DL and the K series

[WK154]

Being that QSC's K series powered speakers are a popular combo with the DL I thought that a quick check on the gain structure wouldn't be a bad idea. Well so much for the 5 minute check. First hurdle was the K series spec  sheet. No input values worth anything but lots of output specs. No problem call QSC and get the info and move on. Yeah 2 weeks later and the 4th call finally got me what I was looking for namely Max input signal value. Also since it has a limiter when will it kick in. QSC is not alone in this spec problem, apparently JBL, EV, Mackie etc. all are keeping this a secret. I had to go to Meyer Sound to finally get a manufacturer that provided the info in their spec sheet. The strange part is that none of them have a problem listing these values for their amplifiers. Go figure. Not to keep you in suspense too long the max input for the K series is 26dBu, including the sub, and the limiter kicks in at 22dBu. Is it a fixed value limiter or is it a soft knee compressor? Will you ever see max out of the K?  Let you know after the phone call. Well that leaves 5 dBu that the DL can't provide, it's max is 21dBu. You say who cares well we do know that a 50% reduction (3 dBu) in SPL will take place and more. This may be fine for folks that have a small gig in a bar or nightclub  but outside or in a larger venue it's a bit of a problem not getting max out of your gear.
Corrected for max power spec which is at 4 dBu with 0 dB settings on controls.

[RoadRanger]

I'm pretty sure those numbers are wrong. You can plug a mic into it and easily drive it into limiting. I suspect that in line input mode with the knob at "0" a pro line level (+4dbu) input will tickle the limiters.

[WK154]

I'm pretty sure those numbers are wrong. You can plug a mic into it and easily drive it into limiting. I suspect that in line input mode with the knob at "0" a pro line level (+4dbu) input will tickle the limiters.

Not owning one (K series) certainly puts me at a disadvantage. Ya'da thought that the Tech Guy at QSC would know his stuff, he's been around a while. I guess it's definitely time for another round of calls. I trust you have one of these. Actually Gio has two of them time to touch base.

[Keyboard Magic]

I noticed that even in a medium sized gym with about 150 people I had to push the levels and gain up on the school’s DL while keeping feedback at bay, to cover the whole area. Now my powered speakers are Yorkville Elite E10 powered cabs, with 325 watts program each which is average horsepower for small venues, but they do cut through the background noise quite nicely.

They’re okay for most things, but you are correct about the gain structure of the DL being low, if I interpreted you're post correctly, even though you were really trying to find out about the K's. Now this is the school’s DL and its appears to be working just fine for what they need, better than my DL did, but I am thinking of getting more powerful speakers to compensate and getting new cabs for yourself is just cool. It's always fun to get new toys now and then. 

Haven't decided on what yet, but they will be Yorkvilles 'cause they're super reliable and I can get a good trade in value on my Elites.

[RoadRanger]

Not owning one (K series) certainly puts me at a disadvantage. Ya'da thought that the Tech Guy at QSC would know his stuff, he's been around a while. I guess it's definitely time for another round of calls. I trust you have one of these. Actually Gio has two of them time to touch base.

IME companies require their tech line guys to follow the script and anything off-script will get you BS answers. And yah, the manuals these days all suck - not limited to any particular manufacturer. Probably because they are all written by marketing these days with no engineering oversight. Oh, and I've only used them, never owned one - they seemed about as sensitive as any other speaker in their class. In the absence of specs one can assume that a +4dbu pro line level signal can drive any of the modern powered speakers to full output which gives you plenty of headroom to overdrive them +12db into the limiters without clipping your source which seems to be the prevailing wisdom as to how to set your gain structure these days.

[WK154]

Not owning one (K series) certainly puts me at a disadvantage. Ya'da thought that the Tech Guy at QSC would know his stuff, he's been around a while. I guess it's definitely time for another round of calls. I trust you have one of these. Actually Gio has two of them time to touch base.

IME companies require their tech line guys to follow the script and anything off-script will get you BS answers. And yah, the manuals these days all suck - not limited to any particular manufacturer. Probably because they are all written by marketing these days with no engineering oversight. Oh, and I've only used them, never owned one - they seemed about as sensitive as any other speaker in their class. In the absence of specs one can assume that a +4dbu pro line level signal can drive any of the modern powered speakers to full output which gives you plenty of headroom to overdrive them +12db into the limiters without clipping your source which seems to be the prevailing wisdom as to how to set your gain structure these days.

I wouldn't be so quick to wrap everything in the +4dBu wrapper (holds true for antiques). Here's my take on it. Their GX5 which I have has a max input of 26dBu (sound familiar) and according to the engineer (I called him a Tech guy but he's not your normal tech support variety) gave me the numbers. That means 26dBu is the clip limit. I also found out via the fine print (6point type) that the input can be clipped without triggering the output limiter. Makes for interesting sound effects and may explain the 22dBu limit presumably output. That means that they can handle mixer output from 16dBu to 26dBu with their 10dB of amplification. Meaning that the DL should be good to go as long as you apply 5dBu of amplification in the K series (gain knob). Some good info on their forum for most of their product.
Correction

[RoadRanger]

Their GX5 which I have has a max input of 26dBu (sound familiar) and according to the engineer (I called him a Tech guy but he's not your normal tech support variety) gave me the numbers. That means 26dBu = max power out.

No, that means that the amp's input will clip just above 26dBu. With the amp's input attenuator up full the amp will get full power with about a +4dBu input which gives you about 22dB of headroom to push the limiter into compression. I actually had one of those and I had no problem hitting the limiters at about the zero dB output level on my mixers' VU meters. BTW IME pushing more than 6 dB into the limiters doesn't gain you any volume and starts to sound squashed and pumped.

[WK154]

Their GX5 which I have has a max input of 26dBu (sound familiar) and according to the engineer (I called him a Tech guy but he's not your normal tech support variety) gave me the numbers. That means 26dBu = max power out.

No, that means that the amp's input will clip just above 26dBu. With the amp's input attenuator up full the amp will get full power with about a +4dBu input which gives you about 22dB of headroom to push the limiter into compression. I actually had one of those and I had no problem hitting the limiters at about the zero dB output level on my mixers' VU meters. BTW IME pushing more than 6 dB into the limiters doesn't gain you any volume and starts to sound squashed and pumped.

You're right my wonderful engineer was confused about max power and clip level. Good to know that +4dBu is still the target for max power. If I had RTFM and paid attention input sensitivity was right there on the GX5 spec at 1.2V rms or +4dBu. As to the gain structure with the DL I would still set the K gain at +5 dB and go from there. If it starts to sound squashed then they're using crappy drivers. As I now understand the K series a little more it is actually dual 500W supplies which means even less of the 1000W will be used since a balance between high/mid and low must be struck. All of the above of course was based on the standard sine wave test signal, throw in music and it's a whole different world (far less power used). When all else fails I actually went back and did the math and in the process found an interesting article from Peavey on amps.  http://peavey.com/support/technotes/soundsystems/Voltage%20Gain.1.pdf
Worth a read even with the math.