Grimani Systems loudspeakers are active speakers, and make use of digital signal processing (DSP). All the amplifiers and DSP are located in the speaker to increase reliability and simplify installation. Our speakers accept a standard AES/EBU digital signal at 24bit, 96kHz resolution that is carried on a standard CAT 5 cable. Having high quality and very powerful digital signal processing for each loudspeaker enables us to take a slightly different approach loudspeaker design.
Of course, the most obvious thing to do with DSP in your speaker is to use it for the crossover. While ANY form of active crossover is vastly superior to passive crossovers (ones that use large capacitors, inductors and resistors), a digital crossover is more flexible, has less noise and distortion, and is more stable over time than any analog crossover could ever be. Traditional passive crossovers, frankly, have no place in a premium cinema system loudspeaker. They introduce distortion components. They are a potential failure point. They can’t be built with nearly as much precision. High order slopes are simply not practical to build…and that’s not the worst of it.
Passive crossovers make the electrical load that the amplifier “sees” much more complex and difficult to drive. They also keep the amplifier from being able to directly control the motion of the drivers (woofer, midrange and tweeter). Whatever damping factor your amplifier has, if it’s driving a speaker with a passive crossover, just forget it! (Damping factor is the ability of an amplifier to control a driver’s motion.) The resistance in a typical passive crossover will GREATLY reduce that number. This increases “ringing” or “time smearing” in the driver as they can’t be adequately controlled. But it gets worse, still.
Perhaps the most insidious problem passive crossovers have is one that few people consider. A passive network must be tuned to the impedance of the drive unit it is connected to. As the voice coils in the driver heats up the resistance of the wire changes. This means that the tuning of crossover changes! This is a bigger problem in cinema sound as higher sound pressure levels are required, and thus, the voice coil must dissipate more amplifier power.
This effect can be substantial. Crossover points start drifting around creating misalignments. This will be a random effect that changes with listening level and program content. It usually manifests as an unintended peak in the frequency response in the area of the intended crossover – frequently in the 2.5kHz to 3kHz region.
Ever wonder why many speakers start to sound harsh when you crank ‘em up. Wonder no more. The solution: Good quality signal processing set up by someone who really understands how to use it.
Of course, the other big things we do with DSP are to time-align the drivers with delay, and apply frequency equalization. Good designers of more conventional loudspeaker systems must be concerned with an array driver parameters and strike a compromise between them. For instance, expensive audiophile grade drivers can have very low distortion and very good frequency response, but very typically have low efficiency and power handling capabilities. When the requirement for high SPL that cinema environments need comes along, those good qualities are sacrificed for the ability to play loudly and not get damaged. How does Grimani Systems solve the problem?
Because we have such powerful DSP build into our speaker, we can optimize our drivers for low distortion, high efficiency and power handling, and not concern ourselves so much with box tuning and frequency response. We have all the signal processing we need to linearize the drivers’ response while keeping the size of the cabinet down. Ultra low distortion, ultra linear frequency response, high efficiency and high power handling give Grimani Systems loudspeakers unrivaled clarity and naturalness of sound with all the dynamic punch you could ask for.