QSC KSub Powered Subwoofer

You probably figured from my last review that I am pretty happy with the performance of QSC’s K8 loudspeakers. With their small size, it is not surprising that they are a little light on bass performance, which is where the QSC Ksub subwoofer unit comes into the game.

The Ksub is also a powered speaker assembly, using a built-in 1000-watt (2x500 watt) power amp. This class D amplifier powers two 12-inch drivers. The amplifier is cooled by an on-board variable-speed fan. The speaker uses a variable power supply (100 to 240 volts), and US and Euro spec connectors are both included.

Of course, the Ksub is the biggest and heaviest part of the PA system. The enclosure is 26-inches tall by 114-inches wide by 28-inches deep. It is made of birch plywood with a textured black finish. To ease transport, it has non-removable casters and nice recessed aluminum handles. This is important, as it weighs in at 74 pounds, or 33.6 kilograms (but the metric system will never catch on).

The Ksub has a 2 combination XLR/1/4” socket inputs. Also, there are a few controls, including a gain potentiometer, and a digital signal processing option switch for normal or deep modes. There is a polarity switch, in case you run into some noisy voltage. And lastly, there is a connector where you can attach a remote gain control. I could see cases where this would come in pretty handy, particularly when trying to get the speakers to blend in with each other.

The QSC folks came up with a nifty threaded socket on top of the enclosure where a speaker pole (included) can be attached. This makes for a tidy PA package, and eliminates the need for carrying around more bulky speaker stands.

As with the other QSC K-Series loudspeakers, the warranty for the Ksub is 6 years, which provides plenty of peace of mind.

The Ksub completes the package when coupled with the K8 speakers, and really kicks this mother out. It has a frequency range of 44 Hz to 148 Hz, and a peak output of 130 dB. With the separate gain contol, you can blend it well with the output of the main speakers.

The list price for the Ksub is $1199, with a street price of $1049. This is not much of a discount, and seems a little like price-fixing to me. Regardless, these are a great addition to the K8 (or K10 or K12) speakers, and it is worth your time to check one out.