The other big change in bass implementation is the move to a flow-port arrangement, which feeds the output of the downward-facing port through a wide, forward-facing slot between the bottom of the cabinet and the plinth. This improves the port’s interface with the room and also keeps it more consistent when it comes to boundary conditions.
Like everything else in loudspeaker design, making the most of the advances made with the bass unit was a question of balance, weighing up how much of the benefit to spend on overall system sensitivity, how much on adjustability. Setting the range of adjustment at ±3dB allows an overall system sensitivity of 94dB. As well as significant level-compensation at low frequencies, this allows the elimination of subtractive components in the mid and treble crossovers, components that limit transparency and dynamic response.
But Focal wanted to further increase user optimization, and settled on a set of high-quality jumpers to give three-step settings that enable users to tweak crossover slopes between mid and treble, as well as tweeter and midbass levels and sub-bass Q. Add in the level control on the bass PSU and that’s 1458 permutations. Thankfully, the discrete and repeatable nature of each step makes the process simple to execute and easy to navigate. The upper range adjustments give a tilt and “smoothness” function to compensate for the liveliness or balance of the room, but it’s the ability to balance midbass and sub-bass levels against low-bass Q that is critical to achieving the scale, presence, and coherent dynamic range of which the Grande is capable, and which represents one of the key breakthrough developments.
However, one unforeseen effect of the elimination of subtractive elements as well as the increase in bass transparency and lower levels of low-frequency distortion was increased audibility of crossover component quality, necessitating in turn, a complete overhaul of crossover components (including the development of dedicated designs) and the selection (by blind listening) of new internal wiring. Only with these developments in place was it possible to fully realize the potential of all the other advances, finally delivering the kind of step-change in low-frequency performance that characterized the impact of the beryllium tweeter on the upper reaches of the second-generation Utopia Bes.
Installing any speaker that weighs 572 pounds is always going to be an issue, but the Grandes proved easier than most. The fact that the top cabinet element is removable helps reduce the weight a little and the height to manageable proportions, while the integral casters allow you to roll the speakers straight out of its crate and into place—as well as helping with fine-tuning once they’re up and running and before installation of the (necessarily) substantial spikes. Once the speakers are in situ, the top box needs to be lifted into place (a two-person job) and the power supplies connected. Then, you can finally start thinking about all those adjustments. I opted to position the speakers for optimum performance with the controls set flat before any further refinement, finally settling on a combination of 1.5dB mid and sub-bass cut with a notch increase in Q.
Two other points need to be made about the feeding of the Grandes: Despite a 94dB sensitivity, small amps are out; and it matters how you feed the power supplies. On the latter point, don’t skimp on the AC power cords—you will hear the difference. And on the former, even the impressively linear, tactile, and well-controlled 20W output of the Vacuum State monoblocks didn’t do justice to this speaker’s frequency extremes. Around ten times that is a more sensible target, with the Levinson 383 and both the Ayre and Berning monoblocks all putting in sterling service. Power and
load tolerance is definitely the order of the day.