ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: Implementing front fills  (Read 6169 times)

Dan Johnson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 223
Implementing front fills
« on: December 14, 2008, 02:09:15 am »

I run sound for an independent Christian rock band.  We do a small number of local gigs and we travel some throughout the year.  We play a wide variety of venues from 100-200 seat church youth rooms to 6000 seat venues.  All the bigger events have major production provided and we bring our own sound for 95% of the smaller events.  While I fancy myself a decent BE, I'm certainly not very experienced as an SE.  I know how to make our system sound good but don't have much experience at all setting up any other systems.  I'm in the process of doing some minor upgrades to our current system.  I want to make sure I'm doing things right the first time instead of implementing something and then finding out later I've been doing it wrong (or missing some key element) all along.

I'm thinking about adding front fills to our system and I've never had to deal with this before.  It seems like every gig we do lately, a portion of the audience is standing right in front of the stage out of the coverage of the mains.  The other issue is when we play a big enough room that the speaker stacks are spread apart enough that I need a little more support (mainly vocals) in the first couple rows right in the center.  It seems like we are most often playing stages that are only 2' tall or it's the typical church stage where the entire front of the stage is steps from the floor to the stage which is roughly 4' above the floor.  

I'm wondering if I should be too concerned about the horn coverage pattern on the front fills or if it doesn't make that much difference.  I read through some old threads and saw recommendations for front fills with a wide variety of coverage patterns.  I don't want to create any cancellation because of overlapping patterns with the main speakers.  This wouldn't be much of an issue with a 2' tall stage with people standing right in front of the fills but maybe would be a problem in other situations.  

I was thinking of the possibility of using stage monitors for the front fill if I didn't need a tighter coverage pattern.  This would allow me to easily aim them up when we are on the short stage with people right in front of them.  I could make some wedges to aim them more straight out on a taller stage.  Is there any reason I'm not thinking of that this would be a bad idea?

The other thing I was wondering about was whether I should be worried about time alignment issues between the mains and front fills for the situations where the audience isn't standing right in front of the fills.  Any advice on this?  Any insight you guys can give is appreciated.
Logged

Tom Young

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2620
Re: Implementing front fills
« Reply #1 on: December 14, 2008, 07:17:04 am »

First of all: these are very good questions. I applaud your observational and communication skills.

"I'm wondering if I should be too concerned about the horn coverage pattern on the front fills or if it doesn't make that much difference. I read through some old threads and saw recommendations for front fills with a wide variety of coverage patterns. I don't want to create any cancellation because of overlapping patterns with the main speakers. This wouldn't be much of an issue with a 2' tall stage with people standing right in front of the fills but maybe would be a problem in other situations."

There are a few things that are inherent with front fills:
They usually are not run as loud as the mains because they are so close to the target listeners. The acoustic energy from front fills is also usually absorbed by these folks (so the sound does not throw that far). And they are so small that the pattern control provided by the HF horn does not extend very far down in frequency. That being said; you do want fairly wide coverage which equates to a need for fewer front fill devices.

"I was thinking of the possibility of using stage monitors for the front fill if I didn't need a tighter coverage pattern. This would allow me to easily aim them up when we are on the short stage with people right in front of them. I could make some wedges to aim them more straight out on a taller stage. Is there any reason I'm not thinking of that this would be a bad idea?"

Not that I can think of (*). Most, if not all, "purpose-built" fill loudspeakers will have a smaller footprint but in your case the visibility of these fill devices is not as great an issue as it is in concert halls or may be in pristine/traditional style worship spaces. Using monitors (as you point out) allows you to aim them dead ahead or slightly upwards.... as needed. Many wedges can fire directly ahead without the need for an additional wedge/shim to prop them up. Plus you may need these extra wedges as back up for (monitor) wedge duty.

Actually, I can think of a few "gotcha's" to watch out for: You need to make sure that the wedges you use can be oriented so the wider coverage pattern is along the horizontal axis. Purpose-built front fills will provide 90-120 degree horizontal coverage. Wedges tend to be in the 60-90 degree range - no wider. So you may need 1-2 more wedges for front fill duty (in some venues) than you would if you had "real" front fills.

"The other thing I was wondering about was whether I should be worried about time alignment issues between the mains and front fills for the situations where the audience isn't standing right in front of the fills. Any advice on this? Any insight you guys can give is appreciated."

Yes - you should be concerned with alignment. Front fills will be out of alignment to the main FOH speakers (the LF energy from these will be covering in that front area even if the HF's are not) so the front fills will benefit by being delayed a bit. But they will also be out of alignment to the louder sources on stage (drums, loud wedges, etc) and the front row listeners are close enough that the energy from these on-stage sources will often be plenty audible. So if you apply a delay to the front fills you can align them (or get them closer to being aligned) to both of these later-arriving signals.

Front fills also need a high-pass filter because they cannot handle LF's as well as the larger main FOH ldspkrs. Plus you do not need to introduce more LF energy into that area, you already will have enough from the FOH. And they very definitley need equalization to smooth out their response. This is especially useful/necessary if the singers (or a pastor with a lav mic) lean over the front fills or walk out in front of them.

