4 - K12's and 2 Ksubs in a Middle School Cafeteria - HELP!

mgfliby

Okay, here we go. We are a portable church that struggles with sound. We have 4 K12's for tops and 2 Ksubs in a very big (40W x 75L x 25H) sterile cafeteria. We put up pipe and drape around the entire room, with 150 chairs, carpet is laid everywhere except where the chairs are.

After reading a lot of the posts in here, I feel completely retarded in my setup. I am first going to re-do the Gain structure as I do not believe it was done correctly the first time, or at all at this new venue. After that, I'm not sure what to do next.

I am a little lost and want to do it right. If anyone is willing to help a church in North, GA I would be forever grateful!

Thanks,

Matt :oops:

Gadget

It's ok Matt...
Were here to help...so... 4... 75 degree conical pattern speakers...hmmm so let me guess... aw heck I'm not good at guessing anymore...so are you using them in a strait line across the front, or splayed out, or are you using the second pair as delay speakers half way back..

Some pictures would be helpful.. drawings if nothing else.. you haven't given a whole lot to go on here...

You put this in the DRPA/PX forum so we have to assume you have which? Hmmm I guess we already determined that I'm not good at guessing.

So how about a little help here...

All the info would be nice.. do you have the measurement mic? are the speakers on stands? e are the subs placed? so many questions...

MORE please...no detail is too small (well not actually but it sounds good)
Gadget

mgfliby

See, I told you I needed help! LOL

1. DriveRack PX and a Soundcraft Series 2 console

2. Speaker arrangement: Okay, as of last week (i said i needed help) the k 12's are on stands, to each side of a 24' stage, as close as possible to each other, but the inside speakers are turned in for center coverage and the outters are facing the outermost seats of the crowd. The kSubs are side by side now, in the middle of the stage, thus center of crowd and room.

3. The room is wide, tall and deep although the coverage area we need is only approximately a 30 x 50 total area as we do not need all of the space in the room as of yet.

4. I have the provided RTA mic.

4. Running stereo, 2 tops one Sub per side.

Gadget

Ok Matt... were gonna get you through this...hope no one gets killed... :shock: 8) sorry but I digress...

Sounds like you don't need the second pair of K12's (yet) and your exacerbating the problem....by using them...

I'm just full of good news aren't I????

Here's the deal... 75 degree conical coverage means that you have 75 degrees of horizontal AND vertical coverage for EACH speaker...(this is the HF part but it's also the stuff that bounces around and causes feedback and all sorts of crap) if you had one per side you would be covering 140 degrees of horizontal coverage... "So Gadget, Why is that important?" you ask... Why that's a really intelligent question Matt... (Dude we REALLY have to quit meeting like this... )

Ok all levity aside.. what we NEED to do here is get the message ON the people and OFF the walls.. and ceiling (the floor would be a benefit... BUT that IS where the water bags are sitting... (they ... the water bags...will absorb the sound and keep it form bouncing around) We also need to keep the High frequency sound patterns from the speakers from overlapping..."Why is this important" You ask? Again, a good question... Because when those patterns overlap (worse when the speakers are in close proximity) cancellations and all sorts of sonic chaos happens.

Ok, now lets look at a perfect setup and see what we can gleen form it...

The room is 100 feet wide, and 150 feet deep.... the stage is 30' wide and 20' deep. The ceiling is 30 feet high... the congregation is wrapped around the pulpit and are on the left and right of the stage as well as all the way back... the speakers are 60X40 degree coverage and are hung @ a trim height of 25" aimed down so that they cover the congregation and keep the sound ON the people and OFF the walls... and ceilings...the speakers are clustered in the center... over the pulpit and with the sides of the speakers touching so that the coverage patterns are seamless...

This ideal world is NOT going to be possible for you (at least not right now...)but with a little creativity we can see if we cannot make this work.

So... lucky you... you happen to have the tilt direct feature already built into the K12's... simply turn the speaker over... on the bottom... turn the speaker pole cup to the 7.5 degree position... this will allow you to tilt the speakers down 7.5 degrees, and allowing the energy to get on the people and off the ceiling...

Now.. I would suggest using the other pair as front fills..and shading them (turning them DOWN with respect to the other speakers) (covering the front seats only ... pretty much) Later, when the congregation grows you can use the second set as delay towers but you'll need the 260 for that... because the PX has NO delay and the DRPA+ has only 10 feet of delay...


