How to set up a missmatched system

jthunderbass

I felt the need to creat this post after setting up yesterday afternoon.
Next Saturday I am doing sound for a recent rock and roll hall of fame inducty. He is the keyboard player for that band that the lead singer didnt show up for the awards and induction. :?
Yesterday we set up a sound system that we will be using for the concert. The system is basicly 3 differnt brands of speakers all in one to creat a very very loud monster!!!
We are using a Yamaha analog board, into DBX EQ, and then into the Driverack PA, then into QCS 3600 watt amps, powering, 2 JBL 3 way tops, 2 Cerwin Vega single 18 subs, and 2 EV Eliminator single 18 subs. We are trippling the power like we shoudl be.
The reason why I felt the need to write this thread is for anyone out there with a setup similar to this, where you are using missmatched speakers. WHat I did was I ran the system stereo 3 way. WHat I did differantly was... Instead of doing Low, Mid, and High outputs. I did Low, Low, High.
I put the EV's on the Low output and ran the xover somthing like 45-100hz, Cerwin Vegas something like 30-160hz and the JBLs at a few hz above the cerwin vegas.
THe reason why I did this is so that I could set indevidual crossover slopes per speaker, and also differnt frequency regions for the speakers.
One problem we had was after setting gain and doing the auto eq outdoors, the system was very very harsh, then I realised, I didnt have the compressor on. I set it to 1.9:1 -10 for the threshold and about -3 db as the output. I thnk I may need a heavier compression setting for the JBLs.
Now some of those numbers might be a little off, the whole point of the thread is to show how to set up a miss matched system usaing a Driverack PA.
I do need to set delays on the subs though.
End result was I could hear the music 1/2 mile away, faintly, very very loud and very clear sounding up close. It was a bit honky, buit thats JBL for you. I will have to do some tweeking when we set the system up indoors. I have to get rid of that mid range sound and the honk.
Well have fun. I have to load in 2 shows, in 2 differnt locations, with 2 differnt bandsd this afternoon. 5 shows this weekend!!! Ill be using the Driverack for 4 of them!!!

jthunderbass

Very Very loud!!!!

Dra

Have you considered splitting the four subs into upper and lower range subs? You would lose air mass, but the the inherent problems of mixing sub types could be a bigger problem. Which would play which role would take some experimenting, but the process would be pretty simple. The horn might do best in the 70 to 120 range, but.... it is a thought.

If I were doing this gig with a "national act", I'd paint over (or at least cover in some way) the giant Cerwin Vega. Deserved or not, it screams "DJ gear" and "look at me I'm loud".

DRA

Gadget

WHAT IN THE WORLD ARE YOU DOING? :shock: :shock: :shock:

I have to recommend DON"T DO THIS!

Look JT your NOT likely to make it through the weekend...not without damaging something... like the horns on the JBL's...here's whats wrong...

Horn loaded subs above 120 hz = HONK

Dissimilar subs covering the same frequency range = comb filtering, cancellations and general sonic chaos...

Using the compressor for removing harshness = are you kidding me? What your doing is squashing the high's with the comp and increasing the duty cycle of the horns...

I wasn't even going to post, but seriously you can't be giving out that kind of advise.. it's just wrong!

One more time...here's a more sonically correct approach.

Cerwin subs: 30-50hz 30hz BW18 to 50HZ LR24
EV subs 50-118hz LR24 both HPF and LPF
JBL's 118hz >out LR 24 slope (could go as low as 100 hz but won't get as loud without damage)

Use the PEQ's to get rid of the harshness (what did the Auto EQ show for the HF harsh points?)
Use the PEQ's to tame the mid buildup
JBL's are KNOWN for harshness... those look like SR4732a's if I'm not mistaken, and were a staple of the industry for many years. Capable of getting quite loud, but are you telling us you are driving them with 3600 watts? That's bit much... you better be careful...

jthunderbass

:oops: :oops: :oops: :oops: :oops: :oops: :oops: :oops:
Dra: The reason I did the horn loaded subs higher was to get the upper and lower bass effect that you were talking about, but like Gadget siad I went wrong by running both subs in the same frequency range.

Gadget: The HF harsh point were 12.5k, 10k, 8k, 5k, 4k, 3.15k, 1k. I may heve a few mid frequencies in there too. I absolutly agree that JBL is very very honky. These are the only JBL speakers that I have heard that sound ok.
I still prefer my Emmenance loaded Sound Techs because of the huge fat sound they have. I cannot wait to get started on those LABsubs.
One othewr thing before I forget. We are bridging the amps for the JBLs.

Gadget

What exactly do you mean by:

The HF harsh point were 12.5k, 10k, 8k, 5k, 4k, 3.15k, 1k.

Where did you come up with that? Is that an Auto EQ product? if so perhaps you could take a picture of the auto eq pass results in the GEQ?

Also, if this was an Auto EQ result, what exactly did you do to get those results (setup)

Those are probably my favorite JBL speakers in the SR series..(as JBL speakers go) I was talking to Sonny, and old partner here from the past today, and he has them and doesn't have to do a whole bunch of eq to get a decent sound out of them. he has, in recent years updated the 12" woofers to DAS drivers, but that is another story...