Require heavy bass

[TheProff]

Hi everyone,

 

I am putting together the sound (and lighting) design for an amateur production of The Barnbow Canaries, which of course includes the munitions factory blowing up. I have access to an old Behringer sound desk, so I can achieve 3 or 4 separate outputs to different amps. For the explosion I am planning to use all amps and speakers, but the Director has challenged me to produce enough bass that the audience feel it.

 

Normally I would set up a test with the kit I have, but as mentioned in recent posts I have just had an op to repair a leg injury, which means that I have my leg in a full length splint which is staying on right up to the show at the end of May. So instead I am seeing if I can draw on your experience.

 

I can see that hiring an actual sub woofer is an option, and one of my amps has a sub woofer output. The stage resident speakers are small and at high level, but I also have a couple of decent sized PA speakers, approx. 400mm wide by 700mm high by 350 deep, with bass speakers almost the width of the case. I'm sorry, I can't easily get to them to get the model numbers - I really should put together a list of what I've got!

 

I know that, in basic terms, the bigger the actual speaker, the better bass it can give. From what I have described, do you think that I will get enough of a bass effect out of the PA speakers? As usual minimising the budget is key, as I will need to hire other items for the lighting such as a set of blinders!

[GR1]

No one can definitively answer this without more information although my instincts say use sub woofers [ note the plural]. If you can't get access to the speakers take photos so we can advise.

[J Pearce]

I doubt you'll get much that is 'feel-able' in a large room from anything less than a 15" driver (excepting some of the more specialist sub designs).

 

I'd look at borrowing/hiring/buying a cheap active sub. You can get something that will do rumbles and bangs for under £200, it won't be the best musical sub ever made, but it will do unsubtle generic bass which is probably all you need. Does anyone in your company know a DJ or band who could loan you a sub?

[Jivemaster]

Feelable bass for an audience of 50+ will take a lot of power and big drivers.

 

Spend some time making up the sound effect and see how much you can elongate it with multiple bangs and some reverb and maybe slow it down, Maybe even layer bits together with sfx for rubble, building collapse etc.

[csg]

we did exactly this for a 1800 capacity room as part of the 100th armistice anniversary last november. a single twin 18" sub in a central position, hidden under a stage deck supporting a machine gun, fed from a amplifier capable of delivering 3000W into the load impedance succeeded in making a lot of people jump with surprise.

 

I would strongly recommend a single sub unless you can engineer a coherent array , left / right subs will produce a lot of interference which will produce hot and cold spots as the energy from one sub adds or cancels the engird from the other. One source will give much more even coverage.

 

If you are struggling for power, corner loading will add a boundary that will give you significant gain, often at the expense of sound quality, but with VLF sound effects this may work to your advantage.

 

 

So, yes, you will need a real sub and a matching amplifier - conversely often smaller spaces are harder when it comes to very low frequency sound effects, long wavelengths like larger spaces.

[bigclive]

Any chance you could use a stage maroon in a bomb tank? (It feels so awkward saying bomb these days!)

 

A maroon will produce a huge explosion and that can then be extended with a bit of speaker noise.

[timsabre]

I do enjoy a good maroon, but it is a very short sharp bang, it sounds nothing like what people recognise as "an explosion".

 

Also it's so loud you lose the attention of the audience for a while as they try to resuscitate the person next to them.

[Jivemaster]

An explosion really is a very loud very short sound (150+dB for 2 -5 milliseconds typically), because this is un-achievable in film/tv the public is now accustomed to a much longer sound at a much lower level say 100dB for 2 seconds.

 

You could replicate the effect of an explosion with a maroon down the usual pyro route with all the usual caveats, you could replicate the public perception of the sound with a LARGE and well powered sub woofer as part of a very loud sfx cue.

 

That cue could well be created and slowed, but beware of creation methods that lose bass, allow a lot of electrical power for the cue. A bass speaker gets some enhancement from a close surface (-the floor!) and more enhancement from a second close surface such as the back wall.

 

Remember that they were called canaries because the explosive was also a dramatic yellow stain which stained everything- skin, clothes everything, with the permanence of smoker's fingers yellow.

