This function creates digital crossovers for active multi-way loudspeakers.
1. Input fields for crossover frequencies of the individual drivers, together with desired delays of each driver relative to the lowest frequency driver. If a driver is required to be moved earlier to match the lowest frequency driver, the “delay” may be negative.
2. There are several types of crossovers available:
- Butterworth / Linkwitz find their counterparts with analog filters, although unlike their analog counterparts may be made linear phase.
- Neville Thiele: Provides a steep separation with a slightly sloping top, whereby undesired frequencies are very well suppressed.
- Bessel: These filters have the shortest ringing, which allows the step response to be highly optimized.
A companion function recently introduced allows the creation of Horbach-Keele crossovers (speakers must be designed with this crossover in mind, or at least fit its requirements by lucky accident) which provide nearly constant vertical dispersion of sound over a broad range of frequencies.
3. Selection of linear or minimum phase
4. Filter length (Higher values result in longer, more accurate filtering with longer latency and higher CPU utilization. Recommendation: 44.1kHz-48kHz: 65536 taps, 88.2-96kHz: 131072 taps, 176.4-192kHz: 262144, 352.8 - 384kHz: 524288 - note that very long filter lengths with multiple crossover frequencies can put extreme demands on the convolution computer.)
DelAIlXO: If checked, deletes all linear phase crossover files in the active directory before creating the crossovers to be generated. Does not delete minimum phase crossovers - probably a bug.
5. Crossover Format (Only if the convolution software used cannot handle .dbl filters, or the .wav files that Acourate can create from them choose single precision .pcm)
Digital crossovers can be superior replacements for analog “hardware” crossovers in active multi-way speakers. They can also be linearized and fully adjusted for time accuracy. Impulse and step response for speakers using such crossovers can approach theoretical limits.