Hi ! i have the question in the title
I would like to understand if it is possible to simulate with LTSpice how changes the response to an impulse in various points of a RLC passive network
Like a speaker crossover network for instance
Of course i would love to be able to check this on a scope But at present i am fighting with space
By the way i am working to find a space where to set up a little lab My life's dream
Thank you to Anyone
Have a nice day
gino
I would like to understand if it is possible to simulate with LTSpice how changes the response to an impulse in various points of a RLC passive network
Like a speaker crossover network for instance
Of course i would love to be able to check this on a scope But at present i am fighting with space
By the way i am working to find a space where to set up a little lab My life's dream
Thank you to Anyone
Have a nice day
gino
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If you run a large-signal simulation (.tran), ALL voltages and currents are available at ALL points and through ALL components.
It is then up to you to probe or measure them.
If you use an impulse as source, you can probe voltage/current shapes at all points and parts.
Gino, have you abandoned the other project?
Jan
It is then up to you to probe or measure them.
If you use an impulse as source, you can probe voltage/current shapes at all points and parts.
Gino, have you abandoned the other project?
Jan
Thank you very much indeed On the basis of my experience the key is to find the correct set of settings to run the sim
If not the results are not usable
I have the feeling that LTSpice is not very popular among speaker crossover designers I asked because sometimes i see some review with this kind of test
I want to check if an inductor is the worst offender for a response to an impulse and in particular what changes with the inductor place in front of a driver or after the driver It is a my curiosity Maybe nothing will change
unfortunately yes I am facing my basic ignorance
I hoped that using a sim would have been an easier way to understand parts and circuits behaviour
Sadly sometimes sim provides not realistic results and i do not even understand this
Ignorance at the max level
I understand i should start from some school book I will see what young students use in the first electronic schools
My dream would be to see a simple circuit with few parts and understand if it can work or not
Imho You designers are geniuses indeed Sometimes i see circuits so complex that my head spins
However if the theory is beyond my limits i will try with basic measurements
I will buy soon a cheap but possibly cheap signal generator and use my sound card for some measurements as a start
If you have any suggestion for something cheap but still decent ... signal generator i mean
Thank you sincerely for your extremely kind and valuable support
Have a nice day
gino
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You need to set the simulation up as a time-domain one. Which is a '.tran' or transient one. If you're getting a frequency response perhaps you have it set to '.ac' ?
10mS should be sufficient time to see a crossover's impulse response.
Gino, I did give you clear instructions to sim the current source.
Please forgive me, I do not intend to insult you, but by jumping from one project that you don't understand to another that you don't understand, you are just working to keep your ignorance.
There are masses of people trying to help you here, but you need to want to be helped.
Ignorance can be fixed, stupidity not. You clearly are not stupid, so fix it! With help of your friends.
Jan
What is 1 and 2? Where are they connected to? Where is the signal source connected to?
Consider that and you have your answer.
Jan
the signal source is a impulse generator
case 1 is woofer followed by a coil to ground
case 2 is a coil placed before the woofer
The basic question is what kind of impact has an inductor on a impulse ?
or considering a square wave again does an inductor warp a square wave ?
my guess is that it does and usually it is found where it does more harm i.e. in series to a woofer
I read that an inductance by its nature opposes the variation of current that passes through it
This is a very bad thing for a woofer to the point that some are looking for woofers that can work without a filter like full-range ones.
However, there is at least one brand that places the inductance after the woofer (the direction is from + to -)
Everyone says it's ******** That nothing changes before or after the woofer I can't accept it I'm talking about the positive half-wave which in the end is what really matters
case 1 is woofer followed by a coil to ground
case 2 is a coil placed before the woofer
The basic question is what kind of impact has an inductor on a impulse ?
or considering a square wave again does an inductor warp a square wave ?
my guess is that it does and usually it is found where it does more harm i.e. in series to a woofer
I read that an inductance by its nature opposes the variation of current that passes through it
This is a very bad thing for a woofer to the point that some are looking for woofers that can work without a filter like full-range ones.
