I run AB amps, which can considered on-par with Crown. They were technically sold as "PA" or "band" amplifiers, but in all reality they are just big brutes.
My AB 9620b is a daily listener and the poor thing rarely goes beyond 5-10 wpc output to keep neighbors happy, but once a home is procured it'll get it's legs stretched a bit.
Anyhow, there are some things you'll want to consider with these types of amplifiers.
1. They NEED a legit preamp. The output from a typical PC won't cut it. I went through this with mine, and even though it has several line level presets, it would never make rated wattage from just the PC. What's odd though is I tested several car amplifiers in-house and set their gain as low as it'd go, and the pre-out from the PC had them doing rated wattage. Usually band amps have mixers, etc. So if you want to actually hit the rated wattage figures, get a preamp. If one of your existing amps has in/out jumpers, you can use that as a preamp, but you'll be adding adding wear and tear to it.
2. These amps use XLR connectors almost exclusively. I bought some XLR ends at Radioshack (when they still had them in their bins) and cut the ends off some higher end RCA cables and soldered them into the XLR ends. You can buy actual adapters, but they cost more. I've had no issues with this.
3. If you try bridging one or running 2 ohm stereo on 120v, you'd better have your electrician come out and update the breaker, and possibly run a 200 amp box if you only have a 100 amp box now. My amp, if pushed at it's limit, can pull something like 32 amps and would be like running 2 blow driers at once. Not to mention I have a preamp, EQ, PC, TV, etc. all on at same time, so plan accordingly.
4. 600 wpc powering modest 91 SPL full-range speakers (or better) would be extremely uncomfortable for casual listening unless you have a movie theater-sized listening room and are throwing a party. If you are only going to use the amp for subs, and you are running a pair of DVC subs with an 85 SPL, you probably still won't be pushing them at their limit as you won't hear vocals, etc. You could always try running some type of active bass boost crossover and run the amp 16 ohm and still have enough bass to rival most cars with subs, especially if you use walls to deflect the bass back as it can actually increase db. There's a name for the effect, but I don't know what it's called. If you like really tight kick-drum bass, put subs about an 1" from a walled surface or put a 3/4" pressboard in front of the box, and listen to the difference.
5. If you have say a 3 way design with 5 speakers per cab in stereo, it'll soak up some of the wattage, but you'll probably find 16 ohm @ 300 wpc will be just as effective as 600 wpc @ 8 ohm, and the amp will be using LESS power from the wall at 16 ohm vs. 8ohm. The lower the impedance, the hotter it'll run and the more power it'll need.
6. Car amp makers have brainwashed so many people with false advertising it's not even funny. (not saying you are) By this, I mean they plaster stupid high wattage values on their amps and even their speakers, and people think their 1800w amp is legitimately powering their speaker. In most cases, it's not and probably lucky to be 200w. To put things into perspective, back in the early 90's when car audio was getting big, you could have 150 wpc amp @ 4 ohm powering a pair of 95 SPL single voice coil subs with small magnets and running an inline bass boost crossover, and people could hear you over a block a way. Run four 10" 95 SPL at 150 watts each, and you could be heard a couple blocks away and rattle peoples windows as you passed by in the street. Nowadays, DVC subs are like 84 SPL and they actually need crazy wattage just to get as loud as the smaller systems from 25 years ago. Why? Because there's more money spent on big wattage numbers and they've painted themselves into corners with ridiculous claims over the years. Point I'm trying to make is, if you specifically hand-pick high SPL speakers for cabs (I consider 92 SPL or better to be high), you can have 150 wpc classic SS class A/B amp and be plenty loud. Ignore the speaker SPL and get 85 SPL, and it'll need a bunch more power.
