In this two part article by industry veteran Pat Brown from Synaudcon, we get a full explanation on the benefits and limitations of FIR filters for speaker design.
- Part one of the article goes through the basics of FIR. A very good summary of how/why/when to use FIR filters.
- In Part two, Pat makes use of rephase along with REW study to showcase a real life scenario.
Figure 1 – At the top we see a 60 tap FIR HPF. Note the lack of sharpness due to the small tap size.
Next, adding more taps (more samples or a longer time length) creates a sharper filter, and then at the bottom,
we have a 6000 tap filter that is 136 ms in time duration, with latency of 1/2 of the length (68 ms)
Figure 2 – The polar response at 1 kHz (1/3-oct, 5-degree angular resolution)
using the LR24 crossover (A) and the linear phase brickwall crossover (B)
A must read for all speaker designers out there thinking about using FIR and wanting to learn more.
For more info on Synaudcon and their great learning/training sessions, make sure to check out SynaudCon website.