These days it is hard to buy a DSP that does not provide all of these processing functions. Take advantage of them.
Logged
Tom Young
Electroacoustic Design Services
Oxford CT
Tel: 203.888.6217
Email: dbspl@earthlink.net
www.dbspl.com

Mike Caldwell

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 943
    • http://www.mikecaldwellaudioproductions.com
Re: Implementing front fills
« Reply #2 on: December 14, 2008, 10:23:44 am »

If your board has an open post fade aux or a matrix mix that would be the best way to feed the front fills. You will be able to build a front fill mix independent of the main mix. The same thing goes for a rear delay fill mix as well.

Mike Caldwell

Rick Stansby

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2401
Re: Implementing front fills
« Reply #3 on: December 14, 2008, 11:03:56 am »

I agree with Tom, especially the part about your very good understanding of what is necessary, and what pitfalls you might encounter.

I have regularly used monitors as front fills, especially when the band has IEMs, so the monitors are unused and the stage wash doesn't include much vocal.  Usually the monitor needs to be set on end, to get a wide horizontal coverage.  This can be an issue with sight-lines or a clean look.  

Wide coverage is your friend, so you don't need too many fills, and so the sound doesn't project too far.  When using more narrow boxes (70 to 90 degrees) I have put them at the outside corners of the stage (near the mains) facing in towards the center of the front few rows.  This will also solve the problem with delay, in the case that you don't have the processing available.

As has been mentioned you will mainly want vocals and quiet/non-amplified instruments in the front fills.  You probably realize that you won't need a bunch of drums, bass or electric guitar.  They are loud enough in the front row.
Logged
Rick

Lee Douglas

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 381
Re: Implementing front fills
« Reply #4 on: December 14, 2008, 01:17:59 pm »

Dan Johnson wrote on Sat, 13 December 2008 23:09



It seems like we are most often playing stages that are only 2' tall or it's the typical church stage where the entire front of the stage is steps from the floor to the stage which is roughly 4' above the floor.  




I don't know the answer, but it would seem to me that a front fill on a two foot stage with people crowded up against might have a usable sound for maybe four or five people crowded together across and possibly two deep with a wide dispersion pattern and nominally more for a four foot stage.  Something on the front light truss might have better coverage maybe?  Or would you just provide multiple fills across the front of the stage?
Logged
My life has a superb cast but I can't figure out the plot...

Dan Johnson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 223
Re: Implementing front fills
« Reply #5 on: December 14, 2008, 05:55:00 pm »

Thanks for the great response Tom.  You pretty much touched on most of the things I had been thinking through already.  Would you say that vertical dispersion pattern would be a big concern?  I would think it may be more so when we are on the shorter stage with the front fills angled up (because of vocal mics on stage) but at least we're not typically dealing with reflections off of low ceilings.  And maybe not as much an issue when firing straight forward.  I've already got all of the tools to do this except for the actual speakers so I would be getting something specifically for this purpose.  I'm thinking more towards dedicated front fills rather than monitors after reading the responses.  I can always angle the front fills up as opposed to angling monitors straight forwards.
Logged

Dan Johnson

  • Full Member
  • ***
  • Offline Offline
  • Posts: 223
Re: Implementing front fills
« Reply #6 on: December 14, 2008, 05:57:48 pm »

Lee Douglas wrote on Sun, 14 December 2008 12:17

it would seem to me that a front fill on a two foot stage with people crowded up against might have a usable sound for maybe four or five people crowded together across and possibly two deep with a wide dispersion pattern and nominally more for a four foot stage.  Something on the front light truss might have better coverage maybe?  Or would you just provide multiple fills across the front of the stage?

These 2' tall stages are usually not all that wide and I was thinking multiple fills for these situations for the very reasons you suggested.  It may not be a perfect solution but it would be better than nothing for sure.
Logged

Tom Young

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2620
Re: Implementing front fills
« Reply #7 on: December 14, 2008, 07:52:42 pm »

"Would you say that vertical dispersion pattern would be a big concern?"

Sure. But this is not quite as important as horizontal coverage, which determines how many devices you will need. If you get crowds that are so close that they are above the vertical coverage (partly because you have such low platform/stage heights) chances are pretty good they will be blocking the HF's from everyone behind them. So at that point it matters little whether you have medium or wide vertical coverage.

I would shoot for something in the range of 90-120 degrees H x 60-70 degrees V.

EAW, EV, Meyer, Renkus Heinz, JBL, Yamaha Commercial and a few others make decent to very good front fills (sometimes billed as "underbalcony" loudspeakers). Some of these have an angled side as well as a right-angle side, which would provide you with more flexibility.

You should also consider getting front fills that are the same make (and even same series, or line) as your FOH ldspkrs. Doing so means they are more likely to sound like the FOH. To some degree, anyways.
Logged
Tom Young
Electroacoustic Design Services
Oxford CT
Tel: 203.888.6217
Email: dbspl@earthlink.net
www.dbspl.com
Pages: [1]   Go Up
 


Page created in 0.08 seconds with 23 queries.