However, there is at least one brand that places the inductance after the woofer (the direction is from + to -)
Everyone says it's ******** That nothing changes before or after the woofer I can't accept it I'm talking about the positive half-wave which in the end is what really matters
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There should be no difference in the impulse responses of the woofer followed by a coil or the woofer preceded by a coil. The acoustical frequency responses of the woofer for these two cases are identical.
Of course, in this situation, the coil must "warp" the square wave, as it adds what is essentially a low-pass filter response into the system. It doesn't matter where the coil is located (preceding or following the woofer).
Using a full-range driver is fraught with many difficulties. There are going to be many structural resonances in the loudspeaker driver radiating surface (be it a cone, dome, or planar radiator). These are very difficult to control and lend their own sonic signature to what we hear. Having inductors and capacitors in crossover circuits helps a well-designed multi-way loudspeaker system to avoid many sound quality degradations due to driver break-up modes.
Of course, in this situation, the coil must "warp" the square wave, as it adds what is essentially a low-pass filter response into the system. It doesn't matter where the coil is located (preceding or following the woofer).
Using a full-range driver is fraught with many difficulties. There are going to be many structural resonances in the loudspeaker driver radiating surface (be it a cone, dome, or planar radiator). These are very difficult to control and lend their own sonic signature to what we hear. Having inductors and capacitors in crossover circuits helps a well-designed multi-way loudspeaker system to avoid many sound quality degradations due to driver break-up modes.
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hi thank you very much indeed for your kind and valuable advice You mean that a signal will look the same after passing a wire or an inductor ?
In the case of the inductor before the woofer the woofer will see a signal as you say warped and its response will be influenced by the warping
I should really need to see on a scope or at least at simulation I cannot figure that out
I understand very well A driver good for low Hz must be physically different to a driver good for high Hz ... it is physics
Even panels come with different sizes They have big membranes for basses and smaller membranes for highs
To be honest lately i have seen a big interest for speaker solutions where the mids and highs are reproduced by a same wideband driver placed above a bigger bass boxes that provide a full range response I think that the concept can work nicely and required only a 2 ways crossover
I would always keep the bass in another cabinet The woofers are like wild beasts They need a separate "cage"
There has been a famous guy saying "Unless I see ... I will not believe it."
Below are the two circuit conditions modelled in VituixCAD.
In the plot below, the frequency response (black line) is the summation of drivers D1 and D2, which are pure 8-ohm resistive loads and each of them has a simulated flat response between 5 Hz and 40 kHz. The D1 and D2 responses are identical, and the summed response is the expected 6.0 dB greater than that of either driver alone.
In the plot below, the frequency response (black line) is the summation of drivers D1 and D2, which are pure 8-ohm resistive loads and each of them has a simulated flat response between 5 Hz and 40 kHz. The D1 and D2 responses are identical, and the summed response is the expected 6.0 dB greater than that of either driver alone.
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Hi thank you so much for your very kind support But i am more worried about response to impulse and/or square wave
I follow a basic reasoning
The inductor by its nature opposes to the change of current flowing through it ... we agree on this ? (by a twist of fate, inductors are found precisely where they are most annoying in series with the woofers)
So if we send an impulse what arrives at the + of the woofer cannot be the same if the test signal has passed an inductor or a simple wire because they are not the same thing T
he woofer will see a different signal in the two cases and it will respond differently to a different signal
The difference is to be seen Maybe the more the mH the more the effect ... i do not know
I believe a lot in test using impulses like impulse step and square wave to get info on the dynamic behaviour of the driver
See this difference for instance (unfortunately capacitor response is missing but for sure it will be much better than an inductor)
the resistor gives back a very good SW so it is not critical
Again there must be difference in the rise time if the woofer is fed through an inductor or a straight wire
We can say that an inductor will slow down the signal ?
