Looking at their stock listings of PPI amps at acaraudio.com (anybody used them?) I noticed that for the new PPI amps, you don't get much of an RMS increase when going from 4 to 2 ohms.
For instance, the old PCX-440 • 40W x 4 at 4 Ohms • 100W x 4 at 2 Ohms
And the new DCX300.4 • 50W x 4 at 4 Ohms • 75W x 4 at 2 Ohms
So basically RMS *quadruples* on the old PCX but increases only by 50% on the new DCX when you move from 4 to 2 ohms.
Why is that? What does that suggest about the technology in the new DCX models? Is an amp that has a bigger jump in RMS likely to run warmer? Do most amps have a big jump like the PCX or a slighter one like the DCX?
"Why is that? What does that suggest about the technology in the new DCX models? Is an amp that has a bigger jump in RMS likely to run warmer? Do most amps have a big jump like the PCX or a slighter one like the DCX?"
It means that the DCX amps aren't built as well as the older ones for one. It's that simple, really. The ideal amp would double its power with half the impedance, which is rarely the case.
thanks Jonathan, that's the first answer I've managed to get for this question.
How realistic do you think most amps' power ratings are? In home audio it's known that with a couple of exceptions most receivers costing under say $1000 have inflated RMS numbers.
I'm just wondering since you wrote that the ideal amp would double RMS with half the impedance, while the PCX440 claims to quadruple RMS. Is that in your opinion likely just marketing guff or is there some chance that it's an honest claim?
That theory holds true sadly lol. 400W Cerwin Vega E-715's, almost $400 each...V-15F's are smaller in cabinet size, so they can only charge like $320 lol.
