# order of fir filter

Assume we want to filter the audio signal from a digital video disc (DVD) player as shown in Figure P5–3. The filtered audio signal drives, by way of a digital-to-analog (D/A) converter, a speaker. For the audio signal to have acceptable time synchronization with the video signal, video engineers have determined that the time delay of the filter must be no greater than $6 × 10^{−3}$ seconds. If the $f_s$ sample rate of the audio is 48 kHz, what is the maximum number of taps in the FIR filter that will satisfy the time delay restriction? (Assume a linear-phase FIR filter, and zero time delay through the D/A converter.)

• You posted a jpeg image of a multi-part IIR filter problem recently. The problem had a designator of 'Q3', a block diagram of an IIR filter, and mentioned the idea of "120 Hz flicker noise from fluorescent lights contaminating a photodiode signal." ROHAN, I need to find the source of that problem: Did it come from a textbook, college lecture notes, a web site, or just where? If you help me find the origin of that IIR filter problem I will reward you. Don't reply to me here on Sig. Proc. StackExchange, but rather, please send me an e-mail at R_dot_Lyons_@_ieee_dot_org. – Richard Lyons Dec 8 '16 at 9:44

$$\frac12 \times (577-1) = (6 \times 10^{-3}) \times 48000$$
• @robertbristow-johnson alright but $h[n]=\delta[n-9]$ is a single (nonzero) tap FIR filter with delay of 9 samples...? May be you're referrig to Type-I,II,III,IV even/odd symmetric causal linear phase FIR filters... – Fat32 Apr 6 '17 at 9:07