Originally Posted by diy speaker guy
Thank you for this.
In this case the primary motivation was simply to model this driver to see what it takes to extract it's full potential within the rated power handling spec. It takes a very low tuning to do this. Like I said, I'm not married to the 2 hz idea and probably won't build this anyway but I'm still interested in the concept. And the concept is sound, as I've shown here. I'm satisfied with that and I don't really care that I haven't convinced anyone. It wasn't hard to do though, since the only arguement put forth is that all the software is all wrong.
The point of this concept was to use only the top half of the port resonance, the other half (the problematic half) was ALWAYS supposed to be buried in signal chain rolloff ON PURPOSE. This idea was not ever about playing 2 hz tones at full volume, or ever even "hearing" 2 hz at all. It's not meant to be providing effective output until around 5 hz or higher, where there is actually some content in some material. The concept uses a very small port but buries the consequences of such so low that it doesn't matter. It won't chuff because it won't ever see the frequencies that might cause chuffing.
So I'll leave you guys (and this topic) alone now. Thanks anyway.
I didn't say anything about the software being wrong. Software crunches math based on the user's input. My point was as basic as it gets; the input is where the flaw resides.
You posted a sim, then you posted another sim. The 2 sims were radically different, but no matter because, although you mention signal chain roll off in passing, as though it's an irrelevant piece of data (as most do), it actually is the whole bowl of wax.
Taking loopback measurements of the analog SW output of a popular AVR, a popular PEQ and a popular amplifier, summing the additive effect and applying that signal chain data to your sims shows a far more accurate picture:
This is a typical result using popular signal chain hardware. It can easily be far worse depending on the hardware in the chain, but it can also be far better. In fact, more attention to the signal chain can improve performance below 10 Hz magnitudes greater than building a huge box and sticking a long pipe in it.
What I'm saying is that you either raise the tune to see a real advantage before the signal chain roll off (as the seasoned vets of that sort of alignment have repeatedly said in this thread) or focus more effort improving your signal chain fidelity. Both avenues will yield far better results than discussing a grossly flawed computer simulation.
Also, I mentioned it in my post that incorrect edicts about content should be a thing of the ancient past, but still persist and cause a huge and unnecessary waste of virtual ink. You appeared to agree, but have posted that 'no content ever contains...', etc... Of course, that's just not true:
This is one of many examples that have been around for quite a few years. I'm mentioning it here because it's pertinent info and no one should be misled by posts to the contrary. IF anyone decides to get serious about signal chain fidelity, thinking this content doesn't exist will end in destroyed hardware.