Outdoor shows...

[Donnie Frank]

Hey doods!

So last weekend I mixed a couple bands at an outdoor show. I do NOT own a large, outdoor P.A. system, and haven't done an outdoor show in years, so I cobbled together the following:

* QSC K12's x4 (2 per side). Speaker drivers were meticulously aligned. Both speakers faced forward about a foot forward of the front line, perfectly parallel to one another (not splayed), with about 1/4" of space between speakers. Is this the best way to maximize efficiency?

* JBL SRX728s x2 (3600 watts each for a total of 7200 watts) (love these subs - best ever).

* FOH was set up roughly 60' forward of center stage.

Now, I realize that K12's are not long-throw speakers, and therefore not really great for outdoor shows. But I have to say that I can't believe how short the throw of these beasts really are. From FOH it felt like I was pushing about 104dB, which is a comfortable mix for me. A mere 20' closer and one could hear that the speakers were louder than F***! Wow...I can't believe the difference 20' makes! Clearly, I was pushing the top boxes to their absolute limits, and, other than that 40' bubble around the front of the stage, it was NOT that loud. The Subs didn't complain at all and were run well within spec. So here I am asking for advice again...

I don't have a huge budget, so buying a real array is not an option. Would adding another pair of K12's help? The K12's are 1000watts each, so my highbox/sub ratio was 4000:7200, which seems good to me.

At this point I'm merely looking to get a little more out of the mains. I'd like to use existing gear or gear that's not specific to this one situation. That's why I like the K-series because they can be used for a myriad of situations. So I don't mind buying more of them.

In the old days I used my SRX712m speakers for mains @ 1800 watts/each, and they seemed to do a lot better than the K12's. I still have 4 of those JBL's, but like the active speakers. Might have to go back to those JBL's. Just spit ballin' here....

Thanx in advance for any help or advice.

Regards,

Donnie

[cgrafx]

The K12's are not designed to array. If you have to use two the likely best orientation would be approx 140 deg of coverage.

You can't simply put more of them up and expect better results when they aren't designed to work together that way. Yes you will push a bit more air, but they still aren't going to throw long distance and the comb filtering will create dropouts all over the place. The more you put up per side the worse it will get.

You need to have speakers that are designed to array or you'll just end up with a sonic mess throughout the audience area.

The SRX712m is even worse from an array standpoint. They are 90 degree horizontal coverage (which just makes the area of overlap bigger and increasing the comb filtering problem).

Just guessing from the available info about the best orientation for two K12 boxes per side is with one splayed as if it were sitting on the other like a floor monitor.

Adding more than two per side will just make the sonic field worse.

If your JBLs push more volume individually you might actually be better off with a single pair of the SRX712's, but again not designed to throw long distances.

[Donnie Frank]

The K12's are not designed to array. If you have to use two the likely best orientation would be approx 140 deg of coverage.

You can't simply put more of them up and expect better results when they aren't designed for to work together that way. Yes you will push a bit more air, but they still aren't going to throw long distance and the comb filtering will create dropouts all over the place. The more you put up per side the worse it will get.

You need to have speakers that are designed to array or you'll just end up with a sonic mess throughout the audience area.

The SRX712m is even worse from an array standpoint. They are 90 degree horizontal coverage (which just makes the area of overlap bigger and increasing the comb filtering problem).

Just guessing from the available info about the best orientation for two K12 boxes per side is with one splayed as if it were sitting on the other like a floor monitor.

Adding more than two per side will just make the sonic field worse.

If your JBLs push more volume individually you might actually be better off with a single pair of the SRX712's, but again not designed to throw long distances.

Thank you for taking the time for such a well thought out reply. Good information here. I had a feeling "comb filtering" would come up. So basically I can WIDEN the throw by splaying the cabinets, but I can't really EXTEND the throw by coupling them. That makes a lot of sense.

I have a bit of a budget, but not a huge budget. The QSC KLA12's look good...but spendy...yikes...Any recommendations?

[cgrafx]

The KLA12 is 90 x 18 degree box. Its designed to array vertically, but not horizontally. Free standing its still only two boxes otherwise you have to fly them.

Actually line array in this context is a bit of a misnomer, as a true line array needs to be 8-10 feet in length before you really get the benefit of what a line array is designed to do, which fundamentally is even out the volume level between the front of the stage and the back of the venue.

Two of them on sticks is really just a point source array, not a line array

Here are some actual point source options designed as arrayable speakers

Turbosound ta-500
EAW KF300
EAW KF650
EAW LA460 (I use 4 of these - 2 per side plus a pair of EAW LA212 on sticks for front of stage coverage)
Meyer JM-1P

None of these are particular cheap although the EAW stuff listed is older and only available on the 2nd hand market.

