K series & SRX

koshy55

I have a electronic show coming up in a 5,000 sq foot room. 300-450 people

I am renting some subs to supplement my system and was wanting some advice. on signal chain and drive rack settings.

equipment available
mixwiz 16
driverack pa
2 kw12's
3 k10s
3 k subs
2 SRX 728 ( the older style)
2 qsc plx 3400's


This is my plan
Limit on Over easy 2, 18db
DBX hi - K 12's level 0.0 db, 100hz high pass, bw18, LR 24
DBX mid - 2 Ksubs level 0.0db, 50hz high pass, 100hz lowpass bw18 LR24
DBX low - SRX / QSC 3400 bridged mono per dual 18, level -4.3 db, 32hz high pass, 80 hz lowpass bw18, lr 24 ( amp at 100% gain )

Mixwiz Aux 1 fill, 2 K10's on the deck/ or on the subs laying wedge style, internal dsp.
Mixwiz Aux 2 Or DJ Mixer for monitor mix - 1 k10 1 ksub internal dsp



So each side would have Ksub pole and Kw12 and center clustered srx's.
I also thought about setting the stage up in the corner of the room pointing towards the middle of the room.

1) are these Driverack settings correct.
2) is this a good way about going it for the signal chain
3) would corner loading the stage setup be helpful or more trouble than its worth
4) any other suggestions

Dra

Just to be clear... is this an electronics show (gadgets and gizmos) with backgroud music and announcements, or an electronic (music / DJ) show?

DRA

koshy55

DJ show

Cybernalt

"are these Driverack settings correct?"

Trial it somewhere and Listen.

Dra

Check out this thread.
viewtopic.php?f=3&t=3075&p=17059&hilit=horn#p17059

Dra

koshy55

"are these Driverack settings correct?"

Trial it somewhere and Listen.

I am renting the subs and amps. I only have them the day of the show.
I am wanting a good game plan before i get to the venue.

I would love to do K12s at 160hz Ksub 160hz - 80 hz and SRX 80hz - 32hz.
I think the Ksub would be great for mid bass. I can not set it up like that though because the KSUB's DSP is set at 100hz-44hz and to my knowledge you can not defeat it .

Would I be better of not running the KSubs at all ?
I have ran them from a aux send at a rock venue and they summed with the house subs fairly well.

I do not want to risk damaging the rented subs either. would that be the correct comp/limit settings be
Limit on - Overeasy 2 , 18 DB

Thanks for the help and advice.

Gadget

All right, I don't see what you mean in a few instances...I checked out the K subs and the -10dB frequency response is 44 Hz - 148 Hz, the 3dB down response is 48 Hz - 134 Hz. therefore, you could use any of the response in there for your purpose...That means you might need to EQ the subs a little in the 150hz range to get it audible but it's there for use none the less...

Yes a midbass application is likely the best use here...

In order to get 32 hz out of the JBL's you would need heavy handed equalization as well but you would risk damage...also...Those are some power hungry devils that 3400 watts will only get started with that kind of power...

I can't tfor the life of figure out why you would list two crossover points in every instance.

DBX hi - K 12's level 0.0 db, 100hz high pass, bw18, LR 24

DBX mid - 2 Ksubs level 0.0db, 50hz high pass, 100hz lowpass bw18 LR24

DBX low - SRX / QSC 3400 bridged mono per dual 18, level -4.3 db, 32hz high pass, 80 hz lowpass bw18, lr 24 ( amp at 100% gain )

I might have guessed Hipass/ Lowpass but there IS no Lopass on the hi outs :?

My rec's:
JBL SRX728 HPF 35hz BW18 LPF 55hz LR24
Ksubs HPF 55hz LR24 LPF 130hz LR24
K12 HPF !30hz LR24

As for the limiter... use your gain structure to determine your clip potential, and don't exceed it... set the limiter as an OOPS and don't depend on it to protect anything from long term over driving...in other words don't allow anything to clip! The k series limit themselves anyway...and you cannot defeat them.

koshy55

I have been mistaken this whole time. For years now I thought the KSub internal dsp was set at 44-hz to 100 hz.

I'm really happy about this. I can take some of the low end strain off of the Kw12's and not have frequency overlap between boxes. Ksubs can do the mid bass and srx's can do the sub bass .

My rec's:
JBL SRX728 HPF 35hz BW18 LPF 55hz LR24
Ksubs HPF 55hz LR24 LPF 130hz LR24
K12 HPF !30hz LR24

Perfect !

Do I need to lower the DB setting on the JBL's to -4.3db ? or should I run all outputs on 0.0 db ?
I saw the -4.3 db on the jbl tuning speck sheet

Sorry If my questions were redundant. I did search the forum extensively before posting.
I just want to be prepared.

