Admark AD60 or AD442 new Subwoofer AMPs for WSX

Isn't that longevity test indicative of how the amps with a claimed 5000w output only achieves 40hz sinewave output of less than 2750w @ 1% THD? The same test even down to 20hz with a Crest Audio Pro series amp would yield the claimed output at an astonishingly low 0.1% THD!

If that K30 was tested at 20hz with 0.1% THD  I wonder what the continuous output would be? By the same token, if the Crest amp was tested only to the same level that the K30 yielded its claimed output, I wonder what the output would be?

All Class D Professional Amplifiers designed these days (at the date of writing) are using the Crest Factor method as advertised ratings. If you look at the Measured Crest Factor chart, the K 30 offers the same output from 20 Hz - 100 Hz. So 4806.03 from 100 Hz - 20 Hz is 3398.89 watts continuous average at 4 ohms, @ 1% THD. That falls in line with Marketing which, will just state 5000 watts. So, the K 30 falls within its specifications. 

There is a misconception with low THD percentages. Any amplifier can achieve a low THD percentage providing you measure the amplifier multiple decibels away from clipping. Our industry (Sound Reinforcement) is about achieving a lot decibels without clipping the amplifier during process for, we know, a clipped amplifier is audible distortion. 

Bear in mind, the Longevity test offers a 0.96 dB differential when comparing 3398.89 watts and 2724.84 watts. No one in our industry is going to hear a difference from 3398.89 watts to 2724.84 watts. So it does not make sense the drive the amplifier into clipping and offer a deformed sinusoidal waveform. 

I am one of the few individuals in the sound reinforcement industry that measure amplifier output levels into frequencies ranging into single digits. Personally, my concern is what the amplifier can offer in terms of output from 20 Hz - 5 Hz if, I purchased it for Sub use. The only reason I used 40 Hertz, is due to the popularity of users on Speakerplans focusing on 40 Hertz. 

Best Regards,

Ok, thanks for the replies.

Back in the Good Ole Days, I did buy a few bits & pieces from Blue Aran. Good service & nice people, but then some Moron decided cut the UK from it's biggest market & make shipping, etc. a nightmare, never mind the extra taxes & pig-headed custom services here. One shipment (my last!) took nearly 4 months to clear here despite all the paperwork being fine. I think that were just pissed off over Gibraltar & took it out on me!!   

So, shopping in the UK a no go, I'm afraid...

And I guess yeah - given that the amps are all manufactured by the same 2/3/4 factories, then rebadged, I'll just do some Googling.