J Pearce

The XL4 left last year, to a good home wanting to refurb it and feed it multitracks on occasion. Still got plenty of other old stuff kicking about, but the XL4 was taking up a lot more space than we could justify. We did power it up one last time before it departed, having located 6 sturdy crew to be able to lift it and tip it. It told us to call Midas service dept - we were rather tempted to!

That's a very odd system and if we had anything like a functioning trading standards system it wouldn't be for sale. PMR is in 446MHz, so they wouldn't fall under PMR. PMSE might issue a spot frequency license, but you'd need to ask. We have some spot frequencies in the 500MHz band at work. I think they probably cost similar to the purchase cost of the unit you link to, which is nearly always the result of buying cheap gear - it costs more to run. Do you know that they actually run on those frequencies, or are you trusting the labelling on a bit of kit already known to be of somewhat suspect origin? I have a cheap(ish) spectrum analyser that is handy for this sort of thing.

Pallet shipping can work well. Lots of couriers aren't used to handling our sort of loads, so either arrange loading/unloading at either end or standardise and put it all on pallets. Also, design your set construction with transport in mind. Do continue to ask around, as you may find someone willing to van share - but as cautioned above, don't be tempted to overload a van, there are 'rolling weighbridges' on multiple routes between London and Edinburgh.

For what a MAC600 did, you'd probably do just as well to remove most of the innards inside the head, mount a RGBW LED PAR at the front where the lens used to be and use the mover shell as a cheap version of an Apollo RightArm. Bonus points for a zoomable LED PAR.

Goodness, I hadn't heard. A lovely chap with a big grin and a mischevious streak on the few shows I worked with him. Sending love to all who knew him.

Artistic License also have some options, which I've only seen at a tradeshow, but looked good. At the upper end of the price bracket ETC have what was GDS's system.

Cat5 cable is explicitly stated as compliant in the DMX specification. Adapters can work well, and can offer multiple universes over 1 cable. There is an ESTA standard pinout which should offer cross compatibility, and has been designed to offer some protection from mis-plugging.

Also worth noting that often cable routing dictates splitter use long before fixture limits - i.e. doing a send and a return off a bar is more work (and points of failure) than just using 1 splitter output per bar.

32 devices per RS485 line. A proper active splitter generates a new RS485 line, so you can start counting again. So an 8 way splitter could happily feed over 200 devices.

If this is remotely recent then I’m afraid you’ve misinterpreted the advert or misremembered the rate. Our casuals are currently on Birmingham Living Wage (£10.90/hr, full BECTU terms), so above minimum wage - pay review is being voted on presently, and hopefully that rate will come up again. Our senior techs are a jump up from that (39hrs/wk annualised hours but G/O pay and other BECTU terms). Our deputies are a jump up again, and the HoDs (that’d be me for sound at Birmingham Rep) are another jump up. I wouldn’t want to quote a figure right now in public, but the Deputy HoD is certainly some distance above £11.42/hr. I’d love our salaries to be higher, but I must correct plainly wrong statements before rumours grow.

Birmingham Rep have a vacancy for a Senior Sound Technician. This role sits within a team of HoD, Deputy HoD, Senior Tech, and casual sound/video techs. Lots of produced work, some visiting work, some one-nighters, a few conferences and events. 39hrs a week annualised, salary £25,274.96 (pending annual review, so likely to go up a little), 20 days paid holiday, plus bank holidays. BECTU terms for ‘get-out’ payments, missed breaks and meal allowances. Lots of shiny toys, some less shiny toys, and a few affectionately maintained museum pieces. Closes 2nd May midday. Apply here.

Probably worth adding that I usually have a system processor betwixt desk and amps, so do my attenuation there, or at the D-A converter coming out of the processor.

I've seen trucks built in such a way that you unplug the battery from the truck and plug it into the charger - which removes any possibility of a helpful SM or stage crew type misunderstanding or forgetting the switches.

You've got everything there really. Per system 1 wireless DMX transmitter (might need to be SACN if you're doing large amounts of pixels) Per truck: 1 battery, sized to meet your needs (don't forget longer tech days, 2 show days, notes calls before shows etc.) If you can it's usually helpful to oversize the battery as it improves battery life. 1 good battery charger (get a smart charger not an old fashioned single current charger). 1 DMX receiver and dimmer/pixel controlller - these can be had as a combined unit. Power distribution and fusing - useful to add a switch to disconnect the load overnight so you don't drain your battery just running the drivers etc. Becomes more significant with pixel tape which can have a significant quiescent current. 12V batteries can provide a very very large current capable of starting fires, so an inline fuse is a sensible control measure. It can be helpful to disconnect the load during charging, but it shouldn't be essential. Be aware that voltage can rise as high as 14V during charging, so check what your devices can tolerate. However, if you've added the off switch described above, you can just flick that over. The drivers can be hired, you might struggle to hire the batteries and cabling bits as these tend to be specific to each production.