Now... YOU have some work to do... some reading...
viewtopic.php?f=61&t=959
system setup and tuning... be sure to cover these subjects listed in the setup guide...

Here is a good progression of things to read next:
viewtopic.php?t=960
viewtopic.php?t=949
viewtopic.php?t=1617
viewtopic.php?t=1384

Be well
Gadget

P.S. we'll get you through this...

Dra

If you sent a PM to me, it got zapped when the forum was hacked. Please resend.

DRA

Gadget

I emailed you... but not PMed you here...I don't know what happened or where the threads went.. I'm waiting to hear from Adam.
G

mgfliby

Thanks, i got it but instead thought for the success of this forum, I should post my comments and questions on here so others can possibly use them.

This is a response to your PM:

Okay, and for clarity I have a couple final questions:

1) Since I am using the provided RTA mic, do I set it up with the tip facing the speakers, as close to the floor as possible? I see that you had one that was pointed at plywood.

2) Do I place the mic just in front of one of the tops (R or L) leaving the subs in the middle of the stage, thus center of room?

I just am a little confused as to how the speakers need to be arranged when doing this.

Thanks a bunch. Only two more days until I can set-up...it's killing me!!!

Gadget

If you could get in there before the chairs are in place... but the carpet is down...place the mic on the carpet about 25 feet out aimed @ the speakers...(make sure the speaker and mic are in the center of the carpet if possible) probably best to place the sub under the top, or skip the sub all together (indoors the bass will NOT be accurate because of standing waves and modes)

Outdoors... (The best way) would be away from all reflective surfaces... then put the mic on a stand about 15-20 feet out. and crank the speakers up pretty loud (the louder you turn the speakers up the farther back the mic can be)

You probably should do both and then compare the two and see what the room is doing to the sound.

The picture is of a technique that turns the mic into a PZM (pressure zone mic) and requires a hard surface and a very close proximity to the surface to make reflected energy less of a problem.


Gadget

mgfliby

Great, will do! Look forward to seeing the results. I will skip the Subs the first time. Then see what happens with the subs in center, then under a top, etc and compare results.

Again, I will send you the results and ask for next steps Saturday. I have internet access at the school so, maybe I can catch you online around 3pm or so.

Matt

Gadget

When you do the service... get the tops as high as possible and use the 7.5 down angle and try to aim the speakers so the sound stays off the walls and ceiling as best you can.

The center fills/fill should be only as loud as necessary to cover the first couple of rows...

G

Dra

When I use center fills, I like to bring the center level up just to the point of hearing the center with the sides, not to the point of being louder than the sides.

Are you going to set up the center as an output or just daisied off the mains?

DRA

mgfliby

I will have to daisy chain the center fills unless I want to run the L & R tops as a MONO pair. I will daisy chain and then just dial back the gain to only cover the first couple rows as suggested. We just had this setup problem in our Main campus theater.

Another thought. Is there any advantage to running Subs as a stereo pair? Or can I for the sake of one less 100 ft cable, run it MONO and daisy chained? (they sit right beside each other, front and center)

Matt

Gadget

With the PX there really isn't any mono anything so you might just as well think of it as dual mono with the same treatment for both. Yes I'd just daisy chain the subs, and feed the same info to all the tops and just power shade them.
G

mgfliby

Great, I am actually heading to the school today. Hopefully, I can get some good results.

mgfliby

OMG...

I did the Gain Structure (correct this time) and here is the result. The first setting is the original setting, second setting is new. I gave myself 4-5db of total headroom until limiters kick in.

K12 Tops L &R 0db : -4db and 7.5 tilted down
K12 Center fills (new arrangement) N/A : -7db floor wedge position, on floor, front of stage, facing crowd
KSubs +10db : -5db

I played via iTunes one of our worship sets and was BLOWN AWAY at the clarity of it all, highs, mids, lows you could feel, etc. It was amazing. Then I went back to the drive rack PX and realized that this was with the GEQ and PEQ all OFF (flat)! I then said oh, let me just click the GEQ back on and...

YUCK! The nastiest sounding CRAP I have ever heard started playing through my speakers. Unfortunately, the room already had the chairs, storage tubs, and people (about 20 all running around the cafeteria) so, I was unable to re-EQ the speakers as I wanted to. This will happen tomorrow.

