Editor’s Note: Here’s an interesting thread from the PSW Church Sound forums. It’s lightly edited for grammar and formatting. Enjoy.
Posted by Steven
Before I started attending my current church, they were already in the process of having the PA replaced. They had decided to use a local live event production company that had done several small to medium-sized installs but had limited experience with a job this size. Through consultations with EV, and based on their design recommendation, the system he installed was a line array, which I think was probably the right choice.
The problem is that the installer doesn’t have the tools or experience to optimize the system past a basic RTA reading of the room. We are satisfied that the equipment we have is what we need, but we need someone to come in with SMAART or other advanced software, and set crossover frequencies and slopes, EQ, and whatever other settings are necessary to optimize the system.
Would an A/V integrator be the person or company we are looking for? An acoustics engineer? An engineer from the manufacturer? Someone else?
Reply by Ivan
There are lots of independent people who can “tune” a system. But here is the problem…
What happens if they get there, and the cabinets are not hung properly? ie the angles between the cabinets, the position of the array, etc. Electrical adjustment can only do so much, but if the install is not properly done, there could still be coverage issues.
Often people don’t want to be responsible for others’ work. You can end up with awkward situations such the “tuner” says the hang isn’t correct, and the installer says the “tuner” doesn’t know what he is doing. And it could either one or a combination of both.
I have met quite a few “tuners” who can talk a good game but don’t really have a good measurement foundation. I have also seen installations in which I say to myself “WHAT were they thinking?”
In my opinion, it is the responsibility of the person selling the job/installing the job to ensure that it is covering properly and working properly.
Reply by Jerome
Speakers that have overlaps in coverage can cause comb filters, peaks, and dips in response based on frequencies and distance. Does your speaker have specifications showing 90 degree x 40 degree horns? Do these horns patterns of 90-degree overlap? Do they cover the area of seating well?
Then, is there enough power to have the desired level at the back?
The 40 degree is vertical usually and should be in the front to back reach.
The RTA or Smart programs will help with the low frequency to high-frequency balance. Are they equal and appropriate?
Acoustics problems like reverb and echo can be a problem with understanding the spoken word. This is a design and building issue that’s not easily corrected because it will need construction changes. Very rarely will acoustic panels help in reducing that. Acoustic panels with directional speakers placed to keep sound off the walls or boundaries combined can improve the problem to a degree.
Reply by Stephan
What are the problems you feel need correcting? There are those, even on here, that might be willing to help (for a fee) make a bad situation as good as possible-but as this is presented, it is a loaded situation most would not want to walk into.
How do you know the installer does not have the correct tools? Crossovers would likely be primarily a design concern that should already have been addressed by consultation with the manufacturer.
As others have said, not everything can be fixed by electronics. Unless you can define what’s broke, a solution is impossible. It may well be that any deficiencies you are hearing are room issues that cannot be fixed by “tuning.”
Our church rented a venue a week ago. My pastor was amazed by the sound and asked: “Why can’t I get this?”
Biggest difference? That is a 2-year-old building built as a performing arts center-not a reflecting surface in sight, ours was built during the Civil War to enhance unamplified sound. Electronics will never make the 2 sound the same, no matter how much tuning is done. That is an extreme example-there is a lot of in-between territories that most churches fall in to.
Reply by Steven
Yup, I totally agree with you. Unfortunately, I don’t think we’ll get what we’re looking for by going back to the installer. First, it’s been over a year since it was installed, and second, he’ll probably come back in with his RTA, make a few tweaks, and call it good. Like I said, this decision was made before I was here. I’m just wondering who to call now to get it done properly as properly as possible.
As far as what can be done, there’s nothing stopping us from changing the angle between the boxes. Turning the array would be more of a challenge, but not impossible.
I realize it’s not a good situation to put someone into, and I know there’s only so much we can do with it as installed, I’m just looking for the person to get what’s possible out of this rig.
Reply by Jonathan
I’ll just point out that any two or more speakers fed the same program material in the same room WILL have overlaps in coverage, regardless of their relative angles. The question is, “at what frequency?”
Proper aiming and tuning won’t eliminate the overlaps. It will put the overlaps where it is less likely to matter — like in the aisles.
Of course, knowing that doesn’t solve the immediate problem of finding competent help, but competent help with the right tools will understand the problem and be able to optimize the system.