It’s also a chameleon, the same ease with which it reveals changes in its own state of tune effortlessly exposing shortcomings in system setup and partnering equipment. The contrasting virtues of different front-ends, their behavior under warm up, and the importance of carefully considered support have all rarely been clearer. A speaker like this attracts audiophiles like bees round a honey pot. I’ve been beating them off with a stick, but none of those who have slipped under the guard have gone away anything other than bowled over: Something else this Grande shares with the Isis—the ability to readjust a listener’s notions of what is possible. Seldom has a speaker looked so striking and sounded so unlike it looks.
For many (most?), the cost of the Grandes and the space required to accommodate them will mean they remain a pipe-dream, but their tonal, spatial and temporal coherence, their extended bandwidth, and their truly astonishing dynamic capabilities (at both ends of the spectrum) put them in a very select category indeed. They rub shoulders with the Isis—and probably Wilson’s X2, although that’s one speaker that I haven’t had at home. This select group really are do-it-all speakers, whose weaknesses and shortcomings have more to do with practicality and matching than gross failings in performance. Indeed, they do less damage to the signal than a lot of matching electronics.
From a company’s point of view there are many different reasons to build a flagship speaker, from attention seeking to trickle down. But confronted by a $180,000 product, reviewers and potential purchasers need ask only one question: Does this speaker go straight to the top of my “if I won the lottery” list? Well, as far as I’m concerned the Grand Utopia EM is firmly ensconced atop that pile, waiting to be shot at. Bring on the competition.
With the Grande Utopia EM, Focal has made a serious statement of intent, one that challenges the boundaries of speaker performance. That makes it worthy of more attention than we can give it here, and attention from more than one reviewer too.
This is one that will run and run, in the sense of other views and also other products, as much for what they say about the Grande as vice versa.
The “EM” in the Grande Utopia EM’s name stands for “electromagnetic,” the drive principle employed in the woofer. Before looking at how this works, let’s review the operating principle of a conventional moving-coil driver.
The power amplifier drives alternating current (the audio signal) through the voice coil, generating a varying magnetic field around the coil that is an analog of the audio signal. The varying magnetic field changes its north-south orientation at the audio signal frequency because the audio signal is alternating current—the current flow reverses direction at the frequency of the audio signal. Send 1000Hz to the driver and the current flow through the voice coil reverses direction 1000 times per second. This reversing magnetic field created by current flow through the voice coil alternately pushes and pulls against the fixed magnetic field generated by the driver’s permanent magnet, causing the voice coil to be pulled back and forth, and with it, the cone.
This approach, used in virtually all modern moving-coil loudspeaker drivers, runs up against the laws of physics. Specifically, the magnetic field strength generated by the fixed magnets is limited, which in turn places restrictions on the cone weight, how low in frequency the driver will play, and how sensitive the driver is. A heavy cone goes lower in frequency (all other factors being equal), but requires greater magnetic-field strength surrounding the voice coil to drive it.
Focal’s solution to this physics problem is to replace the driver’s fixed magnets with a large coil that functions as an electromagnet. The coil is driven with direct current from an outboard power supply that plugs into an AC outlet. This current flow through the coil creates the magnetic field against which the voice-coil–generated magnetic field pushes and pulls. The electro-magnet produces a magnetic field strength in the gap (the area in which the voice coil sits) nearly double that of a conventionally driven woofer. Consequently, the EM’s woofer can be heavier (giving it a lower resonant frequency) yet simultaneously more efficient. Moreover, the woofer’s bass output can be adjusted by varying the current through the electromagnetic coil. This is accomplished in the EM via a rotary switch on the outboard supply that drives current through the electromagnetic coil. One can thus adjust the EM’s bass output to better integrate the system into a variety of listening rooms.