Yet another school sound system proposal

[gotty]

Because of my Beeb background I've been asked by the PTA of a small rural middle school to devise and install a sound system for their hall. The budget is around £2700.

 

I know it's a common topic, and I've read the FAQs and multiple threads, but many are either very old or not totally relevant within the restrictions I'm going to have to consider. So, I hope you don't mind me raising this specific.

 

The hall is 20m x 11m (6m high), with a 5m-deep raised stage behind a prosc arch at the end.

 

It's truly multi-function, being used as for gym (so has wall-bars down both sides), assemblies, discos, ceilidhs, musical performances (from rock to traditional folk), plays and musicals, meetings, presentations, PTA fund-raising events and more. Performances take place on the stage, but also extend well beyond the apron down into the hall itself.

 

The (semi-fixed) installation will have to cope with simple day-to-day needs, such as assemblies with one mic and a CD/DVD input, in a "siwtch on and go" mode. But with some technical help it needs to be able to handle a school musical. The last musical they did had four head-worn radio mics (hired from another school) plus four wired handhelds, an electric piano and CD input for SFX.

 

In terms of mixer sources, I'm taking this (8 mic/mono and 2 stereo sources) as close to the upper limit of what's needed. In terms of power I'm guessing at around 500W.

 

The speakers need to be flexible. For day-to-day stuff they can be mounted either side of the prosc arch, but for events in the hall itself they need to be demounted and put on stands in front of any performers. When there are "whole hall" events (such as a Burns Night supper, where most of the action is in the middle of the hall) I'd probably suggest putting the speakers in diagonally opposite corners.

 

I've heard the Peavey Pro12s and they're where I'm starting from.

 

Because of the lively nature of the hall, I did wonder about reducing the individual speaker power and putting a second set of (fixed) speakers towards the rear. Mounting would be a problem though, and the only practical place would be the rear wall.

 

In terms of mics, they would like at least one hand-held radio mic plus four head-worn radio mics, but with the flexibility to go to lavaliers on the same transmitters if necessary, along with 4 wired mics (probably SM48s) and stands.

 

I did suggest that they just go for a reasonably cheap VHF hand-held radio mic and a VHF headband for everyday use (perhaps Waudio RM-05, which gives extra flexibility since it comes with hand-held, lavalier and headband), then hire-in anything extra that they need. Unfortunately, hire costs are something that they're desperately trying to avoid by using the PTA capital.

 

So I'd like to get them at least two reasonable UHF radio mics with headband/lavalier options (licence cost would not be a problem), which I think would be a good compromise in terms of capital (PTA sourced) and revenue (school budget) expenditure.

 

The mixer is probably the most awkward choice as it has to be reasonably basic and easy to use, but also be flexible (and so much more difficult to use with no technical expertise on site).

 

My first reaction was to go for a powered mixer (something like a Behringer PMP3000, accepting that I'd need to reconsider the speakers). But, while it would be compact and economical and limit the power requirements (which is a real problem in this hall), it is also very complex for everyday use.

 

I wondered if a stereo PA amp with built-in 2 or 3 channel mixer for everyday use, plus a non-powered mixer to supplement it, might be a much better (and more understandable) way to go. If these were mounted in a trolley, with space on top for the bigger mixer, I think it might work.

 

On ancillary stuff, I take points made elsewhere about good quality cables and so on. I don't think we'd go top of the range, but would certainly avoid bargain-basement cables! I may even end up making these (particularly the speaker feeds) myself.

 

The question of a hearing-aid loop has also been raised - and, if there's a bit of money spare (unlikely, but I can hope) I might suggest a Behringer Feedback Destroyer which does seem to work well in its default mode and might save a lot of grief.

 

I've rambled on, and have omitted a lot, but I'd really appreciate some thoughts on the above.

[Matthew Robinson]

I may even end up making these (particularly the speaker feeds) myself.

