Dbx 234xl Crossover - Usually 3-5 Days. 45 Day Lowest Price - 100% Satisfaction Guarantee. At first glance you'll notice this unit is great looking, and as you turn the controls something else becomes apparent; these units are extremely well built. The controls exude great precision, and the feel is a solid click. All dbx crossovers feature Linkwitz-Riley 24dB per octave filters.