Focal
Grande Utopia EM
  • IAL 2
  • W
  • OPC+
  • Focus Time
  • Specifications

Force factor : +83%

The force of a driver is its magnet and the magnetic energy transmitted. A subject Focal knows well for having invented original and technically advanced solutions such as the Multiferrite magnet that was and still is one of the technological signatures of the brand.

But the permanent magnet is limited in power and in the framework of a reference woofer, it’s a real problem. Because a woofer should at least combine two essential performances: high efficiency and ability to go down in the low frequencies.

To go down in frequencies, we can adjust the surround and the spider flexibility, but we should above all increase the cone weight. If we increase the cone weight, the efficiency drops. And to compensate this drop, we have to Increase the magnet power. That’s where the limits of the permanent magnet step in, forcing a compromise between efficiency and resonance frequency.

Only solution for Focal, reconsidering the very existence of the permanent magnet...

We adopted an Electro-Magnet for our new 16” (40cm) woofer. Thanks to the simulation software and to the existing materials, this extreme solution goes back to the very origins of the driver and was optimized to supply the expected force (patent pending). The magnetic field in the air gap reaches 1.75 Tesla (0.9 for the woofer of the previous Grande Utopia Be that was yet equipped with a Multiferrite magnet) to supply a force factor (the real power of the motor) of 34T.m.

The goal is reached: the efficiency for 1W @ 1m reaches97dB, whereas the resonance frequency drops to less than 24Hz.

  

Here lies the true performance.

The EM Electro-Magnet is made of a 15.4lb (7kg) copper coil. The motor including the coil weighs 48.5lb (22kg). The 16” reaches a total weight of 52.9lb (24kg). “A monster” in the literal meaning of the word, where manufacturing costs cannot be compared to a standard magnet and are only onceivable on exceptional loudspeakers.