QSC KS118 Direct Radiating Review (Testing + Alternative)

We research and review everything that we share and recommend on our blog and try to keep things up to date. When you buy something through our links we may earn a commission. Learn more about our affiliate disclosure and about us.

For venues that host performances, clubs, and AV production, the QSC KS118 Direct Radiating is an active subwoofer with a high output that produces outstanding low frequencies. The KS118 reproduces very low frequencies dynamically and musically while producing high sound pressure levels.

It has an 18-inch direct radiating driver and a 3600 Watt Class D amplifier. JL Audio 10TW3-D4 10” is another excellent option. The on-board DSP enhances and safeguards system performance while also providing cutting-edge features like the capacity to arrange two units in a cardioid configuration.

QSC KS118 Direct Radiating1

The sturdy container, which is quite portable, has four quiet casters and comfy grips. A 35 mm pole can be inserted into an M20 threaded pole receptacle for simple vertical deployment with full-range loudspeakers.

QSC KS118 Direct Radiating

41rmEdC+IJL. AC SL1500


  • High Output Active Subwoofer
  • 3600W Class D AMP
  • On-board DSP Optimizes

The QSC KS118 Direct Radiating 18-inch Subwoofer is our top pick for the most powerful powered subwoofer on the market. With a peak output of 3600 Watts and an average output of 2000 Watts, this subwoofer makes a huge sound that could fill even the biggest concert hall.

By far, the KS118 is the most powerful DJ subwoofer on the market. This subwoofer is the best choice if you want to play at big concerts or want to shake a whole dance club with a loud, booming sound. Unlike many other subs, the KS118 doesn’t have to give up sound quality to get a high power rating. Even though the sub is very powerful, it can make a clear, deep sound that is still balanced.

The QSC KS118 Direct Radiating 18-inch subwoofer has a great build quality and is built to last, but its great power rating is what we like most. Even when putting out bass that shakes the room and hits you in the chest, this subwoofer will last because it’s made of plywood and has a strong metal grille.

DJs and other musicians will like that this subwoofer can handle frequent, hard use in a professional setting without sacrificing sound quality. This subwoofer is quite heavy, but you won’t notice because it rolls on four wheels that make very little noise. No matter where you play, you’ll be able to move it to and from shows to make strong bass.

This subwoofer is great, and it beats my old JBL Eon by a long shot. Nowhere near being able to compete I now like VIP PRO AUDIO very much because their prices were fair. I buy everything I need from them.

  • Extremely powerful
  • A strong design and a durable shell
  • Deep mode is a lower frequency extension you can choose.
  • Wheels for easy transportation
  • It is very expensive
  • Hugely weighty


The phase response of the unit does not change when the crossover frequency is changed, thanks to some clever DSP magic. This is also true for the K.2 Series, which means the system works well right out of the box. Say that this unit has a lot of headroom. With full-scale pink noise coming out of my mixing console, the box was happily rumbling, and it took about 6 dB more gain at the box to even get the limiter LED to light up.

Being familiar with the KW181, I can say that this box is better behaved at high output levels, without the loud port chuffing and nasal resonances. This is a great example of how a “Max SPL” spec doesn’t always tell the whole story.

With a stated maximum SPL spec of 136 dB (peak, 1 meter) compared to the KW181’s stated maximum SPL spec of 135 dB, one might think that this box’s output isn’t much better than the KW181’s, but that is not the case.

QSC KS118 Direct Radiating 2

This thing is loud, and it’s loud in a good way. From what I’ve heard of single-18 subs in this price range, the KS118 is the clear winner. Its output is almost as good as that of another single-18 box I often use that is much bigger and heavier. In terms of how well it works for how small it is, it’s right in the sweet spot.

I took the subs to a few events to test them out; the most interesting was a puppet show that used forced perspective and spatial audio through an 8-channel distributed system. The production specs said that the subwoofers should be put under the risers where the audience sits.

Even though the venue already had two older single-18 boxes made by another company, I used the KS118s as an upgrade. While tuning and testing the system, they made a nice rumble that never got loud or rattly, even though they were stuffed under seat risers.

Product Comparison

QSC KS118 Direct Radiating is extremely powerful, with a strong design, and a durable shell. It has Deep mode a lower frequency extension you can choose. KS118 has a very high output with impressive low-frequency performance 3600 Watt Class D amplifier module. I will suggest QSC KS118 Direct Radiating because it has wheels you can move anywhere.

To Conclude

The new QSC KS118 is a single 18-inch subwoofer that sends sound directly into the room. A 3,600-watt class D amplifier powers it. It’s the follow-up to the well-known KW181, my favorite single-18 sub-long-time. I’ve recommended the KW181 for a few smaller venue installs and mixed a fair number of shows on it, so I was very excited to try out the KS118.

Onboard DSP offers up to 100 milliseconds (ms) of delay, 80 Hz or 100 Hz crossover filters depending on which full-range loudspeaker is being used, and an optional “DEEP” mode that increases LF extension.

Frequently Asked Questions

Does QSC KS118 come with a pole?

The QSC KS118 also has a pole socket with an M20 thread, swivel casters, and a rugged painted wood enclosure.

Does the QSC KW181 have a crossover?

The KW181 has an internal low pass filter, and QSC says the range of frequencies it can handle is from 38 to 124 Hz. The KW 181 doesn’t have a crossover or a high pass filter for sending mid and high frequencies to the tops.

How do you attach an active subwoofer to an active speaker?

You must use a cable with RCA connectors on both ends to connect your powered subwoofer’s line level input (or LFE input, if it has two line level inputs) to the T1’s smart subwoofer output.

What do QSC Speakers stand for?

Some of the first guitar amps had names like “Duck Amp” and “Quilter Sound Thing.” The company was called Quilter Sound Company, later shortened to “QSC,” and was known for many years as QSC Audio Products, Inc.

Similar Posts