Thanks again for you time and patience

Dra

You might have to call QCS, but although there is DSP, it is unclear what it is doing. Likely low end protection and some EQ tweeking, but the description is "BAND PASS". Is that electronic or acoustically through the box design. In other words, what causes the -6db and -10db cuts on the high end? It is definately not the 12" speakers. I guess I said that to say this. You may be stuck with a 100hz (ish) x-over for the K sub, or allow for a big over-lap with the top cabs, but you won't gain any benefit from that, I don't think.

DRA

koshy55

The KSub has a 100 Hz low-pass filter that cannot be adjusted or bypassed -
Bob Lee
Applications Engineer
QSC Audio Products, LLC

Well, That sucks . The KW181 is also like that.

Gadget

I got those specs from the QSC website...I copied those numbers right off the spec sheet... the manual says the same thing, My guess is, the line out of the tops sets a LPF of 100 hz going out to the subs (from the pictures). I think maybe the subs have a natural HPF and are a bandpass sub to begin with.. Simple enough to find out if you have measurement mic, run an auto EQ pass on the subs and see...Perhaps they use a 12dB per octave filter at 100 hz, so what, 10dB down at 148hz, 6dB at 134hz and 4-5 dB @ 130 hz...

If that's the case use a PEQ @ 130hz and boost it 4-5 dB and see if that doesn't do it.. Did you actually talk to him? Did you ask why the manual says otherwise?

koshy55

Well I spoke to the first tech support person, and they said 100 hz. I said then why does it say 134 in the manual and the spec sheet. He transferred my and I got hung up on . I then looked on there forum and saw 100 hz in many locations from moderators.

I have a test mic. I will just need to test it out.

Gadget

There you go... bet they were talking about the 100hz pass through from the tops...

koshy55

yeah, I think im going to call them again. I will also test it day of show with the rta mic.

if it does cross over at 100 hz . I guess I will just cross the srx's at 80 hz, run the K subs at 80-100 and tops at 100 and above. It would be great if the K subs go up to 130hz but with my string of luck lately

either way, Thanks for all the advice and super fast responses

Gadget

Remember, even if they set the LPF @ 100 hz @ 6 dB per octave the signal will only be a couple dB down at most @ 130hz, If it's 12dB only a couple more down, you should be able to use a PEQ in that range and bring that signal back up so it's usable...

koshy55

Remember, even if they set the LPF @ 100 hz @ 6 dB per octave the signal will only be a couple dB down at most @ 130hz, If it's 12dB only a couple more down, you should be able to use a PEQ in that range and bring that signal back up so it's usable

I think I finally spoke to the correct person. and what you state here appears to be correct. It starts to roll off at 100 hz at -9db per octave. So I can boost up the 100 -130 range as you stated. this will allow me to use the ksubs as a mid bass driver. So I can take alot of the low end duty away from the k12's . This is great information to know, thank you for enlighten me

Dra

Gadget, Question for thought.
If the BOX is responsible for roll-off on the high end (because of a bandpass design), can EQ adjustments overcome that? Curious.


DRA

koshy55

The last qsc engineer told me. The box is responsible for the low end roll of and not the high end roll off.
So one could EQ to bring up the high end but not the low end because of the enclosures bandpass.
I am curious as to what gadget's opinoin on this is as well


Should i have the K subs and Kw12's at 0.0 DB gain in the drive rack and the SRX's at -4.3 db gain ( i got this figure from the jbl website )
QSC has no figure on there site to my knowledge

Dra

koshy55 wrote:

Should i have the K subs and Kw12's at 0.0 DB gain in the drive rack and the SRX's at -4.3 db gain ( i got this figure from the jbl website )
QSC has no figure on there site to my knowledge

That -4.3 db spec seems odd. The only way to state something like that is if the top boxes (and quantity) were know and the amp for them and the subs (and quantity) were known.

Dra

koshy55

I got it from http://www.jblpro.com/catalog/general/P ... =118&MId=3 and the the "tunings .zip" I think the last page..

what do you recommend. It seems like one would need to know what amp etc. as you stated.

Gadget

Typical band pass subs have response that goes up to around 200 hz...some lower depending on the internal design.

As for the -4.3.. that number is predicated on using the same amps for the whole rig, and assumes you have the proper amp for speaker.1-2 times the RMS value minimum.

Why not just use the "Start Here" and gain structure to set up the balance. Your only mediocre power wise on the JBLs' but should be enough to get you in trouble if you push it.

koshy55

I re read the Gain structure post. Followed that for setup .

at the venue I ended up changing the crossover setting on the SRX. I settled on a range from 60 hz - 100 hz
Show went great.
Thanks for all the help

Gadget

Cool!