Wow, thanks for the great info. Looks like both the Lanzar and JL amps are keepers. I never intended to replace them because they were top-of-line when I bought them and have served me well over the years and I'm glad to know they're still quality products even today.
I know people have said the Kenwood subs I bought were crap but at $47 per sub shipped, what is your opinion strictly on a value bang-for-buck basis? I'm not looking for cheap subs or high-end subs. . just subs good or better than the current C12A at the best value - did I get that with the Kenwoods?
Yes, both amps are keepers if they function 100%. You should know that there are some internal parts in amplifiers that can fail over time due to age. Capacitors can rupture and leak fluid. This is a problem with common in some amps 15+ years old. All I can say is try them, you have nothing to lose there. I am not saying this applies to ALL older amps, and the ones you have could very well last another 10 yrs.
The major advancements I have seen and heard are in
some of the full range class D mini amps from Alpine, JBL, Precision Power,JL Audio, etc. These amps ere exhibiting phenomenal clean output levels in a miniature chassis. Class G/H amps from Vibe Audio, Clarion, Arc Audio, etc. are beginning to gain reputation because they can produce Class A/B SQ at Class D efficiency levels. So, mainly the advancements are in the form of electrical efficiency by designing faster switching devices allowing a few Class D's to approach A/B SQ.
examples:
Class D:
WoofersEtc.com - P900.4 - Precision Power 4-Channel 900 Watt Max Class D Amplifier
11"x7"x2"
Precision Power PPI P1000.1 (p10001) Monoblock Phantom Car Amplifier
12"x7"x2"
Class G/H:
WoofersEtc.com - KS 300.2 - ARC Audio 2 Channel 700 Watt Amplifier
As far as the Kenwood subs, I would not have looked at them, but I do not know your budget and you already bought them, so you might as well try them....If you do not like them, my idea of best bang for the buck subs are the Powerbass M, L series, the Sundown E series, Sound Solutions Audio GCON series or the American Bass TNT. Any of these can be had for @ $125 ea or less in 10" or 12" versions. And there are several more to choose from too. IMO a good sub is one that will handle 150%+ of clean, unclipped rms input power on music.
The American Bass XFL 12" sub can handle 1500-2000w RMS for @ $200 ea. One of these has the potential to outperform any of the others I have mentioned in multiples, as far as SQL.
PASMAG | PERFORMANCE AUTO AND SOUND - American Bass XFL1244 Subwoofer
You mentioned the $1 per watt factor we all suffered from in the 90's and the cost of that JL 500/1...Check this out..A true 12v 500w rms @ 4ohm and 14v 2500 watt RMS @ 1ohm stable amp for less than $450. It requires pretty much the same electrical upgrades as one of those monster 1000w @ 1 ohm amps we remember from back when..
AQ2200D Amplifier