No (we talked about this before 🙂 )
There is definitely a difference.
The issue is the resonance, which is either directly introduced, or introduced by lower harmonics (because of the non linearities of the motor).
What makes me wonder is what a active notch will do with a series RLC parallel to the woofer.
The rlc will give a shorting path for the back emf. Unfortunately we have to be careful for not overloading the amplifier as well as dissipating to much power.
At the same time, the active notch takes care of the resonance.
Also, I assume that the amount of attenuation is determined by the shunt impedance as well as the speaker impedance at that specific frequency?
Like A=Zshunt / (Zshunt + Zspeaker)
Just a brainstorm what that would bring.
The rlc will give a shorting path for the back emf. Unfortunately we have to be careful for not overloading the amplifier as well as dissipating to much power.
At the same time, the active notch takes care of the resonance.
Also, I assume that the amount of attenuation is determined by the shunt impedance as well as the speaker impedance at that specific frequency?
Like A=Zshunt / (Zshunt + Zspeaker)
Just a brainstorm what that would bring.
Like this. Excuse the lame grafics of the circuit:
R12, L12 and C12 in series, Z shunt. And Z shunt in parallell with speaker. Zspeaker II Zshunt are yellow. Blue is Z speaker
R12, L12 and C12 in series, Z shunt. And Z shunt in parallell with speaker. Zspeaker II Zshunt are yellow. Blue is Z speaker
Frequency response is of course the same. With or without shunt. But I really don't know what would happen with distortion at 5k, Or will that be 1,7k
The hysteresus type distortion I was describing was unrelated to any cone resonance. It is a broad band distortion in the region above fundamental resonance.
Yes, you can see this as a sort of steady level. Similar to like background noise.
No that's not what I meant. 🙂
We can just have series RLC straight to ground, no series resistor needed.
Remember; just to give a termination path for the back EMF to be shunted.
C = 10, L = 0.1, R = 0.1 (R part of L)
Well don't think I would chose such a risky solution. Smell burnt amp here.
Thinking of it all, I doubt it is possible to electrically sink a mechanical distortion that is already existent in the driver. That is for speaker
V is unchanged
I is unchanged
Source impedance is unchanged if Zout amp is < 0.1 ohm
But I have been wrong before.
Well don't think I would chose such a risky solution. Smell burnt amp here.
Thinking of it all, I doubt it is possible to electrically sink a mechanical distortion that is already existent in the driver. That is for speaker
V is unchanged
I is unchanged
Source impedance is unchanged if Zout amp is < 0.1 ohm
But I have been wrong before.
That's why I said that the R can't be to low to prevent overloading the amplifier as well as dissipating to much power in that resistor 😉
So no, you're not wrong 🙂
Ah, you were refering to the R201 resistor. Sorry forgot to mention it is a 0 ohm resistor in this simulation
We are miscommunicating to the max at the point, haha 😀
The lowest impedance is determined by R2.
Sorry that was a drawing mistake on my end.
Obviously a RLC notch is with a C as well 🙂
OK, then my two first simulations should be valid.
Both R1 = 4
Simulation 1: L1 = 1 mH, C1 = 1uF, Narrow Z total dip
Simulation 2: L1 = 0.1 mH, C1 = 10uF, Broader Z total dip
Both R1 = 4
Simulation 1: L1 = 1 mH, C1 = 1uF, Narrow Z total dip
Simulation 2: L1 = 0.1 mH, C1 = 10uF, Broader Z total dip
Right, which is not a very nice value, unless you want to dissipate a lot of power.
Practically speaking, you have to go to about 10-16 ohm.
So it's interesting to see how well (and if even) this combination works.
Like I said, it was just a braintstorm, see where it brings us.
Although we need measurements at this point.
As a side note se http://www.troelsgravesen.dk/Illuminator-71.htm uses RLC like that to linearize speaker impedans at upper end. So if the designer need linearized impedanse at HF part of speaker that could do the trick with the right values. That apply also to active system, but often it is not a requirement bacause of amps with low source impedance