The KF650's are great speakers but really need to be driven as 3-way tops so three amps and the processor to go with them

I run my LA460's as passive 3-way tops using the built-in x-overs over LA128 subs. (So amplification wise its a two-way system Tops and Subs)

Everything is driven with two QSC PL380 power amps (approx 14000 watts between the two) and I can very comfortably cover 1000-1500 people.

[Donnie Frank]

The KLA12 is 90 x 18 degree box. Its designed to array vertically, but not horizontally. Free standing its still only two boxes otherwise you have to fly them.

Great information here. Thank you!

Correct me if I'm wrong, but wouldn't 36° of vertical coverage be enough for your average small outdoor event? In my mind, it seems like the audio is being concentrated where it needs to be, in a fairly narrow vertical band, but a wide, 90° horizontal band. I get what you're saying about the line array, which allows granular customization of each array element to facilitate even coverage over a wide seating arrangement. But for the purpose of these smaller outdoor shows, it seems 36° of vertical coverage starting @ roughly 7' above ground and shooting straight out towards the audience would work. Dare I say that even a single cabinet per side with only 18° of vertical coverage might actually work, too?? Thoughts?

Actually line array in this context is a bit of a misnomer, as a true line array needs to be 8-10 feet in length before you really get the benefit of what a line array is designed to do, which fundamentally is even out the volume level between the front of the stage and the back of the venue.

Yep...that makes total sense.

Two of them on sticks is really just a point source array, not a line array.

Copy that. It seems the KLA12's could be used as a point source array in a smaller outdoor situation.

Thanx for the EAW recommendations. I may go the passive direction, but for now I'd like to see if I can find an active solution. Please share your thoughts.

Regards,

Donnie

[cgrafx]

Great information here. Thank you!

Correct me if I'm wrong, but wouldn't 36° of vertical coverage be enough for your average small outdoor event? In my mind, it seems like the audio is being concentrated where it needs to be, in a fairly narrow vertical band, but a wide, 90° horizontal band. I get what you're saying about the line array, which allows granular customization of each array element to facilitate even coverage over a wide seating arrangement. But for the purpose of these smaller outdoor shows, it seems 36° of vertical coverage starting @ roughly 7' above ground and shooting straight out towards the audience would work. Dare I say that even a single cabinet per side with only 18° of vertical coverage might actually work, too?? Thoughts?

I wasn't actually commenting on the vertical coverage and yes even a single box could work for a small audience. I was really just pointing out that 2-boxes doesn't make a line array and that the array is designed to work vertically so you can put more of them up next to each other.

Copy that. It seems the KLA12's could be used as a point source array in a smaller outdoor situation.

Thanx for the EAW recommendations. I may go the passive direction, but for now I'd like to see if I can find an active solution. Please share your thoughts.

Regards,

Donnie

The current manufacturing trend has been in the line-array styled boxes like the KLA12's. Lots of manufactures using this design. JBL, QSC, RFC, etc all have offerings that are perfectly usable. As to how large a show you can handle, you'd have to try them out to determine that.

There is a lot to be said for these style of boxes. They tend to be lighter in weight, physically smaller and pretty easy to setup.

In my circumstance the EAW LA series stuff was a good fit. They are a significant step up from QSC K8/10/12 type boxes and most of the other MI series stuff from other manufacturers. I seriously considered moving into the EAW KF650 range, but it would have made my amplification setup more complicated. The LA460 box is very similar to the KF650 but can be run fully passive on a single amp. The KF650 is either 2-way or 3-way so would at a minimum have required at least one more power amp which I didn't want to add into the mix.

Right now my entire rig rolls in as a single rack stack (mixing console & amps on bottom and wireless gear on top). I'm running two QSC PL380s for FOH Tops/Subs and a Carvin 4-ch amp for floor wedges when needed. (Full system is two stacks per side instead of the single set shown below). I only need to run a single 4-wire speaker cable to each side of the stage and then jumper from box to box.

System is 32 in/32 out, 5 stereo IEM mixes, 4 Floor wedge mixes, 2 wireless hand helds, 4 stereo wired XLR channels (L/R rather than balanced) for keyboards so single mic cable to each keyboard wired direct to preamps without need for a DI, and an AVB (Audio over ethernet) out that is currently setup to give me 24 of the 32 channels available as a FOH split when we play shows where we are only handling our stage mix.

The single rack stack scales from" just wireless IEMs and mics" to "two speakers on sticks" to full the rig of "4 double 18 subs, 4 three way tops, 2 FOH infills and 4 floor wedge mixes + 5 wireless IEMs + 2 wireless mics"

[beau]

I would recommend that you call someone you know that owns a pair of kf300’s, kf360’s , jf260’s or even better all three.
If you are willing to accept cheap Chinese made class d power amps in active speakers, I recommend trying it for your older passive boxes as well. Passive speakers aren’t more inconvenient if your amp rack only weighs 10lbs and sits next to your speakers.