Crossover
Description:
This function creates digital crossovers for active multi-way loudspeakers.
Options:
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)
Use:
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.