Okay, here we have our B here little stage with the four mixes on it. They're all plugged in at the moment and are theoretically ready to work. The amplifiers which are in a rack That's just over here, all switched on, correctly configured. And we have actually had a sneaky little task. So we do know they all work, I am now going to test them properly, most likely going to test the PA system at the same time, I'm going to use the pink noise generator in the desk, and I'm going to send the same noise to every component. Now there's a little trick that I have learned over the years, particularly if I'm on my own and very often, monitors from front of house in small gigs is a one engineer job.

And you'll be dealing with a band who don't have a sound engineer. So you need To have as much preparation done as you can, ideally, before the band arrive, I certainly need to know that all of my PA system works correctly before the band show up. And so one of the ways in which I do this, I'll just say I use pink noise to test the audio components. But when I'm testing the wedges, what I like to do is this are just done them all up on stage, pointing towards me. So as I know, they all sound the same as each other. Because very often, you will find that wedges that look the same as each other, don't sound the same of each other.

You can't tell by looking. And now this pair these two wedges linked together. One would expect them to sound different for two reasons. Firstly, obviously there's two loudspeakers and as we know, if you have the same audio source coming from two loudspeakers, then you have certain effects that are as a result of them both working together the coupling of the low frequencies together. It also has an effect on the impedance of the amplifier and the load that the wedges present to the amplifier. Because obviously, this has got two horns and two Wolf's connected to the one amplifier instead of the one.

So, essentially, these drivers will be connected in parallel. So, we will be having the impedance if we were to connect a third wedge to the amplifier, it would be reducing the impedance considerably more possibly below that which the amplifier is comfortable operating at certainly it is relatively easy to blow monitor amplifiers up by hanging too many wedges off them generally speaking the rules There's no more than two. I am however going to try and test these individually. Now, at the moment, my little drum monitor system here my little drum fill consisting of the sub, and the wedge is here on stage left. I believe the drummer in my musical group is a singing drummer. And we will have to see whether he's left or right handed and which side he prefers the vocal microphone from before we decide where we're actually going to put his monitor mix because obviously, it makes a great deal of difference.

Things we want to avoid are having his vocal mic pointing directly at the wedge component of the drum fill in order to eliminate feedback, for example, and obviously getting it as close to him as possible. But at the moment, I'm just going to flex this one off here. Making sure I have enough cable. You have to bring it all to the downstage edge so I can listen to it. I'm going to remove the link cable from these pair of wedges here, this center and I'm going to use the cable which has actually got the amplifier on the end of it. I'm just going to switch between these two wedges, just in order to ascertain that they all sound the same.

That will give me a decent starting point. As a side while I'm here, I'm also going to component check the PA system. So we make sure that we've got both subs and highs on both sides and Pa. So that's what I'm going to do right now. Okay, I have my five wedges on stage there. They're all pointing at me.

I'm going to touch them in a moment. First thing I'm going to do, however, is test the PA system. I prefer to have a channel, there's pink noise is basically what I'm going to use to test the wedges. The this console has an internal signal generator, I can have a single touchstone, or it can have pink noise, or pink noise is so called is because it's shaped for human hearing, as opposed to white noise, which is just random, Static Energy throughout the audio bandwidth. Pink Noise is sensitized human hearing. So we're not trying to measure things that we can't actually hear.

And it's a very useful test source. So what I'm going to do is I'm going to listen to one side of the PA system at a time and then I'm going to do an A B comparison and hope that they sound at least slightly similar to each other. So this is what the stage right house left pod stack sounds like with a bit of pink noise. Right, we got an ocean Koi, you don't need to kill anybody at this stage with it. This is just a comparative test. It's not an absolute test.

So that's the other side. And now if I be between the two, you should hear that they sound approximately similar to each other. Well, they do sound approximately similar to each other, I would not expect them to sound exactly the same as each other. As this room is asymmetrical, the ceiling is lower on one side of it than it is on the other one of the big structures near the wall, there'll be more reflections. You'll never get them to sound exactly the same, but similar enough for us to know that all the necessary components are working. So I am now going to do Same thing with the wedges, I'm going to send pink noise to each single one.

And I'm going to listen to them to make sure that they all sound the same as each other. so here we can see my five mixes, as I've already pointed out, I'm just going to send some of this pink noise to mix one, just like that. Now it's really important at this stage to make sure that because we're doing a comparative test, that the levels are all the same. So I'm going to test each individual one, component by component, then I'm going to mute them. So that's mix one done. That's mix two done.

