Enter your Center Frequency (f0), Q Factor, Gain, Filter Type, and Sample Rate into the Equalizer Frequency Calculator to find your filter's Bandwidth, Bandwidth in Octaves, Lower and Upper -3dB Frequencies, and Angular Frequency — everything you need to dial in a precise EQ band.
Bandwidth
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Bandwidth (Octaves)
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Lower -3dB Frequency
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Upper -3dB Frequency
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Angular Frequency
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Q factor (quality factor) determines the bandwidth of an EQ filter. Higher Q values create narrower, more precise frequency adjustments, while lower Q values affect a broader range of frequencies. Q is calculated as center frequency divided by bandwidth.
Bandwidth is calculated using the formula BW = f0 / Q, where f0 is the center frequency and Q is the quality factor. The bandwidth represents the frequency range between the -3dB points of the filter response.
Peaking filters boost or cut frequencies around a center point while allowing all frequencies to pass through. Bandpass filters only allow frequencies within a specific range to pass, blocking frequencies outside that range.
Sample rate determines the maximum frequency that can be processed (Nyquist frequency = sample rate / 2). Higher sample rates allow for more precise filter calculations at high frequencies and reduce digital artifacts.
Bandwidth in octaves (N) is approximately equal to 1.44/Q for narrow-band filters. This relationship helps audio engineers translate between different measurement systems when designing EQ curves.
For musical applications, Q values between 0.5-2.0 sound natural. Higher Q values (3-10+) are useful for surgical cuts or correcting specific resonances. Lower Q values (0.3-0.7) work well for gentle tonal shaping.
The -3dB cutoff frequencies are the points where the filter response drops to half power (70.7% of the peak level). These frequencies define the effective bandwidth of the filter and are used to calculate Q factor.