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How to Choose a right Audio Capacitor for Your Crossover Application? 

1. Nominal parameter

The nominal parameters are the values listed on the capacitor casing.

*Electrostatic capacity, expressed in UF.

*The working voltage, abbreviated as WV, should be the nominal safe value, which means that in the application circuit, it should not exceed this nominal voltage.

*The common temperatures are mostly 85 degrees and 105 degrees. In general, selecting a high temperature coefficient also has a positive impact on improving the performance of other parameters.

2. Dissipation factor (DF)

Sometimes the DF value is also represented by the loss angle tan. Whether the DF value is high or low is related to temperature, capacity, voltage, and frequency; When the capacity is the same, the higher the withstand voltage, the lower the DF value. The higher the frequency, the higher the DF value, and the higher the temperature, the higher the DF value.

The DF value is generally not marked on the capacitor. When selecting capacitors for DIY, priority can be given to selecting higher voltage withstanding ones. For example, when the working voltage is 45V, choosing 50V is not very reasonable. Although using 50V is not inappropriate in terms of normal operation under voltage, there is a lack of consideration in terms of DF value. Using 63V or 71V withstand voltage will have better performance.

3. Equivalent series resistance ESR

The level of ESR is related to the capacity, voltage, frequency, and temperature of the capacitor, and the lower the ESR requirement, the better.

When the rated voltage is fixed, the larger the capacity, the lower the ESR. When the capacity is fixed, selecting varieties with high rated voltage can reduce ESR. At low frequencies, ESR is high, at high frequencies, ESR is low, and high temperatures can also cause ESR to rise.

4. Leakage current

Of course, the smaller the leakage current, the better!

The higher the capacitor capacity, the greater the leakage current; Reducing the working voltage can reduce the leakage current. Conversely, choosing higher voltage resistant varieties will also help reduce leakage current.

5. Ripple current Irac

Ripple current is a very important parameter for the filtering circuit of stone machines. The higher the ripple current Irac, the better. Its height is related to the working frequency, with Irac increasing at higher frequencies and Irac decreasing at lower frequencies.

The traditional view is that we need to have a high ripple current at low frequencies in order to achieve good high current discharge characteristics, make the low frequencies more robust, full, elastic, and have good control and driving characteristics.

In fact, the high ripple current at high frequencies also greatly contributes to the positive sound quality, allowing for better extension and reduced roughness at high frequencies.