KEF XQ40 Review Bismarck ND
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KEF XQ40 Review
By Geoffrey Morrison
The most common type of speaker design has a tweeter towards the top of the speaker and a woofer below it. Some speakers mix it up with a woofer above too, or maybe a mid-range in there somewhere.
The XQ40 from KEF, like most of their speakers, does something a little different. The tweeter is inside the woofer.
Called a concentric tweeter, there are acoustic benefits and of course, potential negatives. KEF calls the design " Uni-Q " (say it out loud, it's kinda clever), and claims it "disperses an accurate sound image evenly throughout the room." In other words, because the sound waves are emanating from the tweeter and the mid-range from the same "point" in space, the sound gets to your ear "time aligned."
This means the sound is theoretically more accurate, and has the potential to have better frequency response off-axis. The potential downside is a shouty, horn like sound. Have a friend cup their hands over their mouth and say something, and you'll get the idea.
But those are just the potentials. Let's take a look at the acutals.
The tweeter in question is a 0.75-inch aluminum dome, residing in the center of a 6.5-inch mid-range where you'd normally find a dust cap. The tweeter crosses over to the midrange at 2.5 kHz. Bass comes from two more 6.5 inch woofers that come into play below 400 Hz. KEF claims a sensitivity of 90 dB with 2.83 volts at 1 meter. The XQ40s can bi-wire/bi-amped.
The curvy cabinet design is solidly built. My review samples had the Birdseye Maple finish, which I found quite attractive.
To start I hooked my laptop up to the Simaudio Moon i3.3 and went through my music library on random, to get a feel for the sound of the XQ40s. One character readily came across: a razor sharp center image. Vocal tracks benefitted from this the most, with a rock solid image between the speakers.
This isn't to say there was no stereo imaging, which there was. On one end of the spectrum you have speakers like electrostats that can create a diffuse sound, but often at the expense of accurate imaging. Think of the XQ40s as the opposite of that. Not a judgment call either way, both have their proponents and fans.
Moving away from the center, there wasn't the usual drop-off found with many other speakers. So if you have a wide room or a lot of seats, the XQ40s would be a good choice to ensure those seated at the edges of your theater still get decent sound.
KEF claims the XQ40s are 3 dB down at 45 Hz, and that wouldn’t surprise me. Depending on your room and usage, if you don’t want a sub you certainly don’t need it. The XQ40s go deep, but it's not overwhelming or out of balance with the rest of the sound.
While I love the sound of the i3.3, I like to try different amps with each set of speakers I review. Not every amp sounds good with every speaker, and vice versa. I swapped in a Sunfire Cinema Seven, a 400 watt per...