 

Well, if you plan on making your own speaker feeds, you may as well install them in conduit and install faceplates at the same time. Then get hold of short leads and plug in, from the amp (or output of powered mixer) to the correct inlet plate (because you'd need faceplates everywhere that the speakers would be) and from the outlet plate a short lead to the speaker. That would quite a neat solution.

[Brian]

My first thought was 'what you really want is two mixers'.

 

I suspect that for most of its life the system will be used with just one mic and a CD player. I'd buy a simple £30 mixer, something the Behringer UB502 or its current equivalent and bolt it to the wall at the side of the stage near the light switches. It's about as basic as you can get and coupled with colour coded connectors and a laminated, nailed to the wall, cheat sheet it'll mean anyone will be able to get sound through the system for assemblies/prize givings/etc etc.

[gotty]

may as well install them in conduit and install faceplates at the same time.

 

Good thought, and it'd be ideal, but (due to the highly "non linear" nature of the walls) conduit isn't a practical proposition.

 

A concurrent post has been automatically merged from this point on.

 

My first thought was 'what you really want is two mixers'

That was one of the thoughts that went through my head, but I kept getting diverted by the idea of a powered mixer.

 

Behringer UB502 or its current equivalent and bolt it to the wall at the side of the stage near the light switches. It's about as basic as you can get and coupled with colour coded connectors and a laminated, nailed to the wall, cheat sheet it'll mean anyone will be able to get sound through the system for assemblies/prize givings/etc etc.

Thanks. I think that's a good way to go. It was sort of the way I was thinking when I talked about the PA amp with simple built-in mixer, and perhaps I need to do another recce to see if they could be positioned near the "light switches"

[Andrew C]

If fitting conduit is out of the question, you might consider FP200. It may of course eat all of your budget if you have to pay someone to install cable runs!

 

I too would go for two mixers.

[bruce]

I'd second (or third, or whatever) the "2 mixers" idea. Ideally a lockable wall cabinet somewhere sidestage, with a simple rackable mixer and power amp, radio mic receiver, a couple of hard-wired mic inputs, cd player and input for mp3/ipod.

 

That will cover around 80-90% of the "routine" gigs.

 

For the rare occasion where you need more kit, add a separate mixer (located FoH) and a multicore.

[gotty]

For the rare occasion where you need more kit, add a separate mixer (located FoH) and a multicore.

 

Indeed. Thanks for the thoughts. However, the need for the separate mixer won't necessarily be on rare occasions, and the second mixer could be in use most days of the week.

[Stan Hope-Streeter]

Because of my Beeb background I've been asked by the PTA of a small rural middle school to devise and install a sound system for their hall. ...

 

... I've rambled on, and have omitted a lot, but I'd really appreciate some thoughts on the above.

 

One thing you haven't mentioned is the room acoustics. Do they have any curtains on the walls / over big windows? Does the room sound like the typical multi-purpose hall? In which case any audio will be a nightmare, and lav mics virtually impossible to get usable results from.

You really must include some kind of EQ to allow mics to be rung out before use. An FBX, as you have mentioned, would be useful but only if it is used properly (search other threads on this MB). I don't know how usable the cheap Chinese ones are, having only used the Sabines (out of your budget range).

 

People who control the budgets in these places really need to understand that buying cheap entry level kit is extremely poor value for money compared with hiring in when necessary. Spending hard-fought-for cash on something which is sure to give disappointing results just causes endless grief, and loss of reputation for anyone involved in specifying the kit (probably you).

 

I refuse to get involved in this kind of stuff, for that very reason. I usually just advise putting in some infrastructure (wiring etc) and doing some work on the acoustics - at which point, thankfully, they stop asking me!

[gotty]

Thanks for the thoughts.

 

One thing you haven't mentioned is the room acoustics.

 

I did mention that it was very lively. There are no curtains, but the walls are covered in climbing bars (not much help acoustically of course) and with multiple recesses (which does help). The roof is slightly pitched.

 

Eigentones are surprisingly good (probably due to the irregular walls and the slightly-pitched roof), and although click tests show that reverb is quite bad from some central locations, for wall sources the reverb is limited and surprisingly clean, even when there are no bodies in the hall.

