Bandwidth

Bandwidth is defined as a frequency span- the difference between a high frequency and a lower frequency.In sound, the word can be utilized in different ways, depending on context. As a simple example, an equalizer with cutoff frequencies (the filter's 3 dB point) of 200 Hz and 2000 Hz has a bandwidth of 1800 Hz. The audio bandwidth is generally defined as 20 Hz to 20,000 Hz, although there are harmonics that can extend far beyond 20 kHz. In situations where bandwidth is given as an audio specification, i.e. in frequency-response charts, the wider the bandwidth, the better.In audio electronics, we can compute the "Q", or Quality Factor for a filter using the bandwidth; the quality factor is defined to be the ratio of the center frequency Ä divided by the bandwidth.

Band limiting Filter And Band pass Filter

Band limiting Filter

A low-pass and a high-pass filter in series, acting together to limit the overall bandwidth of a circuit system to a certain parameter of frequencies. Also band-pass filter. The low and high frequencies between which the filter allows signal to pass are usually determined by the filter's -3dB points.So-called because it limits a signal to a specific frequency range.

Band-pass Filter

A low-pass and a high-pass filter in series, acting together to limit the overall bandwidth of a circuit system to a certain parameter of frequencies. Also band-limiting filter. The low and high frequencies between which the filter allows signal to pass are usually determined by the filter's -3dB points.So-called because it limits a signal to a specific frequency range.

Balanced / Unbalanced

An audio wiring scheme referring to an electrical (audio) signal having two "legs" independent of ground. One leg is generally considered positive (+) with reference to ground, and the other negative (-). A third conductor, the shield, is an outer wrap of conductive metal encircling the two inner, signal-carrying conductors. In balanced wiring, when the signal reaches the destination, the negative copy of the audio signal is polarity-reversed and added to the positive signal. Any noise induced into the signal on its travels is also reversed; when combined with the non-reversed noise, the two noise signals cancel each other out. This phenomenon is called "Common Mode Rejection." Balanced lines are thus used for lengthy cable runs in which unbalanced wiring schemes would be susceptible to induced inteference. The shield functions as a true shield, sending any waste-material noise to ground.Unbalanced lines have only a positive (+) signal, and the negative signal is carried on the shield of the cable. Any noise induced into the cable will make its way into the audio signal.Another use of a balanced wiring scheme is coming into popularity: balanced power systems. The concept remains the same- instead of an AC scheme wherein there is a positive signal which carries 120V with respect to ground (US), a neutral which carries 0V with respect to ground (ideally), and a ground, the positive and neutral legs both carry inverted copies of 60V with respect to ground. In this case, again, the power supplies can cancel any noise induced into the AC line and produce cleaner audio. Theoretically.