By Mark Farmer
QSC Audio is a name I have always associated with high quality sound reproduction by an amplifier company. Although I am a user of one of the larger amplifier company's product, I have great respect for the difference in spending a little more can make. I still have a great memory of the theater where I first heard/listened to QSC Amps. The system sounding like a high-end home system. In the world of amplifiers this kind of tone becomes truly important.
The newest line of QSC Amplifiers is the PowerLight™ series. The PowerLight 1.8, stepping in at 450 watts at 8 ohms doesn't even begin to show what these amps can pump out.
Features
PowerLight amps measure in at 17.4 lb.. on the mass scale. Showing what is really in a name can be oh so true! I had to open up the box, upon receiving my amp, just to see if the product was actually there. For a two rack space unit, the PowerLight 1.8 packed quite a punch at 450 watts per channel at 8 ohms. Power ratings jump to, 700 watts at 4 ohms, and 900 at 2 ohms. These output power measurements are all from a 1 kHz tone at 1% total harmonic distortion. Bridged mono numbers are truly amazing at 8 ohms, with 1300 watts at 0.1% THD and 1800 watts at 4 ohms with 1% THD. Frequency response was measured at 10 db below rated power. Plus or minus 15 db at 20 Hz - 20 KHz, covers the entire spectrum altogether. The -3 db down points are so far out, at 8 Hz and 100 kHz, that it should be of no concern. Unweighted noise is 105 dB below each amplifiers rated output. All three QSC PowerLight carry a rated damping factor of 250+ at 8 ohms. With a voltage gain of 34db and input sensitivity of1.14v this amp should have no problem generating some fantastic output levels.
At first glance of the front panel, you would notice basic high end amp features, but in addition there are some fancy bells and whistles engineered thru out. A power switch, channel 1/channel 2 gain controls, and some input LED's being standard. One of the fancy features are the LED's beside the power switch. The three LED's being, red for "protect", yellow for "standby" and green for "power". The "protect" light operates to show you the outputs are being muted for 3 seconds before turning on and turning off. This light also alerts you of thermal overload, causing the amp to mute both outputs, and un-muting after the amp cools down. The "Standby" light utilizes the "power supply control" features. This informs you of shorting of the terminals or not. I'll write more on this feature later.
The rear panel is even more remarkably designed. Two great items of note, one being the banana plugs which are recessed and flush with the rear panel. Second, which is one of the most space saving connectors I have ever seen. QSC calls it a "combo" input connector. Basically, it is a balanced or unbalanced 1/4" connector mounted inside of the XLR jack. Furthest to the left is an unbalanced barrier strip for a hard wire install. To the left of the input connectors is the 3-way Parallel/Stereo/Bridge switch. Centrally located is the cooling fan, to provide uniform air flow over all circuits. The "power supply control" I wrote of earlier, is a two screw barrier strip also located on the rear panel. This shorting of the screws inhibits the switching power supply and limits power to the audio circuits. The "Standby" light glows, keeping a small amount of current to the capacitors in turn, alleviating bursts of on/off current flows. The "power supply control" also allows you to daisy-chain of several of your favorite "PowerLight" amps in your house or monitor racks.
In Use
I first plugged in the QSC amp, turned it on let it sit for a "burn in" period. My portable CD player became my first input into the amplifier. Using the left and right handy "signal" LED's, I set both channel inputs to right around -100 dB letting the yellow LED's glow consistently. According to the manual, it is acceptable if the red "Clip" indicators flash on occasion. Hoping to test the limits of the amp, I ran inputs up till I received "red" and backed them down just a bit.
The cabinets used, were a small custom STI Nugget. Inside of the boxes are a 12" speaker and a 1" horn driver. Applying the QSC to these boxes was short of remarkable. I auditioned some familiar music, and let the volume rip. What I heard, compared to other amps, was a natural and uncolored sound. There seemed to be no unnatural tones heard or added emphasis on any frequency. During speech tests, which were done with a Shure SM-58, I also heard no extraneous tones added to the sound.
Turning to the amp to provide some power for sub cabinets, I hooked it up to front loaded 15" ported boxes. The 450 watts at 8 ohms seems pretty accurate with the severe thump pounded out by this "Light" little amp. I also heard no turn on thump associated with some power amps. Since the sub speakers were 1000 watt drivers, I configured the amp to "Bridge Mono" to try out the complete potential of the amp. At 1300 watts rated power, my sub boxes woke up from their nap. Big, dynamic, and very loud bass at 90 HZ and down hammered me very hard. During the testing, at no point did the amp go into thermal overload or shut down.
Summary
In the course of these tests, I kept saying to myself, if I only had any one of the "PowerLight" series amps to take home and use on my home stereo. In my opinion, this amp sounded that musical. Dance clubs, D J's, take note of this amp. The pure, high quality, rich sound this amp provides is unmistakable. Church installations, would be a given, for the untainted, noise free, value of the QSC "PowerLight" Series amps. Priced at around ? Retail these amps can be a great tool for your speaker cabinets.

Mark Farmer is a sound engineer with Stage Tech Inc. and a contributor to Pro Audio Review. He can be reached via the internet at: mixthat@columbus.rr.com

Product Overview
QSC Powerlight™ 1.8

PLUS
+Weight
+"Pure" And "Clean" Sound Quality
+Design
+3 Year Warranty
+Technical Online support

MINUS
-None