 

Does the room sound like the typical multi-purpose hall?

 

Fortunately not, although it's definitely a bit quirky. With bodies in it, I'm quite surprised at how much better than a typical shoe-box-shaped hall it really is.

 

You really must include some kind of EQ to allow mics to be rung out before use. An FBX, as you have mentioned, would be useful but only if it is used properly (search other threads on this MB). I don't know how usable the cheap Chinese ones are, having only used the Sabines (out of your budget range).

 

I think that EQ is a given, and a Sabine FBX isn't necessarily out of the budget range (although buying the latest model new would be). The Behringer is a good performer, and certainly not a "cheap Chinese one" and is something I'd keep at the back of my mind.

 

As for lavaliers - the stage couples very poorly into (and from) the hall, so they may work quite well there and I mainly mentioned them because some radio mic packages come with them along with head-worn etc. In addition, one group at the school does video work and they'd prove useful there too, not just for hall use.

 

People who control the budgets in these places really need to understand that buying cheap entry level kit is extremely poor value for money compared with hiring in when necessary.

 

I (and they) have to be pragmatic. It'd be wonderful just to hire in as and when needed, but they're already doing this (including calling in favours and assistance from a much bigger school) and it's no longer sustainable in revenue terms. Also, this kit isn't just for one or two gigs a year, but for at least 6 a term. Okay, some of them don't need the full rig, but having the kit would also allow ad hoc use (which is really the driving force behind the whole idea).

 

This certainly doesn't preclude hiring in, of course, and extra items which are needed for specific projects once or twice a year can continue to be hired in as necessary.

 

And putting in infrastructure plus acoustic treatment is simply not an option here.

 

So my original posting was really about trying to make the best technical choices within the given constraints, rather than chaging the constraints. If this was a large senior school doing a couple of major productions a year, the equation would be very different. But it's a small rural middle school, wanting to avoid having to go out and borrow kit every time they put on a class play.

[Stan Hope-Streeter]

Thanks for the thoughts.

........

So my original posting was really about trying to make the best technical choices within the given constraints, rather than chaging the constraints. If this was a large senior school doing a couple of major productions a year, the equation would be very different. But it's a small rural middle school, wanting to avoid having to go out and borrow kit every time they put on a class play.

 

Thanks for all that. I looks like you have things under control, unlike most of the people who post here with similar questions!

 

It also looks like you have a room will plenty of diffusion which helps a lot. Lively but not nasty sounding.

 

If you can get hold of a secondhand Sabine FBX it would probably suit your purpose better than a manual parametric or graphic. Semi-trained operators should be able to follow the setup instructions (it will need setting up and locking off before an event) and are more likely to get it right than by playing around with lots of tweakables that they may not understand.

 

Best of luck.

[Dmills]

Are you allowed to shop second hand (Not always a given in a school)?

 

My thoughts would lean towards spending the lions share on the speakers and to cheap out on the radios (They will get trashed in no time in that environment whatever you do, and anything you can afford will frankly be junk anyway).

You can often pick up something like a pair of PS10 for ~£1000 or so (don't forget the required processing) which are excellent for primarily vocal use, and can always have an additional amp and subs hired in if you need something louder. This will almost certainly be a better long term buy then a whole pile of bottom feeder kit.

Whatever you do, you will want to mount the boxes quite high on the pros arch front to get things reasonably even going back down the hall.

 

It is tempting (if you can make the coverage pattern work) to run with a centre cluster (or even a single speaker) in mono rather then trying to do 'stereo' in this sort of situation, it tends to sound better and the odds are that localisation will not really work anyway. Could you do a single centre speaker at the front over the pros and a second one delayed and flown about half way back?

