I don't know where ICG ever got the idea that anybody does not use inductor resistance in their simulations. He said that about my X-Sim pic, maybe because it is not displayed on the schematic.
X-sim inserts a default resistance for all inductors, as I believe all software does, and the difference between default and actual (when plugged in) is so small it is insignificant.
This guy is very difficult to communicate with because he makes a lot of assumptions without foundation, and is also very insistent about his knowledge of physics.
The problem is, most of the details he talks about are the tiny ones that rarely make an audible difference, and with my current set of resources I'm looking at the bigger, more general picture. the minutia have to wait.
But apparently this is, to some, simply the WRONG way to design speakers.
Pfft.
The actual (real live) driver response will cancel that claim. And the modification of just +2Hz (!!!!!) fb will defeat it completely! It does not even alter that curve to 0.1dB!
In the thin material is where you sacrifice the stiffness on which you've layed emphasis. I don't see how putting the resonances into a frequency range where the ear is a lot more sensitive is of any help. What you are describing is not a speaker, it is an instrument with properties to make noises (which do not belong to the music it aims to reproduce). It's always better to avoid resonances instead of provoking them!
Aside from that, you've already claimed ply would need less braces. Now you tell us it needs more. Which one is it then? I've got the impression you do not know very well what you are talking about and just turn arguments around once you've got the impression that would help you more.
What you're doing is putting up frets on a guitar and let the enclosure play its own tunes. And you will help the OP to 'tune' his speaker on every side and panel? Please, I'd like to learn, tell me on which principle the braces have to be placed and how you calculate it.
You've got a strange misconception about wood materials. Plywood does not have a good absorption/inner damping properties and making it thinner makes it even worse. The higher stiffness of ply comes from the long wood fibres and that's why it doesn't absorb (damping) vibrations well. Use a contact microphone and you'll see the plywood is a hell lot noisier than MDF.
I'm sorry but I don't see any advantage in having a lot more work, more audible noises AND having to pay a lot more for the material.
15mm quality ply is stiffer than 18mm MDF. I use an appropriate amount of thickness for the box. If we err in any direction it is overbuilding.
dave
dave
Yes, it is. And we already etablished that it's not an important acoustical positive property.
Well, that's nice, what is an appropriate amount of thickness then? But more importantly, where to put and how many braces? 'Appropriate' is such a stretch.. 🙄
I overbuild pretty much everything. There is no reason not to keep the cabinet out of the driver's passband.
Later,
Wolf
Later,
Wolf
Which one is it then?
It is not a binary choice. It is system design.
If a panel is stiffer, the span can be longer to achieve the same panel resonance frequency, as the shorter less stiff panel.
The boxes we build are expressly tested for whether music can excite the panels. And refined over at least a couple decades.
The key is get the potential resonant frequency up high enuff so that music is very likely if ever to excite that resonance.
Theoretically one could take it to the next level by tuning the resonances so that they do not fall on any notes of the well-tempered scale. In practice it is not required.
MDF’s mass and lack of stiffness makes it harder to push the box resonance up elegantly.
Making incorrect assumptions does not help your case. The plies are what bring the stiffness, and the transition from 1 ply to the next isa damping region.
Now the damping will have a different FR than taht of MDF.
But if one can get potential resonances up high enuff that they are never excited, then there is nothing to damp.
dave
Thank you, if you've got no arguments, correcting an grammatical error was a very important contribution to the thread then. I hope you will allow to excuse my mistake since I'm not a native speaker.