For those who haven't seen it elsewhere... I tested a couple amps last week.
I'm not going to repost the whole spiel about how it went down, but the resistive part is on fixed resistance (like the AD-1 amp dyno) and the other is a traditional clamp at .25 nominal (except the Crown) on a pair of Tantric HDD15's.
Family photo. the B2 and big bish all the way to the right are just for funsies. They were tested, but won't be included in this one.
NS-1 next to the CT.
CT Sounds 7k - 7,000w resistive - 7,930w rising to .9 - 71% efficient - 158.6db
American Bass 750.1 - 6,200w resistive - 7,100w rising to .9 - 72% efficient - 158.2db.
Sundown NS-1 - 5,800w resistive - 6,550w rising to .9 - 72% efficient - .7db down from the CT.
DD M4a - 6,000w resistive - 6,490w rising to .9 - 71% efficient - 158.0db
JBL Crown 6000 - 5,200w @ 5 ohm resistive - 6,400w rising to 3 ohms - 62% efficient - 158.2db
Popcorn Sounds 6k - 5,100w resistive - 5,700w rising to .9 - 60% efficient - 157.1db. Dirty, dirty as ****.
Not surprisingly, the amp that made the most power was the loudest. What is surprising (to some) is the amp that's 4th out of 5 in terms of apparent power was tied for 2nd in score. There's something to be said for A/B topology there. Even though I think it's some sort of hybrid.
Dollar per watt/score... I'll have to begrudgingly give the nod to the Popcorn. Even though I don't know how much they are. Assuming they're $800 or so? That's 14 cents a watt. Which is 3 cents cheaper than the CT. But I'd trust the CT waaaaaaaaay more than a Popcorn. The other (3) come in at ~ 22-23 cents per watt. Still a bargain for the quality of amp you're getting, IMO.
CT Sounds - solid performer. Made the same power at 10.5 dcv as it did ~ 14v. This is great news for battery guys. That puts it in DD territory as far as low voltage beastliness. It's also a big bish if you're into that kinda thing. The white is clean but makes scuffs, scratches, smudges stick out like a **** on a fish. The pots on this amp were the "cheapest" of the bunch. I don't care for the plastic Phillips head pots. It's not a deal breaker. Just an observation. bass knob/Voltmeter also earns bonus points from me. It has a clipping indicator on it too, but it's not of much use. It started flickering around 40acv when it made over double that clean. No surprise there since I've been telling y'all forever that those things are just a light show.
Side note on the CT: it's the only amp here with triple inputs. Ryan only had (2) spare leads so we tested it first with just duals. But we agreed to test all the amps the way they were designed. Fwiw... The 3rd input was worth .2 on the meter.
AB 750.1. I've got love for the VFL's. What I don't care for is AB's ratings of them. They've seemingly gone to "max" power ratings. The amps are solid enough. They don't need inflated rating to sell them. Do they? Bonus points for the AB being 18v stable. It would walk these others once you get past the 16v CT and 15.2v DD. But... That doesn't help the 12v guys. It's also a big *** amp physically. It dwarfs the M4a in size, but not so much in score. Still way up there on my recommend list even though I feel like it underperformed here. Most efficient of the bunch by what probably amounts to margin of error.
M4a... Oh how I love thee. Smallest amp in the bunch and perhaps a bit of an underdog in this one. It fell short of DD's 7k rating, but still made the most power per sq in of real estate. Low voltage monster. Bulletproof as they come. Doesn't like .25 much so it took a slower roll to get it there but it did fine. We tested the protection circuit pretty good finding the sweet spot on the roll. .35 is the lowest I'd recommend burping this one. Has the lowest operating voltage of all these amps. 15.2-15.3 or so is all you're likely to be able to run. Not a concern for 99% of people but its nice to have a little cushion in the voltage.
JBL Crown... This is one of those holy grail type amps. Its hyooooj. Entirely impractical. Not so efficient and 1,000% awesome. Do want. This test absolutely demolishes the efficiency myths floating around about this amp. It's really a gigantic, retardedly bad *** SQ amp. It's also a 2 channel so it was bridged here. It ALSO only has single inputs. And I'm now cursing the fact that we didn't test it with duals. Just might have caught that big white bish. This amp is just plain *** and the output test was just for funsies but it impressed me even though I've heard it before. This amp will be mine. Oh yes... It will be mine.
Popcorn Sounds... GFY.
Sunown NS-1 - Most expensive amp in the test. More optimized for high voltage operation so it was maybe at a disadvantage in this one. Still did well at 14v, but this one and the AB would really start stretching the others out with more voltage if that's your thing. This amp is basically an M4a that is operational to 19v. Which is awesome considering how much I like the M4a.