An inductor placed instead between the - of the woofer and ground could even be good to shorten the settling time of the driver (damping)
If i had a human situation at home i would try immediately with some rock or disco track, a track with PRAT i mean (i.e. with Pace, Rhythm Attack and Timing)
I follow a basic reasoning
The inductor by its nature opposes to the change of current flowing through it ... we agree on this ? (by a twist of fate, inductors are found precisely where they are most annoying in series with the woofers)
So if we send an impulse what arrives at the + of the woofer cannot be the same if the test signal has passed an inductor or a simple wire because they are not the same thing T
he woofer will see a different signal in the two cases and it will respond differently to a different signal
The difference is to be seen Maybe the more the mH the more the effect ... i do not know
I believe a lot in test using impulses like impulse step and square wave to get info on the dynamic behaviour of the driver
See this difference for instance (unfortunately capacitor response is missing but for sure it will be much better than an inductor)
the resistor gives back a very good SW so it is not critical
Again there must be difference in the rise time if the woofer is fed through an inductor or a straight wire
We can say that an inductor will slow down the signal ?
An inductor placed instead between the - of the woofer and ground could even be good to shorten the settling time of the driver (damping)
If i had a human situation at home i would try immediately with some rock or disco track, a track with PRAT i mean (i.e. with Pace, Rhythm Attack and Timing)
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It will likely be helpful if you look up Kirchhoff’s Current Law. The two different circuit layouts all result in the same current flowing through each section of the circuit. If the same current is flowing, then the voltages across the two loudspeakers will also be identical, as V = I x Z, irrespective of whether or not the inductor precedes the loudspeaker.
Witwald is absolutely right, but maybe it helps when looking from a different angle.
The voltage source sees a speaker and inductance impedance, so a current I will flow.
Let the speaker and the inductance change positions.
The overall impedance will still be the same, so the same current I will flow as before.
A voicecoil in a speaker will react to a current according to F=BIL where F is the force on voice coil, B is the strength of the magnetic field, I is the current from the voltage source and L is the length of the voice coil winding.
Do you see a voltage in F=BIL, no there is not.
So, since the current is the same regardless of inductance before or after the speaker, the speaker will react exactly the same in both cases.
Hans
The voltage source sees a speaker and inductance impedance, so a current I will flow.
Let the speaker and the inductance change positions.
The overall impedance will still be the same, so the same current I will flow as before.
A voicecoil in a speaker will react to a current according to F=BIL where F is the force on voice coil, B is the strength of the magnetic field, I is the current from the voltage source and L is the length of the voice coil winding.
Do you see a voltage in F=BIL, no there is not.
So, since the current is the same regardless of inductance before or after the speaker, the speaker will react exactly the same in both cases.
Hans
Let me try to understand There is a Vac generator (the amp) and the load (the woofer)
When the signal is positive (half wave above 0) it pushes the woofer cone out
when it is negative (half wave below 0) it pulls the cone inside ?
when the signal is positive the flow is from + to -
when it is negative the flow is to - to + ?
i would like then to ask ProAc why they used to wire their crossover differently Just to be original ? i mean for no particular technical reason ?
If anyone would do the same ok But ProAc made me thinking
When the signal is positive (half wave above 0) it pushes the woofer cone out
when it is negative (half wave below 0) it pulls the cone inside ?
when the signal is positive the flow is from + to -
when it is negative the flow is to - to + ?
i would like then to ask ProAc why they used to wire their crossover differently Just to be original ? i mean for no particular technical reason ?
If anyone would do the same ok But ProAc made me thinking
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i do not understand well If i place a 1.5V battery across the + and - of a woofer the cone moves back or forth in relation to polarity
But again i would need to see and hear I will try to make a test asap is just a matter of swap terminals on a biwirable speaker I should have one
I will connect the red of the tweeter with the black of the woofer and send the red of the amp to the black of the woofer
Hearing is believing
But again i would need to see and hear I will try to make a test asap is just a matter of swap terminals on a biwirable speaker I should have one
I will connect the red of the tweeter with the black of the woofer and send the red of the amp to the black of the woofer
Hearing is believing