ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: Front Fill and Delay speaker setup  (Read 1664 times)

Alex Pregel

  • Newbie
  • *
  • Offline Offline
  • Posts: 5
Front Fill and Delay speaker setup
« on: January 07, 2017, 10:00:50 pm »

Hello, I am a current High School senior and am having trouble figuring out how to really setup and calibrate/process front fill and balcony delay speakers. I have some background knowledge in some basic concepts  (thanks to Bob McCarthy's book). From what I gathered the most important thing in front fills is phase alignment at the crossover point with the mains where both systems are at -6db. First of all, is this the right concept for these and how do I go about accomplishing this? In the past we just threw the delays up and measured (length) at the estimated crossover point for the delay with a little EQ. While this sounded ok I would like to figure out how to take a lot of the guess work out if it. A little background in the space... [it's a 850 seat percenium style theater with a bowed out pit. The mains are a center JBL VRX line array with a flown sub and three boxes. I've been using four small speakers as the full (not sure if the model) but they have about a 90 degree conical pattern and sit at the edge of the pit at about 30 feet from the main speakers. Currently the HF from the mains drops out by the 3rd row and the 1st row is always unused since it is so close to the fills and the pit.] So, I currently just have a behringer calibration mic at my disposal and the free room EQ wizard and a two input interface. We are running the system from a Yamaha QL5. I can also get the free trail of Smaart if needed. So, how would I go about finding the crossover point and align the phase with two speakers that have very different phase and frequency responses? Moving on to the balcony. The first row is about 80 feet from the mains. At this point do I need to worry about combing or just go with the measured delay with a bit more for the Haas effect and EQ or do I still need to figure out the phase relationship? Please let me know any knowledge you can pass on!
Logged

Merlijn van Veen

  • Moderator
  • Sr. Member
  • *****
  • Offline Offline
  • Posts: 293
    • www.merlijnvanveen.nl
Re: Front Fill and Delay speaker setup
« Reply #1 on: January 08, 2017, 08:31:11 am »

Delay times are best set at positions where systems meet eye to eye at the same level. This is where interaction will be worst (joint custody).

  • Commit to a target curve ONAX to the main system solo.
  • Make each sub-system in their respective zones solo match the target curve in level AND tonality. This includes accounting for HF losses by air. Otherwise e.g. front fills will end up sounding like bacon fills (pun intended).
  • Impulse response is your friend when hunting for the equal loudness position. With both systems you're trying to align turned on, look for the position where both IR's have equal magnitude by moving the microphone in the area of joint custody. This is typically the imaginary line connecting the ONAX positions. Initially center your delay locator between both IR's manually. For a clearer view, when time offsets are already small to begin with, it helps to add a small amount of delay e.g. 5 to 10 ms on purpose in order to separate the IR's further apart.
  • Once the position of equal loudness has been found, verify your levels in the transfer function magnitude response and tweak the mic position when necessary. Add the time offset between the IR's to the system that's leading taking into account the additional delay that might have been used in the previous step
  • For good measure, shelve or even cut surplus LF typically bleeding from the main system into the fill zones in each sub-system respectively.

Regards,

Merlijn
« Last Edit: January 08, 2017, 08:48:45 am by Merlijn van Veen »
Logged

Alex Pregel

  • Newbie
  • *
  • Offline Offline
  • Posts: 5
Re: Front Fill and Delay speaker setup
« Reply #2 on: January 08, 2017, 09:59:25 am »

Thanks so much for you help! On step two you mention matching the two sub systems in level and tonality at the ONAX position. Here what do you mean account for HF losss? The mains are already heavily controlled through a Biamp processing system so I would prefer not to change anything there. So am I just matching the measurements on the ONAX point of each solo system separately by changing the level and adding EQ? Also in the last step would I just place the microphone at the ONAX of the front fills, turn both systems on, and use the FFT reading and apply some EQ (just to the FF) to the effected LF response of the two summed systems?
Logged

Ivan Beaver

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8176
  • Atlanta GA
Re: Front Fill and Delay speaker setup
« Reply #3 on: January 08, 2017, 10:12:02 am »

First of all FORGET about getting a good phase alignment between fills and delays (or any other 2 sets of speakers that are in physically different places.

Sure, you can get it in ONE seat, but move a few seats to the side and now it all falls apart. 

I just want to add some "delay speaker" thoughts that many people don't often address.

And that is consider what is happening COMPLETELY OUT of the coverage pattern of the delay speakers.

Lets say the delays are covering a balcony.  Once you have the delay time set, there are other considerations.  Freq response and level. 

So let's assume you have the response and level "just right" for the balcony.

HOWEVER-what about the seats ON THE MAIN FLOOR?

Unless the delay speaker has a LARGE FULL RANGE horn, there will be spillage onto the main floor.

So now you have screwed up the response there.

And sometimes people on the floor will "hear" the delay speakers and get some sort of "pulling of image" up to them-which makes it harder to enjoy the performance.

SO now comes the "balancing act".  I will not go into a lot of details here, but often you have to drop the level of the delay speakers (so they are not heard as loud on the floor). 

Sometimes you will have to raise the highpass filter so the lower freq out of the delay are not as loud on the seats below.

Yes the level and response may not be exactly what you want-but now BOTH sections are overall better.

You MUST continue to listen to the different seats in a room whenever you have more than one speaker for the damage the other speakers are doing to the coverage area of the main speaker.

That is why I love the multi mic setup, it allows you to put mics in different places and monitor what is going on all at the same time, so you can actually "see" what effect one speaker has on anothers coverage area.

Logged
A complex question is easily answered by a simple-easy to understand WRONG answer!

Ivan Beaver
Danley Sound Labs

PHYSICS- NOT FADS!

Merlijn van Veen

  • Moderator
  • Sr. Member
  • *****
  • Offline Offline
  • Posts: 293
    • www.merlijnvanveen.nl
Re: Front Fill and Delay speaker setup
« Reply #4 on: January 08, 2017, 11:38:30 am »

Thanks so much for you help! On step two you mention matching the two sub systems in level and tonality at the ONAX position. Here what do you mean account for HF losss? The mains are already heavily controlled through a Biamp processing system so I would prefer not to change anything there. So am I just matching the measurements on the ONAX point of each solo system separately by changing the level and adding EQ? Also in the last step would I just place the microphone at the ONAX of the front fills, turn both systems on, and use the FFT reading and apply some EQ (just to the FF) to the effected LF response of the two summed systems?

I assume you want the people that reside in the sole custody of the front fills (typically MF and HF) to experience the same sound as the audience covered by the main PA? If so, they need to operate at the same level (or add until front fill and main PA operate at the same level in joint effort) and sound the same. Your front fills are likely to have suffered only from a few meters of air in contrast to the main PA which has likely crossed dozens of meters. The latter is therefor typically darker which leaves you two options. You either make your front fills equally dark as well or your main PA brighter by means of EQ.

In step 5 of my recipe, I meant appropriately shelving or cutting LF in the front fills to account for the excess lows typically spilling from the main PA because it has little to no directional control in the bottom end. It can't steer clear from the first couple of rows. Same goes for subs on the floor. This can be done using the analyzer but is just as easily adjusted by ear. Get rid of those frequencies where there are to much of.

Logged

Alex Pregel

  • Newbie
  • *
  • Offline Offline
  • Posts: 5
Re: Front Fill and Delay speaker setup
« Reply #5 on: January 08, 2017, 11:53:55 am »

Thanks for the clarification!
Logged
Pages: [1]   Go Up
 


Page created in 0.114 seconds with 23 queries.