 

Put a fixed (lockable) rack back stage with the amp and DSP in it (also the radio RXs) with a little "preamp" style mixer (Cloud probably make something usable), you want a couple of wired mic inputs, the radios and a wall plate with phono sockets (DVDs, CDs, IPods... ). Run hardwired speaker ties to next to the wall brackets for the speakers either side of the pros arch at about 12 feet up, and have a pair of speaker patch points by the rack as well. This way there is nothing to fiddle with in the general use case.

 

This way you have something easy used by general staff (Turn on the red switch, plug the mic into the yellow socket, turn up the yellow knob), and for the once in a blue moon musical (when you need more inputs and more processing), you do the hire or borrow thing.

 

Regards, Dan.

[dbuckley]

My local schools "GP hall" is a multi-purpose thing that does everything that you mention; they have not one but two sound systems, an installed thing which does 90% of the work, its a little mixer, CD/Cassette machine, a (mediocre) radio mic, a couple of wired mics, and permanent wall mounted speakers along with a QSC amp. For the stuff it does, its perfectly adequate, being sufficiently loud and intelligible.

 

For eventy stuff they drag out an A&H powered mixer and a couple of big JBL boxes, and the multicore.

 

The "big rig" can also travel to other venues as required.

[gotty]

Thanks for all that. I looks like you have things under control, unlike most of the people who post here with similar questions!

 

That's possibly because of nearly 40 years in the audio/broadcast business, and having some experience of a lot of major installations (from hall systems to continuities) at the BBC.

 

... better than a manual parametric or graphic

 

I definitely wouldn't go there for this sort of installation. But the Behringer Feedback Destroyer does much the same as the Sabine, but is more affordable and, from what I've seen, is fairly easy to "train" and then lock off.

 

Thanks for the thoughts.

 

A concurrent post has been automatically merged from this point on.

 

Are you allowed to shop second hand (Not always a given in a school)?

 

In theory, yes, but they'd need some warranty cover.

 

are excellent for primarily vocal use

 

I think this is where there may be some problems in that "excellent" is not within the concept. "Good" will be adequate.

 

It is tempting (if you can make the coverage pattern work) to run with a centre cluster (or even a single speaker) in mono

 

Stereo imaging isn't too bad, and the school wants to be able to be able to use the kit for DVD movies. So stereo is what is wanted. In addition, feeding into the hall hight at the centre may have some strange acoustics.

 

Put a fixed (lockable) rack back stage with the amp and DSP in it (also the radio RXs) with a little "preamp" style mixer (Cloud probably make something usable), you want a couple of wired mic inputs, the radios and a wall plate with phono sockets (DVDs, CDs, IPods... ). Run hardwired speaker ties to next to the wall brackets for the speakers either side of the pros arch at about 12 feet up, and have a pair of speaker patch points by the rack as well. This way there is nothing to fiddle with in the general use case.

 

I think that's where I'm heading.

 

he once in a blue moon musical (when you need more inputs and more processing), you do the hire or borrow thing.

 

Unfortunately, events needing more inputs/processing are not "once in a blue moon", which is really the point of the exercise.

 

Thanks for the thoughts.

[revbobuk]

A comment on a different aspect. I've used (and even installed - won't do it again) some of the cheap W-audio style radio mics. The Kam dual radio is (just) acceptable when used as a handheld. The lav and the headworn are utter rubbish. I now won't go any cheaper than the Trantec s4.4 series, even given the really harsh environment of a school. At least with the Trantec I can use Pulse capsules or headsets from CPC, and the handheld is (IMO) very good - doesn't drop out, and has very little switch on/off clicking. The receiver is quiet when there's no carrier, which means the users can control it themselves if that is required, and the switch is solid. I wouldn't go too cheap on the radios!

[Munro]

we have four AKG cheap mics at my school (god knows what model, just the cheap as chips one) and although they are not the best, they satisfy the school well enough. when they bought them, I cant have seen them paying anymore than £200 for each one.

 

But of course, I dont like them, cos im a perfectionist. But before I was there they all thought they were the bees knees. :-D

That was until I showed them a Sennheiser SK500. The AKGs are now reserved for assemblies. any other time, we just hire Sennheisers in from Wigwam.