Here are the Car Electronics questions on your ID:
6x9 Kappa question LINK
Prestige Alarm question LINK
Pioneer 920 Question LINK
Upgrade Recommendations LINK
AVIC-X920BT iPod question LINK
** = questions I have answered
So as you can see - I have not been involved in the selection process for your audio.
From what I have read - you have.... The AVIC-920BT and the 2 JBL amps in this question.
Reply to me exactly what is in your car - and what year Monte you have this in.
One of the most important specs you can look for in a speaker is it EFFICIENCY.
This is measured by dB (decibels)
The Higher the efficiency - the better the speaker will sound - as it takes LESS power for the speaker to produce the same output as a speaker with a lower efficiency.
To get the rating - they put 1 Watt to the speaker, and take an SPL measuremnt with the MIC at 1 Meter. You often see the spec listed as 98dB @ 1watt/1 meter. This is a baseline standard for comparison purposes.
some other things you may want to look for is built-in protection circuity or crossovers since you do not have any tuning components besides the settings on the amplifier.
Lastly - rear fill is just that - Rear Fill
. It is for the REAR seat passengers.
Your sound stage should be the dash. The music should sound like you are at a concert... with the band in front of you. It's why you often find competitors with NO rear speakers - and 3 sets in each door - or compression drivers (horns) under the dash.
Rear speakers are good in home theatres with surround sound - but not worth the extra investment. Get a "good" pair of coaxials - and perhaps spend the difference on an 11 or 31 band EQ to tune your system properly.
What is your budget for the 6x9s? And are you planning on purchasing Online - or in person?
I suggest visiting a few places to get a good idea of the difference in speakers. For instance - Alpine uses on-board capacitors and tend to have tinnier highs. JBL seems to be geared to be LOUD... and Infinity are inbetween. Nice overall - but low power handling.
BA would be my choice of the ones you listed.... based on SOUND alone. Not specs. Your ears and tastes may be different. The SC95 are 3-ways. They are ACTUALLY 2-ways with an extra tweeter. :)
Sensitivity is 92dB
60W RMS power handling
Based on SPECS ALONE - the JL would be the choice.