 

The sfx could well be a bang or two or three really close together then some machinery/brickwork falling/creaking then some simple quietness to contrast the noise.

[ninjadingle]

I also would suggest going down the pyro route if competent (backed up with suitable after effects SFX), not only will you get the shock and awe but also the smell. Hell, if it's a munitions factory blowing up then it's the one time using pyro makes perfect sense!

[kerry davies]

I knew nothing about the play and little about the tragedy but seeing as it is written by Alice Nutter,

, big maroons would be 100% in context.

[pscandrett]

I also would suggest going down the pyro route if competent (backed up with suitable after effects SFX), not only will you get the shock and awe but also the smell. Hell, if it's a munitions factory blowing up then it's the one time using pyro makes perfect sense!

If it's a smallish space then perhaps a smaller pyro might be better (backed up with SFX). Even in a bomb tank, some of the stage flash type effects would let off a good old thunk which isn't necessarily as loud as a maroon - but still gives the 'explosive' noise along with the pyro smell...

[cedd]

Personal (and sometimes controversial) opinion here - anything that makes the audience jump is not the right tool for the job. I fully appreciate that a real explosion is unexpected, shocking and makes you jump. If you're wanting it to be 100% realistic then that's what you need. This is the theatre though. Anything that makes an audience jump, reach to cover their ears or generally do anything out of shock and you're going to ruin any sense of tension or emotion that's in the room. No matter what the scene, a jumping audience are going to acknowledge that with some sort of reaction. It might be a chuckle to their friend, it might be a gasp, it might even be an out loud scream or yelp. All of the above though are instantly going to draw the audience out of the moment and back in to the real world.

 

Example; I've done West Side Story several times now. Many have used stage firearms for the final scene. Some firing blanks and only a couple with sound effects. The effect of the two methods on the audience was chalk and cheese though. The sound effect, properly edited and designed, always left the theatre in utter silence. Didn't need to be loud, just needed to be subtle with a big reverb on it. Nobody jumped, nobody giggled, several people cried.

 

I could almost imagine doing a "reverse explosion" at this point in the show - at risk of quoting the Hitchikers Guide To The Galaxy, a "wop" sound and a snap blackout, followed by lights up to reveal the aftermath and a soundscape of alarms, crying, flames. wind etc. No need for a bang at all. Sorry, it's difficult to describe on a page what I'm seeing in my head. I'm pretty sure the effect has come to me from something I've seen in film though.

 

If you decide to go with your "feel the bass" effect though then fair enough. Remember that you don't need to find one sound effect that does what you need, you can piece several together. Have a search around for some LFE Sweeteners. They're often used in cinema and are just the tool for the job. I've got a library of them that I have used countless times. Do your final editing in the space, on the actual PA that'll be doing the job. Headphones won't give you any real idea of how it'll sound in the space. If you can (depends how you're playing effects back), keep the LFE channel as a separate output from your playback machine. This means you can employ separate routing and EQ to it.

 

 

 

[timsabre]

Completely agree. This is one of those common theatre situations where you just need to suggest an explosion rather than trying to make it "real".

[bigclive]

Personal (and sometimes controversial) opinion here - anything that makes the audience jump is not the right tool for the job. I fully appreciate that a real explosion is unexpected, shocking and makes you jump. If you're wanting it to be 100% realistic then that's what you need. This is the theatre though. Anything that makes an audience jump, reach to cover their ears or generally do anything out of shock and you're going to ruin any sense of tension or emotion that's in the room. No matter what the scene, a jumping audience are going to acknowledge that with some sort of reaction. It might be a chuckle to their friend, it might be a gasp, it might even be an out loud scream or yelp. All of the above though are instantly going to draw the audience out of the moment and back in to the real world.

 

The whole point of theatre is to deliver sensory stimulation above and beyond normal life. On a certain job I work on,if the pyro doesn't make the audience scream then it means we need more boom.

[themadhippy]

anything that makes the audience jump is not the right tool for the job.

realy? even on stuff like woman in black?