Loudspeakers Explained
Learn about Loudspeakers and how to configure the perfect PA system that will work for your next event. Mike will walk you through how to get the most power and all the components you may need for your set-up. Compare the benefits and learn the basic of power or passive speaker systems.
Hello, everyone. This is Mike Turner reporting from Pro Sound and Stage Lighting's show room. Today we're going to spend some time talking about PA systems in reference to loudspeakers and kind of how to figure out what kind of speaker is going to work right for your application.
As we know the active or powered loudspeaker type has been growing greatly in the last few years as technology has advanced. You can get more power out of these. You can get internal crossovers and they're a lot more controllable and a lot more user-friendly. And then we have the traditional ever so popular passive system where you require some extra components to make the speaker work. So this might be somewhat rudimentary but at the same time we want to make sure that everyone's on the same page of some of the basics of what you need to make these systems work and what kind of applications they're going to work best in.
We'll start off by explaining a couple things with an active loudspeaker system. So before I go straight into that, basically the way a speaker works, there's going to be a tweeter and then there's going to be a cone. There's going to be an internal crossover and then there's going to be some sort of a power system that's going to send the signal and power to those speaker so that they can replicate the sound. In an active loudspeaker system the amplifier is going to be built inside the speaker itself. So there's no need for external cables with respect to sending power to the speaker or anything of that nature. You simply just plug it into the wall, you send it its audio signal, and you can attenuate the volume level with the on-board controls and you're pretty much good to go. Most active loudspeakers these days have an internal crossover so it will be able to designate which frequencies go to the cone and which frequencies will go to the tweeter; which is obviously taking a lot of the technical work out of your responsibility.
And that's where the main reason people like this. Literally you take a speaker, put it on the stand, give it an audio source, plug it into a wall, and it's ready to go. You don't have to buy a fancy rack. You don't really need any extra components at all. A lot of people like these but there are some downfalls to them, again because the manufacturer sets the crossover points. You don't really have any control over that so the uber techie guy or a techie audio professional guy doesn't have the kind of control that he's probably used to and he may not like that.
There's also kind of a I guess you'd call it a misconception that powered loudspeakers have less headroom if you will. The reason being is the amplifier inside is built specifically for this particular speaker so we can kind of touch base on that a little bit but essentially what I wanted you to understand is a active loudspeaker is getting its power source from an internal amplifier built within the enclosure itself. Okay?
Now we're going to talk about a passive loudspeaker. Imagine this same thing but the amplifier is not built inside. There is no components, nothing, no tricky electrical stuff. It's literally just the tweeter in a two-way system and the horn and then you just really have an insert essentially and there's some crossover points as well. But anyway, they require an external amplifier, and I'll kind of walk you over here, something along these lines that will actually send it the power.
Now one thing I want to make sure everyone takes note of, there's a huge misconception with these knobs here. Everyone seems to think that this is a volume knob. It is not a volume knob. It is an actual level or an output knob and this can definitely be displayed by the fact that I can turn these all the way up when the amp is on and yes you will hear a volume increase but that's because I'm sending more juice to the speaker. But if I have this plugged into a mixer and I turned the main levels all the way down you will hear nothing yet these volume knobs are up all the way. So again just kind of wanted to touch base on that. A passive loudspeaker system requires an external amplifier which in return will require cables to come from the amplifier to go to the speaker.
So now that we understand the differences in the two major type of loudspeaker systems we're going to talk a little bit about applications. And again, this is up to interpretation but I'm just going to give you some rules of thumb that will kind of help you figure out what type of system will work best for you. So we'll start off with your mobile DJ. This is a customer that might be doing the gig in different types of venues each night. He has no idea where the stage is going to be before he shows up. I mean it is just completely mobile.
That sort of person would probably most benefit from a active or powered loudspeaker system; main reason being typical mobile DJ's are usually bringing in two loudspeakers and sometimes a subwoofer. The amount of gear that he has to bring in to make an active out system work is a lot less than a passive. He doesn't need a rack full of components that are going to do all the fancy work for him because it's already done inside of this. So it's typically where you're going to go with them. That doesn't mean a mobile DJ can't or won't want to use a passive system. It just requires some extra components, extra cables. It might take a little bit longer to set up. So the jist of this again to understand is that an active loudspeaker is meant to be plugged and play.
Some scenarios where a passive loudspeaker system are going to work best are generally going to be permanent installs and I'll give you some tips on that but the main reason being is because the speakers aren't being moved a lot of people like to run the cables around the parameters of the building and then they have a central station where the amplifiers are mounted, typically where everyone can see what's going on.
