adulbrich 5,000+ posts
Olive oil un-virginer
People should be doing more R&D on this topic if they aren't already.There are two schools of thought about DF. One side thinks it's all important. The other thinks it's virtually useless and just a marketing thing.
The most simple way I can describe it is... it's essentially the internal resistance of the amp. And how much the amp "fights" the power returning from the sub. Higher DF = Lower resistance, less fighting. You'll hear people talk about "cone control".
The thing is... amplifiers have inherently low resistance anyway. AND the amp is just one of the components in the circuit that make up the system. The subwoofer coil being another HUGE component. Even if you had an amp with a DF of 1,000... by the time you wire it down to 1 ohm... that big ol' fancy impressive DF might be in the single digits on a Class D.
Better components have better tolerances and lower resistance. Same with build quality and the traces and all that little shit that goes into building a high quality amplifier. So higher quality amps just naturally have higher DF. They have higher DF *because* they're higher quality. They're not high quality because they have a higher DF. Does that make sense?
Have you ever heard Class A/B on subs? if you have, you know it "sounds" louder than comparable power of Class D. Or "cleaner" at least. Most will attribute this to DF. It's also the reason that wiring up to say... 2 ohms people get surprised how loud it still is even if they were running .5 before. Higher load, higher DF.
I can't go into detail about how DF specifically affects the TL score. or if A/B is actually louder than comparable Class D. But the anecdotal evidence is compelling. I reckon some (or a lot) of it may be the difference between high voltage and high current. But I have no concrete evidence one way or the other.
Thank you very much for the information!
