
But, before you go that far, consider this, maybe it is not your speakers but your amp configuration. I'm certainly not knowledgeable in Surround Sound, but I'm under the impression that most Surround Sound amps have several 'play' modes. That is, difference setting to tailor the sound to different needs and preferences. Have you tried these other 'play' modes to see if there is one you like better?
I'm also aware that some Surround Sound amps can calibrate themselves by connecting a microphone and playing some test material. Can you, have you, calibrated your amp?
Also, it could be something as simple as the rear speakers being wired backwards. That could cause weak sound do to phase shift. Check you wiring and make sure it is correct. Yes, I know that's painfully obvious and simple, but even the very best of us still make mistakes.
So, let's start with what you have, then gradually work our way toward what you might need.
Steve/BlueWizard