SPL CROSSOVER

The SPL crossover represents a high-end solution for precisely integrating bass speakers or subwoofers within an analog high-quality audio system, overcoming the limitations of common digital solutions that often require unwanted signal conversion. The crossover structure is divided into two distinct sections: one dedicated to low frequencies for bass speakers or subwoofers, available in both mono and stereo configurations, and the other for mid-high frequencies reserved for the main speakers. The crossover frequencies for the two sections can be independently adjusted between 50 and 120 Hz, selecting from six predefined positions, with a fixed 24 dB per octave slope for the low frequencies, while the slope for the mid-high section can be chosen between 12 and 24 dB per octave.

To ensure perfect time alignment between bass and main speakers, the crossover features variable phase control, which can be activated via a switch to select either 0° or -180° phase, finely adjustable to synchronize signals and maintain a smooth and coherent sound response. If phase control is not needed, it can be turned off to avoid interfering with the signal path. For users employing two separate bass speakers or subwoofers for left and right channels, the crossover is set to stereo mode, while if only one bass speaker is used, the mono mode is selected, which creates a unified signal sent simultaneously to both low-frequency outputs.

It is also possible to completely disable the mid-high filter to operate the main speakers in full-range mode, while the Low Cut filter removes all frequencies below 20 Hz, preventing the amplifier from delivering power to inaudible frequencies and thus relieving the speakers from unnecessary strain. The bass speaker or subwoofer volume can be adjusted from -10 dB to +10 dB, allowing correction of the system’s response or adding bass when recordings lack low-end. Two mechanical VU meters monitor input levels for the left and right channels, with a selector to optimize the display for different signal levels.

Input connections include both balanced XLR inputs and standard gold-plated RCA inputs, while outputs to power amplifiers or active speakers and bass/subwoofer units are made via balanced XLR outputs, ensuring a clean signal even over long cable runs, for example to mono power amplifiers placed near the speakers. The crossover includes a remotely controllable standby system via AMP CTL, allowing simultaneous on/off control of up to four devices, particularly useful for power amplifiers and for the crossover itself, which can be controlled by compatible preamplifiers such as the Director Mk2 or the Phonitor x.

From a technological perspective, the SPL crossover employs the revolutionary VOLTAiR technology, unique worldwide, operating at a DC voltage of 120 volts—four times higher than common operational amplifiers based on integrated circuits. This technology enables the use of specially designed operational amplifiers capable of handling ±60 V DC, known as SPL 120V SUPRA, which ensure exceptional technical specifications in terms of dynamics, signal-to-noise ratio, and headroom, alongside a sonic experience characterized by rich detail and extremely relaxed listening. The 120V refers to the device’s internal operating voltage, not the mains supply voltage, which is adapted by a toroidal transformer and a linear power supply with DC rectifiers. This high operating voltage allows the crossover to handle input levels up to +32.5 dBu, offering 12 dB more headroom compared to traditional devices working at ±15 V and supporting up to +21.5 dBu. This means all components operate continuously within an optimal range, reducing distortion and listening fatigue, delivering a natural, pleasant, and detailed sound that lets the listener fully enjoy every musical nuance.

Technical specifications:

• Analog inputs and outputs: XLR (balanced) and RCA;
• Maximum input and output gain: 32.5 dB;
• Input impedance (RCA): 20 kΩ; input impedance (XLR): 20 kΩ;
• Output impedance: 75 Ω;
• Common mode rejection (XLR): -82 dBu;
• Frequency response (-3 dB): 10 Hz – 100 kHz;
• Crosstalk (1 kHz): -70 dBu;
• THD (0 dBu, 1 kHz, MID-Hi filter on): 0.0008 %;
• THD (0 dBu, 30 Hz, LOW filter on): 0.0014 %;
• Noise (A-weighted, MID-HI output): -106 dBu; noise (A-weighted, LOW output): -104.9 dBu;
• Dynamic range (MID-HI output): 138 dB; dynamic range (LOW output): 136.9 dB;
• Internal linear power supply with shielded toroidal transformer;
• Operating voltage for analog audio: ±60 V; operating voltage for relays and LEDs: +12 V;
• Mains power supply: selectable 230 V AC / 50 Hz; 115 V AC / 60 Hz;
• Fuse for 230 V: T 0.5 A; fuse for 115 V: T 1 A;
• Maximum power consumption: 50 VA; standby power consumption: < 0.3 W;
• Dimensions (W x H x D, including feet): 278 x 100 x 300 mm;
• Unit weight: 5 kg.