All about QSC Speakers

[conanski]

Yeah this confuses me too. QSC hit a home run with the KW181, the live sound guys still love it because it seems to be perfectly suited to generating loud kick drum, it's easy to move with the wheels and not least of all it has been all but bullet proof. Many of the super high powered subs recently released seem to struggle with all that power, the EV ETX18 has developed a bit of a reputation for thermal issues if driven hard, and although I have not seen any shutdowns the high powered Yorkville subs I have used also get into thermal stress after a couple hours of DJ use and if you bother to keep an eye on it the limiters seem to activate pretty easily. QSC is an amplifier company first and foremost so while I would be skeptical about a 3600w power rating form some other manufacturers I'd be willing to believe it if this box delivered something extra over the KW181, but it doesn't. There are some drivers out there now that can handle this kind of power, BassBoss and Danley use them and their boxes do offer lots more lowend extension and/or SPL than the regular big brand name boxes so that power is getting used there but somehow it looks like QSC totally redesigned this box only to end up with the same results.

[Incognito]

QSC clarified a couple of things about the new KS118

Q. What is the difference between the KS118 and the
KW181?
A. There are many differences:
• Nearly double the peak power with a 3600W Class D
Amplifier (1800 W + 1800 W bridged)
• Custom-designed long excursion, tour-grade woofer
with 4” voice coil
• More powerful DSP, offering improved amplifier and
driver protection
• LCD display for advanced functionality and control
• Increased output (max SPL) and frequency response
(LF extension)
• Cardioid mode settings for directional frequency
deployment (requires two or more KS118 subs)
• Backing grille cloth (similar to K.2) for a clean,
professional look
• Can be deployed both horizontally or vertically

Q. On the Specification sheet, the Maximum SPL
(Sound Pressure Level) of the KS118 appears to be
only 1 dB higher than the KW181. Does the KS118
only go 1 dB louder than the KW181?
A. When measuring the maximum SPL of a loudspeaker or
subwoofer, the peak level is taken into account, but not the
QUALITY of the sound at that volume. While the KW181 does
a great job at performing clearly and loudly, in order to achieve
maximum SPL it is well into DSP limiting and protection, and
may not sound as clear at high volumes as it does at lower
volumes. With the larger amplifier and new woofer in the
KS118, there is significantly more headroom and dynamic
clarity before the onboard limiter and protection circuitry are
activated, giving you a clearer, fuller sound at higher SPLs than
you could previously achieve with the KW181.

So basically QSC is admitting to fudging the numbers on the KW181 a bit to reach their stated spec (not really surprising considering that it is sort of the industry standard to fudge the numbers a little for marketing).



https://www.qsc.com/resource-files/p...ks_118_faq.pdf

[conanski]

The put a similar blurb up for the K.2 fullrange boxes where it was "admitted" that the real world output of the original series was in the neighborhood of 5-8dB less than published.