Surround sound bodge

[benash]

First up I've never done anything with sound till now so forgive me if this is a stupid question/wrong terminology.

 

I'm doing the tech for an upcoming community show that has a bunch of sound cues I'll be running off my laptop. One of the scenes calls for some audio to be played from the back of the hall, the audio is of a bloke yelling. I'm thinking if I get one of the powered speakers that they have and set it up the back running off one of the foldback outs from the desk I should be able to turn up the foldback on the channel that the laptop's feeding and turn it down on the masters and get the sound coming from the back of the hall. Is this right? Am I missing something critical? Is there a better way?

 

The desk is a budget 32 channel thing, from Pro-tek IIRC, not sure what speakers we have. Some sort of foldback wedge I think. Tech budget is basically zero so anything I do has to be pretty basic.

 

Just to get clever, there's another sound cue (of arrows in flight) that really wants to pan from the back of the room to the front. any suggestions on how to do that?

 

Ask if you need more info, thanks for your help.

 

Ben

[Kevin Ross]

Well when I was reading your post I agreed with your first idea of using an aux send for the speaker(s) at the back of the hall. That was until you mentioned the arrows part. I would say to rotate the whole sound setup 90* so the front of the hall is the “Left” side of the PA and the rear is the “right” make sure that any music etc is panned hard left. You can then use your pan pot/have the FX panned to sweep the sound from left to right (which is now front to back).

 

 

 

Other options would be getting into tricky routing on the desk and might require additional outputs from your laptop, I have assumed that you are just using a soundcard with 2 outputs.

 

 

 

If you had more outputs to hand you could dedicate 3 channels like this

 

 

 

Channel 1 --> Music L --> PA Left

 

Channel 2 --> Music R --> PA Right

 

Channel 3 --> Rear Fill FX --> Rear Speaker

 

 

 

Normal stuff would be played through outputs 1&2 on your PC. The shouting man would just go through channel 3 and the arrows would be panned from 3 to 1&2

 

HTH

[themadhippy]

For the arrow why not just do a cross fade from aux feeding the rear speakers to the main L+R outs

[Kevin Ross]

For the arrow why not just do a cross fade from aux feeding the rear speakers to the main L+R outs

 

Unless I was using a digital desk where I could automate the sequence I would try to stay away from that as I would have to balance a rotary control and a liner control and get them in perfect sync each time over a relatively short space of time. (I’m assuming here that the aux master are not on faders, if they are then you could make this work by using the master faders as opposed to the channel controls)

 

 

 

In a ghetto/bodge situation it would work but nothing something I would ever plan to do. I still thing the best option based on only have 2 outputs would be to have the left side controlling the FOH speakers and the right controlling the rear set.

 

 

 

Unless of course stereo effects are needed at FOH then it’s a question of which is the lesser of two evils and which is the biggest pain to do

[benash]

I'll have to check the desk to find out what masters there are. The other tracks that are being played are just music ripped from CD.

[Bobbsy]

Until we know the capabilities of your desk it's hard to be specific but I agree that the arrow effect would be best handled with the pan incorporated into the recording. If you can use the idea of mono at FOH and the using the pan to control the rear speakers, this could be as easy as building a pan into the effect recording.

 

Bob

[themadhippy]

Aint none of you got a sense of adventure these days?

Another thought is to either jump the play back source or use another play back machine into another pair of channels,routed so one channel is aux only and the other channel to left and right and record the effect with the panning already done

[J Pearce]

Do the sound fx have to go through the main desk?

 

Why not cable the output of the pc to a sound rig that runs front-back not left-right? Preferably via a balancing transformer or a small sound desk.

 

Then make the voice effect panned to the L channel only of a stereo file and pre make the flying arrow as a stereo file.

 

As a warning though, amplitude panned effects tend not to work very well side on to a listener, and especially not over a wide distance. You will find that the precedence effect means that most listeners will hear it in the rear speaker then it will snap to the front speaker.

 

All that said, if it pans fast enough the illusion can work.

[benash]

Thanks for the replies folks, I think you've given me a enough to work with. J Pearce, if I had the budget would there be a better way of achieving this effect that would get over the problems you mentioned?

 

Cheers,

 

Ben

[J Pearce]

Wavefield synthesis works nicely, but as that normally requires a solid line (or surface) of speakers, its generally impractical

 

Basically the more speakers you add in the pan, the more 'snap' points you have, and the more realistic it sounds.

You can also experiment with delay panning as well as amplitude panning. (As the arrow moves decrease the delay in the front speaker whilst increasing the amplitude and increase the delay in the rear speaker whilst decreasing the amplitude.)

 

However, the ear system really isn't too good side on as it's only using one ear not two, so has little ability to 'localise' sounds.

 

It seems I have been listening in lectures <_<

[andy_s]

maybe the answer is to ask the director to get the person firing the arrow to stand on one side of the stage rather than at the back. This has the advantage of maintaining the long-respected dramatic convention of "the fourth wall", and will make your panning easier.

 

alternatively, why not try a real arrow rather than a sound effect. If it is being fired towards the stage, then the only risk of damage is to an actor, and heaven knows they are ten a penny. (unless of course a very tall member of the audience decides to stand up at the wrong moment).

[benash]

maybe the answer is to ask the director to get the person firing the arrow to stand on one side of the stage rather than at the back.

 

alternatively, why not try a real arrow rather than a sound effect. If it is being fired towards the stage, then the only risk of damage is to an actor, and heaven knows they are ten a penny. (unless of course a very tall member of the audience decides to stand up at the wrong moment).

 

The scene is a horde of Englishmen shooting arrows at a horde of Scotsmen. The blocking is such that it really needs to come from the back of the hall. I'll have a chat to the director and see what he thinks. I was actually thinking about how to get a bunch of arrows to hit the stage in a somewhat realistic manner but gave up on account that they would bounce when they hit the ground which would look a bit odd. Given that the effect will run for about a second I don't think it will kill it if it sounds like it's snapping between the back and front.

 

Edit for SPAG

[mervaka]

if you were to record the panning as bobbsy suggested, you could have a whole volley of arrows fly across people's heads, all individually panned <_<

[andy_s]

maybe the answer is to ask the director to get the person firing the arrow to stand on one side of the stage rather than at the back.

 

alternatively, why not try a real arrow rather than a sound effect. If it is being fired towards the stage, then the only risk of damage is to an actor, and heaven knows they are ten a penny. (unless of course a very tall member of the audience decides to stand up at the wrong moment).

 

The scene is a horde of Englishmen shooting arrows at a horde of Scotsmen. The blocking is such that it really needs to come from the back of the hall. I'll have a chat to the director and see what he thinks. I was actually thinking about how to get a bunch of arrows to hit the stage in a somewhat realistic manner but gave up on account that they would bounce when they hit the ground which would look a bit odd. Given that the effect will run for about a second I don't think it will kill it if it sounds like it's snapping between the back and front.

 

Edit for SPAG

 

I'm very sorry - I wasn't being entirely serious, in response to the ultra hi-tech solution proposed by another poster (even though you'd been very clear about your budget). My apologies. My real opinion is that your final sentence is absolutely on the button.

 

as a quasi borderer (on the English side of the Tweed) I like the idea of a horde of english firing arrows at a horde of scotsmen. trouble is, they tend to shoot back! and who can blame them?

 

(just for clarity, I live and work in London, but my family was until recently based in Branxton, which is the real site of the Battle of Flodden Field - not Flodden at all. and if the King of Scotland had stuck to his guns (quite literally) he probably would have won.)