Check the listing for details. F125 Professional Speaker Crossover Filters 2 Way Auditory Frequency Dividers. Condition: New. Listed at 47.90 USD. Specifications: Item: F125 Speaker Auditory Frequency Divider. This effectively extends the life of the entire auditory. Features: Double bass special two-crossover crossover: crossover refers to the different frequency bands of the sound signal to distinguish, respectively, to the amplification, and then sent to the corresponding frequency band of the speakers and then playback.