P.A - How to use

From The Star And Shadow Cinema Wiki

OK. The pa is alright.

Here are a set of instructions. I just wrote them so that I could give them to people who had never used any of this equipment before, so apologies if you know this stuff already!

THE EQUIPMENT It consists of:

• 2 big grey cabinets (mids and tops - only the tops work)
• 2 big red bass bins (which work great and make the pa sound half ok).
• an old mixing desk which is slightly confusing
• an amp and compressor in a little brown box on wheels (the compressor is currently unplugged, and we tend to leave it that way).
• a small 2 channel DJ mixer for attaching decks and cd players to.
• 1 working monitor speaker, which is connected with a jack cable, and is powered from the amp i think.
• Loads of mic stands
• Some mics
• not enough cables - but a bunch ofjack-jack (for guitars, keyboards etc) and some jack-xlr (a crappy way of connecting a mic to a mixing desk), and perhaps 1 or 2 xlr-xlr cables - the important ones that connect mics to the desk and speakers to the amp and which for some reason people always walk off with.XLR cables have metal ends with three little pins or 3 little holes.
• AD.I box (which you connect a guitar to and then connect the di box to the desk with an xlr cable - it reduces noise and distortion - see a proper sound engineer about this one).

THE MIXING DESK The mixing desk has 16 input channels (for musical instruments, mics, decks etc.), and 2 main sets of outputs (to go to the 'amp then speakers' and to go to monitor speakers on the stage or to a recording device (like a mini disc player if you want to record the gig).

You turn it on at the back of the desk on the right - a little silver switch. MAKE SURE VOLUMES ARE TURNED DOWN WHEN YOU DO THIS - ON THE AMP TOO!

All the inputs are 'mono' - i.e use one input channel only. If you want to put a stereo input into the desk, it should use 2 input channels (cos with stereo, certain sounds are assigned to left speaker, certain to the right speaker, so you have the left hand sounds coming in to one input, and the right hand sounds coming into the second input - e.g decks, or a dvd player)

Each input channel of the 16 can have Either 'line in' (jack) or 'mic in' (xlr). Microphones use xlr, as do DI boxes. Guitars, most keyboards, the outputs from dj mixers/ cd players/ record players/ dvd players/ mp3 players would all be connected through teh 'line in' or 'jack connector. If you have 'phono' connections on the end of your device (e.g your ipod has a little headphones connector into the ipod aka 'minijack' that turns into a red and white 'phono' connection at the end, they need to be converted to jack connectors (the fatter one which you would see on a guitar cable that fit into a 'line in' input on the mixing desk) - there are some of these phono-jack adapters in the desk already, or in the little shelving system in the projection booth.

On each input channel control column on the front of the desk, there is a little orange button at the top - if it is pressed in, it means it is the 'line in' that is connected (aka jack or guitar lead). If it is pressed out, it is the 'mic in' that is connected (xlr). Beneath that orange button is a switch which can boost the signal from the instrument. So if the mic attached is very quiet, even with the volume turned right up on the fader, you can turn the switch up a notch and it will significantly boost the volume.

The main things to use on the input channel control columns are the volumn fader and the 'eq' knobs (hi, hi-med, lo-med, lo) - these are useful to hide or reveal frequencies which make the sound better or worse. If it sounds very 'tinny', and not bassy enough, then you turn down the high knob and the lo and lo-med up. With a bit of playing around it is amazing what a difference you can make.

On the right hand side of the mixing desk, you have the master volume - which is stereo - a fader to turn up the left speaker, and a fader to turn up the right one.

On the back of the desk, you have 'master outputs' on the left hand side underneath 'input channel 1'. This is a stereo output that should go to the amp in the brown box. The main master volume faders on the front right of thedesk control the sound going out of those cables into the amp. So effectively you already have 2 ways of controlling the On the right hand side, near input 16, you have a pair of outputs you can use for the monitor speakers or a recording device.

THE AMP The amp has an on switch at the front, and two volume controls - left speaker and right speaker. These should be turned to 0 when you are turning the amp on or off.

At the back of the amp, there is space for a set of stereo inputs (left and right), and speaker outputs (left and right). So your input is coming from the desk, via jack-xlr cables, into the amplifier, to be amplified and then sent out of the amp to the speakers with xlr-xlr cables.

The left input is on the left hand side of the back of the amp, and the right input is on the right hand side of the amp, which feels kind of funny. You can either input using jack or xlr, but currently, there are yellow cables that connect to the amp using xlr connections. (and connect to the mixing desk's master output using jack connections).

The amp is fairly straightforward then. You just need to connect the desk to the amp and the speakers to the amp, and then turn the volume up.

THE SPEAKERS We tend to connect the speakers in the following way: a long xlr-xlr cable goes from the amp to each grey speaker cabinet. A short xlr-xlr cable connects the grey speaker cabinets to the red bass bins. Hey presto, you have a warm-ish sound. This isnt a healthy set up for the speakers - really the signal from the amp is meant to be assigned, so the bass frequencies go to the bass bins and the mid and high frequencies go to the grey cabniets, but to do that we need a crossover, and we would also want to seriously fix up the speakers in the gry cabinets, 50% of which are not working.

SETTING UP A BAND/DJ/MP3 PLAYER FOR BAR MUSIC Hopefully most bands will bring their own guitar amps, and you dont need to mic drums up in our small bar area. So it is only really setting up microphones. You just need to get a mic stand and mic out of the store/ heating plant room behind the bar, and connect it to the desk with a nice long xlr-xlr cable. Make sure you have assigned the correct input channel to mic (using the orange button) and you have a decent signal from the mic (using the switch under the orange button). Then fade up the input volume control, fade up the master volume controls, and make sure the volumes on the amp are both turned up (to around 12 0'clock). If it doesnt work, check that all your connections are correct, using the list above (i.e mic-mixing desk-amp-speakers). If it still doesnt work, try using a different mic or a different xlr cable - sometimes they break.

If you are setting up a dj, make sure the record decks or cd players are connected to the dj mixer (there are some switches on the back of the dj mixer which decide whether the 'line-in' or 'phono' (record player) is being controlled by the volume and therefore coming out of the speakers. Many people have fretted over why their music is not coming out of the dj mixer - it is nearly always to do with the switches on the back underneath the red and white phono jack inputs. NB 'phono' written on the input on the dj mixer relates to 'record player'. a phono cable (aka RCA connector) is what you connect a record player or cd or mp3 plyar to the mixer WITH! confusing eh!

Then make sure your dj mixer is connected with a stereo phono-phono cable (left and right cables, aka red and white phono, aka RCA, blah blah blah) to input channels on the big mixing desk (remember you need to use 2 channels because the inputs on the big mixer are mono, and you have a stereo source - the dj mixer, and also remember that you need to have two little phono-jack adapters to convert the phono cable so you can physically attach it to the mixing desk).

Make sure the orange buttons on the mixing desk are pushed IN so they are assigned to 'line in' rather than 'mic in'. Turn up the voume and play with the eq's til you get a nice sound.

If you are JUST PUTTING IN AN MP£ PLAYER for some nice music before a film - well what a nightmare eh! You need to connect your mp3 player with a mini-jack to stereo phono (the little headphones style connector to red and white RCA connectors), and then attach the phono-jack adapters onto the ends and then into 2 mono input channels and follow the same steps as above.

If there are problems, call Christo - my number is up on the board in the office.