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[Al Dearden]

Hi folks,

Wonder if i could have some opinions about the merits or otherwise of "flying" powered cabs in a Church hall.

The present arrangement of passive/unpowerd speakers + amp is due for replacement. Powered speakers (Makie 450 or similar) are suggested. There are obvious issues relating to the added weight of the replacements but assuming these can be overcome by instalation of the correct brackets etc. I was wondering about issues with power supplies and need to switch on/off via the mains supply rather than with the provided on-cab switches.

Are there any other considerations we should be aware of?

My own preferences would be for passive speakers with a suitable power amp and basically just swap-out the existing boxes but finances are limited the Mackies are "recommended" and perhaps more importantly are available at a significant discount at the moment.

Running on tripod stands would not be an option, and there are significant difficulties (not least costs) in installing a gantry type suspension system to place the speakers centrally. They would (I think) have to be wall mounted on L+R side walls of the building.

Main use is for worship services (voice and "band" instruments)with the occasional "concert-type" event.

Thanks in anticipation.

[Ira White]

Though there are a lot of good posts here on powered speakers and they do offer some optimum amp/processor matching out of the box, I'm not crazy about using them in installed/flying applications. I believe concerns for weight, maintenance, and having to provide additional power to their locations (especially for multi-point systems) are major.

I like the idea of having amplification where I can get to it for tackling electronic problems, and a single speaker cable run to the cabinet. I also find it more economical to purchase a single amp and processor that can drive at least four matched speakers than buying four separate amplifiers in the enclosures themselves. Just my opinion.

[Brad Weber]

Al Dearden wrote on Mon, 11 December 2006 07:22

Powered speakers (Makie 450 or similar) are suggested.

Quote:

My own preferences would be for passive speakers with a suitable power amp and basically just swap-out the existing boxes but finances are limited the Mackies are "recommended" and perhaps more importantly are available at a significant discount at the moment.

Let's turn this around.  Who is recommending powered speakers and, other than the discounted cost, what reasons are given for recommending the powered speakers?

Powered speakers certainly do have some benefits and work very well in some applications.  However, simple retrofits of existing speakers is not usually one of those situations.  You are obviously aware of some of the issues and Ira has already addressed many of as well.

You haven't mentioned what speakers, amplification and processing you currently have or anything about the room or arrangement or even if the speaker replacement is part of an overall upgrade, but it you already have speaker processing, power for amps at racks, etc., then powered speakers may not only require additional cost due to their own weight and power requirements, but also may not take advantage of your existing power provisions and cabling.

However, probably the most important point to make is that you need to select speakers based on their being appropriate for your specific application.  Aspects including coverage, output levels and frequency response need to be considered as to the requirements for your specific application and selecting speakers should be based on their meeting those criteria.

[Tom Young]

In the interest of clarity and technical correctness:

In a properly designed and then optimized system you will not have 4 loudspeakers in the primary arrays/clusters that are symetrical/equal in their coverage areas. 2 is pretty much the maximum and these would have to be in a center cluster in a symetrical room (for there to be symetrical coverage and therefore on the same DSP).

So you will need more than one amp channel and DSP output.

The exception would be for delay fills, where there *could be* more than 2 devices on the same amp and DSP. But this also depends on architecure and mounting positions.

[Michael King]

not to mention most of the powered speakers you will find at "discount" prices are not going to come with fly points. So i couldn't recommend flying any speakers not made to be. Its a situation where safety should come first.

[Tom Young]

I am an advocate for selfpowered loudspeakers, but only under the right conditions.

As mentioned; you will need to structurally accommodate the additional weight. Employing the word "brackets" sort of hints at an underappreciation for proper rigging design and hardware. As you will glean from reading replies here at this site over the years, it is mandatory that a licensed professional engineer (with rigging experience) either design the rigging system or review the design. Once the system has been installed, the same licensed professional must inspect the installation and then provide you with stamped documents stating that the rigging system (and this includes the building structure) is safe. There is no way around this and it applies to any ldspkr system, passive or selfpowered. It does not necessarily cost a whole lot.

Also as mentioned (but I will elaborate); you need the proper amount of AC circuits at the selfpowered loudspeaker positions. You can probably power 2-3 selfpowered fullrange (2-way) ldspkrs off a single 20A circuit, but this can only be determined through careful consideration of maximum current draw for each device.

You then need a remote controlled sequential AC power system so that you can power down (and up) the entire system in a non-destructive manner.

These electrical systems can only be installed by a licensed electrical contractor and they may need to be inspected, as well.

If the above advice is taken it will very likely discourage you (or whomever advocated this) from following the selfpowered route. That was not my intent, but reality is reality.

Just be aware that (as Brad and Ira point out) in almost all cases a selfpowered system provides optimal performance as a result of proper amplifier, driver and crossover matching plus electronic alignment and inter-ldspkr equalization. And (typically) at a lower cost. In going the passive route, much more optimization work is required following the installation. But in either case there is a need for this optimization.

Given your situation I also recommend that you go the passive route. But I strongly recommend that you have someone come in and measure and optimize the system once it has been installed.
This makes all the difference in the world in how an installed loudspeaker system performs.

And (again) I also strongly recommend that you have the system professionally rigged.

[Ira White]

"In a properly designed and then optimized system you will not have 4 loudspeakers in the primary arrays/clusters that are symetrical/equal in their coverage areas. 2 is pretty much the maximum..."

Yes, I was thinking of two speakers on each side of a standard dual-channel amp: two for center coverage, two for side, or some practical variation. Still "one" amp package for the four.

[ProSoundWeb Community]