On most analogue amps the 'volume' control is a simple attenuator, not a gain control. The amp still retains its full voltage gain, it will just need a hotter input before it achieves clipping. 'Unity gain' is usually achieved by running the amp with the attenuator at full. Digital amps all vary, especially those that are specific to a manufacturer's speakers (d&b for example), and those who have speaker specific DSP models. Some Class D amps just have a passive attenuator on the front end into the amp, some use a digital 'volume control', some have very sophisticated processing available with gain limiting, voltage limiting, impedance monitoring, and lots of other fun ways to lose a day. Powered* speakers vary, the upper end models tend to have only a single line level input as you describe, but there are many models that have a mixer built in with multiple inputs some of which can be at mic level etc. I tend to run my analogue amps at full - though in one of our venues I run them attenuated for reasons of gain structure (oversized rig in a smaller venue, so with amps wide open we'd rarely exceed -30dB out on the desk). Powered speakers I usually run at whatever 0dB is. I like to get my amp/powered* speakers 'volume' controls set to something repeatable, so either on a detent or a clearly labelled position. *[unneccessary detour on powered vs active] Active speaker is an annoyingly blurry term: Some use it to mean 'uses an external crossover and multiple amp channels' - a synonym for bi-amp. Some use it to mean 'has an amplifier within the speaker cabinet' - a synonym for powered. Just to further confuse matters there are lots of powered speakers that are bi-amped. I avoid using the term 'active speaker' for all of the above reasons.

How could I forget Simon 😉

I'd talk to BECTU for full guidance, but my line would likely be that any duties that aren't part of the show call as per other performances would constitute a getout - so at the very least they'd need 1 tech to fly (and weight). (I guess the company could play a game and make the duty tech fly everything in at the end of every performance, but I can't see that lasting long) From a venue point of view, I'd also not want a visiting company operating on stage without a duty technician - and this should likely form part of your contract with visiting companies.

I've got quite close to 130dB(C) peak at the drum kit in a smallish room. UK noise law is similar, 85dB(A) LAeq over 8hrs. Two show days wipe out any gain from averaging over a shorter duration. Add in understudy rehearsals, media calls, etc. and it's clear that it is likely that few musical theatre productions are actually compliant.

There are 3 ways for a raised deck to be noisy - mostly they are all 3, but each might need a different approach to reduction. 1 - contact noise on the top surface - carpet is your best bet here, or lino etc. - or controlling what footwear your performers wear. 2 - the deck surface vibrating - a stiff deck or a damped deck is required. Good bracing in your framework, dampening the top, or a composite top. Steeldeck does well with a good stiff frame and the board fixed in multiple places. A double thickness top might also assist. Dampening could be carpet/lino on top, or something on the bottom. If you're going for composite to achieve dampening you need to ensure you don't compromise it by transmitting vibrations through the middle portion e.g. by screwing through it. 3 - the space under the deck resonating - absorptive material on the underside of the deck is a massive help with this.

Those seeking an alternative may find that Wells Fireworks can provide what they need.

There's a difference between 'running at' and peak level. Not peaking above 85dB would be likely be perceived as rather flat and lifeless for anything upbeat (and wouldn't give you much room above the average musical theatre LED lighting rig and projector setup). An LAeq of 85dB across a show with varied dynamic range is a much more reasonable target. An LAeq of 90dB allows a little more room, and for 8 shows a week the LAeq across the week usually remains within 85dB for staff (inc cast/crew etc.) As many have pointed out, acoustic ensembles can easily exceed 85dB LAeq, I've measured acoustic ensembles peaking at over 110dB(A).

What? I've read this 3 times and it's still word soup to me. Re audience vs staff - there is a note of exposure here, staff are exposed to the show 8/9/10/11/12 times a week, the audience much less often. I'm mostly on team 'why is it so loud' but equally wouldn't want every show to be limited to 85dB.

I’ve done musicals that didn’t peak beyond 90dB, and I’ve done some that hit 110dB. I’d usually advocate for keeping the LAeq below 100dB. There is a recurrent issue where SPL is equated with energy, and actually mix dynamics and tone probably contribute more to energy. However, most non-sound folk only know the words “louder” and “quieter”, so that’s all they end up asking for/shouting over the god mic…

Where I rehearse with a brass band is next door to a large chemical works that process phosphorus compounds. They have a siren that can be heard for a mile or 2 around, which is tested annually. The bandroom has a ‘red’ phone. The local canals used to catch fire as the water lapped at the edges.

DaVinci and Premiere Pro have the same. It can work well, but also can struggle - especially if the audio clocks across the multiple devices drift at all.