Instead I flattened all of the GEQ settings and only boosted the 80hz and a few of the highs for vocal clarity and guitars as directed by Gadget. HOLY MOLY! I was not in tow with my favorite CD but rest assured, tomorrow will be a big day in that cafeteria.

The center fill idea was brilliant! As I indicated above, they are manually shaded (turned down) by the Gain dial on the back to -7db and daisy chained from the tops L & R. From the front row, you can just hear the top L and R's. From the second and third rows, it a pure magic blend! My campus pastor walked in and was loving it. He asked if he can bring his Dan Fogelberg and KISS cd's in to "help me" EQ the room tomorrow. LOL

Whew, it was hard to leave but I had to watch my daughter cheer. :-) Good stuff guys. I'm on cloud nine from sound stuff...is that sad?

Talk soon!

Gadget

:-) Good stuff guys. I'm on cloud nine from sound stuff...is that sad?

Sad? No, sad is what you were when you came here right? Think about it... were thousands of miles apart, never seen your room or system.. and with just some good old tried and true sound reinforcement techniques and a little creativity we got you to the point you never thought possible... and were just getting started...

One thing, those boxes are pretty darn good already, and shouldn't need much..I would just try taking one top outdoors and see what a flattening session outside does.As for the subs.. by ear only, try a PEQ @ 60 hz with a Q of about 5 and then cut till it pulls the low boom is gone, and one @ around 100 hz with Q about 4 and cut it about 3-5dB and then move it up and down till the low mid howl is tamed. (these are likely room modes BTW) another common one is in the 250-500hz area, so set up a fairly broad Q of about 1...that is a cut frequency also...theses are not MANDITORY but try them and see what you think...only use as much as you need to tighten things up.

Well congrats! keep up the good work!
G

mgfliby

I'm with you on this. I would be curious to take one K12 outside and see what I can get from it. I'm now a big fan of saving numerous pre-sets for different types of music, sound, etc. Since we don't venture too far from a genre of music, we do on occasion have a need to throw in a loud rock tune. Most recent, "Runnin' with the Devil" :twisted: by Van Halen. Would have been nice to have tweaked the room a couple months ago and literally blow the peeps away with that intro! :-)

I'm all over it with the PEQ and the subs. I still need to set the crossover points (tops and subs) as the PX is a little different in accessing these. I couldn't do it yesterday without the manual handy.

I shall report back tonight! Hope you have a great Saturday...

PS - What do you do full-time? Sound? This forum? Just curious....

Matt

Gadget

Hi Matt..
I'm strictly a volunteer ...I was such a pest they just asked me to moderate
Probably easier to tell you what I DON'T do than what I do
I have several businesses
Advanced Auto and small engine
Twilite Zone Productions/DJ/KJ/livesound
Studio "G" (recording studio)
Electronics repair
speaker re-cone
speaker builder
instrument repair
and "Guru "G" home improvement ( yes, my customers CHOSE that name.. I guess I have pulled off some amazing feats...One was a bathroom that has a brass plate "the Gary memorial bathroom... he really knows his S***"

You get the idea.. enough of the self aggrandizement..

Be well..
G

mgfliby

Sorry for the delay and getting back to you. I was finally able to get in and tweak the PEQ for last weeks services. WOW...what a difference so far. Last weekend was probably the tightest sound we have had yet in 10 mths of services.

My only remaining questions are these:

During the PEQ setup, it asked me to flatten or restore...I chose flatten. Then to choose, BELL, HSHELF, LSHELF, LHSHELF...which one is recommended in my setting? I chose Bell?!?! Seemed to have worked but don't want to make my life harder for nothing.

Finally, the compressor on the PX. Any general recommendations for live music settings? Use OverEasy? VariKnee?

Thanks so much! Hope all is well.

Matt

Gadget

Well.. if you "flatten" the EQ you ELIMINATE it... "Restore" and you have the Eq in the chain again

Low shelf is for the bass and it effectively tapers off the bass at the slope you set, and at the frequency you set... the high shelf is just on the high end of the spectrum... and a bell curve is just that a center frequency with a rate of fall off (Q... the smaller the number the more frequencies are affected.

Download the GUI and install it.. insert the 260 and play with the different modules.. it will give you a better idea what your doing (visual)

If your using my PEQ suggestions 60, 100, are bell on the subs 180, and 350 are bell and 3.5K is a shelf
G