What does a Zobel filter do?
A Zobel network is used to flatten a driver’s impedance (usually a woofer or mid-range), therefore making the filter (usually low-pass) more effective. Their values are chosen to minimize the impedance rise of a driver above the resonant frequency.
How is Zobel calculated?
Impedance equalization circuit / Zobel network calculator
- R = 1.25 * R. e
- C = Le / R.
- Re is the DC resistance of the speaker.
- Le is the inductance of the voice coil of the speaker.
- R and C are the values of the resistor and capacitor for the impedance equalization circuit.
Is Zobel network necessary?
Zobel network is needed to correct some instabilities of the amplifier, because of (imprevisible) phase variations caused by wires or/and crossovers, drivers, etc. Problems are occuring at high fréquencies (10 Mhz or so…), and cause some sound harshness. This can vary from case to case, from time to time.
What is Thiele network?
The Thiele Network Inductors have a low impedance to low frequency current and a high impedance to high frequency current. Audio signals are relatively low frequency, so they will flow through the inductor uninhibited.
How does a Zobel network work?
A Zobel network is a series resistor-capacitor (Req-Ceq) network that is connected in parallel with a loudspeaker driver in order to neutralize the effects of the driver’s voice coil inductance Le (see note below about Le).
What is a Zobel crossover?
A Zobel can be used to restore the impedance of the driver to the nominal value in the high frequency range. This will allow the crossover filter to operate more effectively in the high frequency range where it is used to attenuate the highs going to the woofer.
What is Gainclone amplifier?
Gainclone or chipamp is a type of audio amplifier made by do-it-yourselfers, or individuals interested in DIY audio. It is a design based on high-power integrated circuits, particularly the National Semiconductor Overture series. As an amplifier it is highly regarded by many in the DIY community.
What is meant by image impedance?
Image impedance is a concept used in electronic network design and analysis and most especially in filter design. The term image impedance applies to the impedance seen looking into a port of a network. Usually a two-port network is implied but the concept can be extended to networks with more than two ports.
What kind of filter is the Zobel network?
For the wave filter invented by Zobel and sometimes named after him see m-derived filters. Zobel networks are a type of filter section based on the image-impedance design principle.
How can I design a Zobel network for my woofer?
You can design a Zobel network for your woofer by starting with a resistor (at least 10 Watt) equal to the nominal impedance of the driver. For an 8 Ohm woofer you would use an 8 Ohm resistor, 4 Ohm woofer, 4 Ohm resistor, and so on.
When to use a speaker Zobel circuit calculator?
Speaker Zobel / Impedance Equalization Network Circuit Calculator. An Impedance Equalization Circuit, also know as a Zobel circuit, can be used to counteract the rising impedance of a voice coil caused by inductive reactance.
Why is it important to use a Zobel capacitor?
The importance to use impedance compensation should be clear now… C z is the calculated Zobel capacitor [uF]. Adding a Zobel to a woofer will allow the passive crossover to work more effectively. The impedance of the woofer will also be restored to the driver’s nominal impedance throughout the high frequency range.