That's mix three. This is gonna be mixed for And this will be mix five. This of course, is the drums sub, and it sounds kind of like a sub to me low frequency thing rumbling a wiener. So I'm now sending to all five of these mixes the pink noise. So I'm now just going to unmute them one by one, make sure that they sound the same as each other or at least approximately similar to each other. So here I go, is 1234.

And the drums have of course. Now at the moment, I've only just tested the single wedges. So what I'm going to do is I'm going to go to the stage and I'm going to swap the cable between the two center wedges to test the other loudspeaker, just to make sure it's signed. sounds the same as his brother. So I'll just do that right now quickly. Okay, We've done one test tested four of the five wedges, we only tested one of the son to pair.

I've now swap that over for the other one in the center pair. And I'm going to do the same thing again, just listen to the four wedge monitors, make sure they sound similar to each other. And here we go, here's 1234. And they do sound approximately similar to each other. Now, you will never get a bunch of different land speakers to sound exactly the same as each other. Even if you're running them on the same amplifiers, there will be all sorts of anomalies like cable, age of drivers, all of this kind of thing.

Can I having ascertained that all the components in all the loudspeakers I'm going to be using today work properly? I'm now going to check that all the monitors are in phase with each other. You'd be surprised how regularly one confined monitors that are out of phase with each other. I've just done a European tour of some 23 or 24 shows on I would say on at least 10 of those occasions, I found one of the four or five wedges that I was using to be able to face with the others. And very often, there is no such blank license. And this beer, you cannot naturally assume it's the loud speaker.

It could be the cable, it could be the amplifier, it could be the feed from the console. There are a lot of reasons why. And again, it's something that if I have the time, I like to get the bottom to the bottom of but generally speaking a situation like this, I'm just concerned that they're all in phase with each other, and that I know they are. And the way I do this is by using the pink noise test but instead of testing the loudspeakers one at a time I test them two at a time. So I get the pairs that are next to each other Obviously, if one is out of phase with the other, then we'll get cancellation rather than doubling. And it will sound that classic out of phase sound of thin traveling with no decent extension in the base.

So this is going to be mixtures one and two, as long as Okay, maybe I could demonstrate for you the difference, okay. So, what I'm going to do is I'm going to switch mixes one and two on together. In phase none, I'm going to flip the polarity button. And the difference, I'm sincerely hoping should become very clear and apparent. So these are the two in phase with each other. That's the polarity.

That's the polarity button. It's clear as day. There's a massive difference there and it is not a good one. Right, sure I remove that phase correction from the output and I'm just going to test the rest of the wedges. I like to test them in pairs in proximity to each other, the further away to loudspeakers off from each other, the more difficult it is to ascertain what the polarity relationship is between them. Although pretty much anywhere really you can tell, providing you can hear them both in the one spot.

So here's our one and two is our two and three is a three and four. They are on quite clearly in phase with each other. There are two kinds of wedges that are commonly used in our marketplace. While I call old school wedges, which consists of a 12 or a 15 inch loudspeaker and a separate horn, usually some sort of a one and a half or two inch compression driver screwed into the end of horn throat, which is done fitted to the Battle of the wedge by some kind of adapter. Increasingly however, though, what we call dual concentric wedges are becoming more and more popular. That is to say that the tweeter element of the loudspeaker is actually mounted in the basket of the woofer itself.

So the two components have the same center concentric in fact. So, one Brian perceived the audio to be coming from one single point because it actually is rather than it not being so in a combat in a traditional woofer tweeter wedge situation, in that situation with the woofers in the tweeters. You will have a 12 or a 15 inch loudspeaker on one side of the cabinet and a horn on the other side of the cabinet is vitally important. If you Have this situation to make sure that your wedges are in pairs. There are many venues around the world, which you've got a whole bunch of monitors that all have the horn on one side, this makes life quite difficult for symmetrical employment. If you're going to give, for example, a singer, a pair of wedges that have the horns both on the same side, it's important to make sure that it's not the cabinet but the actual center of the horn that is equidistant from the singing position, because it's the high frequency energy is that which the brain uses to judge distance and direction.

In this situation, these are dual concentric arcs. So we don't have to worry about any of that. And I have now established reasonably happily, that all of these monitors sound the same. So I'm now going to put them In the most appropriate places on stage, in order to accommodate musicians that they are supposed to be assisting. And whilst on there, I'm going to be making a few other adjustments to what goes on on stage thinking about ways of economizing in terms of space and maximizing the efficiency of the loudspeakers by getting them in the right place as well as getting the right audio output coming out of them. So that's my next task is to start actually making the stage show ready.