Speaker questions

Greetings,

Just put in the second of the two way speakers in the back doors. Here's the config:

Replaced stock rear "speakers" with Clif Designs QX6550 2 way speakers. Had to build a custom mount to attach to the door, used 7/16" HDPE board (very acoustically dead, even more so than MDF.) Applied Damplifier padding to inside of door, on outer (inside) panel all over, and on inner parts within 6" of the speaker. Painted the corners inside and the exposed metal on the inner frame with 2 coats of Spectrum, as well as painting two coats on the backside of the plastic door panels. Now there's a huge difference if one raps with knuckles on the front door vs. back door. Finally, a single layer of overkill foam right behind where the speakers will sit. I'm happy with the acoustic damping.

I have the base non-JBL system. Here's what I found after this partial install:

The rear speakers were pretty quiet relative to the stock "speakers". I bought the Clif Designs speakers because they were priced competetively (as Clif designs was bought out in the late 90's, people are trying to get rid of existing stock,) and because they were rated at 95 dB sensitivity (1W/1m.) This compares favorably with offerings from a/d/s (Precision Power now,) Infinity, and JL Audio. In theory, this efficiency should allow me to get more volume from less amplifier. However, once volume levels were comparable, the rear speakers sound much more musical, with better balance, timber, and much better attack on both bass notes, and the high end. (For the time, cost and effort, they damn well better sound superior to the stock "speakers.")

But it sounds like I'll have to run the stereo at about 50 to get decent volume levels off of my iPod or a CD. Since it only goes up to 64, I'm worried about clipping and artifacts.

I have a pair of Clif Designs QC6500C component speakers to put in the front slots (woofers and tweeters.)
That's the next install. The other nice thing about these is that the woofers are rated down to 30 Hz. Not sure if that's a proper +/- 3dB rating, but if they do go that low, might not need a subwoofer.

Now, my question. For those of you with the base non-JBL stereo, when you replaced your speakers, how did the volume compare? Are the Infinities comparably loud to the stock speakers? Are the 95 dB sensitivity of my speakers pure BS, or have I perhaps done something wrong, or understood something incorrectly. I know the stock head unit amplifier has very little power, but was hopeful that the high sensitivity would help. Are Clif Designs notorious for bad ratings? Or is this typical?

If this is what I've got, and nothing is wrong, the next step (after the front speakers are in,) will probably be to put in an amp. A decent Alpine with 40 W/channel can be had on eBay for $120 or so, and the JL Audio 70W/channel for $250. Anyone have experience with these? I'm looking for really clean sound, not really loud. No need to share my music at stoplights, but want as close as I can get to my home system (Creek CD or iPod, B&K preamp and dual mono amp, Legacy Focus speakers.)

Any advice appreciated. Thanks in advance.

Regards,
Martin