Chapter 12
In This Chapter
Choosing the right amplification for your wallet and environment
Getting to grips with connecting it all up
Keeping the sound down to save your hearing and your neighbours’ sanity
Each stage of the DJ equipment chain is vital. Without the amplifier and speakers, you’ll be the only person to hear how good a DJ you are. In this chapter, I cover the various methods of amplification, the best way to connect and place your speakers, and how to play at a volume that won’t get you ejected from the neighbourhood.
You need to choose a method of amplification that’s suitable for the size of room you’re playing in, and also for the size of your wallet – which are both important factors. The key word here is suitable. If you’re just in your bedroom practising at a moderate volume, you don’t have much need for a £3,000 1,000-watt amplifier and set of speakers, so save your money!
The different ways you can amplify the signal from the mixer so you can hear it through speakers are via:
Your home stereo (or hi-fi) is probably the easiest and cheapest route to go down when you’re just playing in the bedroom for practice, because you probably already own one. As long as you have a spare input channel on your hi-fi, and you can position the speakers close enough to your DJ setup so that you can get a good sound from them, your home stereo is a very good option. Although a hi-fi may not be as loud as a separate amplifier, if you’re playing in a modest-sized bedroom, it should be more than loud enough.
If you get the chance to buy a new hi-fi on which to practise, search for one that has a manual graphic equaliser on it rather than relying on some nonsense settings for ‘hall’, ‘big hall’, ‘stadium’ and ‘bread bin’ to approximate the different sounds the music would make in those areas. A manual EQ (equaliser) lets you adjust the sound to your taste by controlling a range of different sound frequencies individually. If you plan to use the hi-fi to record your mix, full control of the sound is especially important. (See Chapter 19 for guidance on recording great sounding mixes.) Even if it means another £20, you won’t regret your choice. Hi-fis with pre-set EQs are great for domestic easy listening at home; but you’re a DJ – you’re far from domesticated.
The hi-fi also needs a spare input on the back in which to plug in your mixer. If you only have CD and phono inputs on the back, you have to use the CD input. (Phono inputs are only for direct connection of a turntable.) If you already have a CD player plugged into the hi-fi, you’ll need to unplug the CD player and plug in your mixer each time you want to use do some DJing, which can get tiresome. Instead, if buying a new hi-fi, try to pick one with a separate AUX (auxiliary) input to plug your mixer into.
If you don’t have an amplifier or don’t want to tie up an input on your hi-fi with your mixer, powered speakers (also knows as active monitors) are a good alternative. Powered speakers are the same as normal speakers, except they don’t use a separate amplifier; the speakers have a built-in amplifier so you can connect the output of the mixer directly to them.
Powered speakers are very popular in the DJ booth as booth monitors. The volume control for this monitor is usually situated somewhere accessible on the side or back of the cabinet, which is perfect because you can turn it up or down whenever needed (especially if the mixer doesn’t have a separate booth-level control on it). Powered monitors in the DJ booth also don’t tie up an entire amplifier for the sake of one speaker, making good financial sense. See ‘Working with Monitors’, later in this chapter, for more about booth monitors.
For bedroom use, powered speakers can range in quality (and price) from basic computer monitors (often not the best sounding) to budget monitors such as those by M-Audio and Numark, which cost around £90 a pair and have an acceptable sound, to great-sounding powered speakers such as those made by KRK, Genelec, JBL and RCF, which can cost anywhere between £300 and £5,000 for a pair.
A powerful amplifier with huge separate speakers can be overkill in the bedroom. Five hundred watts of music can sometimes be more than you need even in a large hall, so if you buy a high-rated amplifier and speakers and turn up the volume to full, don’t be surprised if your neighbours come knocking on the door!
In non-techy talk, think about a trampoline. How low the membrane on a trampoline is to the ground when you’re standing still on it would be the average rating: it’s happy at this level, and nothing’s really going to go wrong with it. When you start jumping on the trampoline, as you land the membrane gets a lot closer to the ground momentarily. How close the membrane can get to the ground before suffering damage is the peak rating of your trampoline.
The peak value is always higher than the average value, and is why manufacturers like to print the peak in their documentation – it makes the speaker look more powerful.
Choosing the power rating of the amps and speakers, especially when considering a lot of power for a hall or club setup, takes a little forethought and needs a margin for error.
If you’re looking to buy a setup that will give you 200 watts of power, the best option isn’t buying a 200-watt amplifier and speakers with an average rating of 200 watts, nor is it buying two 100-watt amplifiers to make up a total of 200 watts of sound.
The preferred way to set up this amount of power is to buy three amplifiers and three sets of speakers, and run them all at two-thirds of their output level. Running two amplifiers at full volume for too long is running the risk of one, or both, breaking down – but three amps at two-thirds of their power will run happily for a long time. And even if one of them does blow, you’ll still only lose one-third of the power instead of all or half of the power in the other two examples.
Table 12-1 is a general guide to the room size, occupancy and power rating you may need for different situations. This guide isn’t a set-in-stone rule, and you may want more than suggested to give you a little ‘headroom’ of power, in case you want to go louder.
Table 12-1 Amplifier Power Needed for Different Room Sizes
Room and Occupancy (allows for 5–10 watts per person) |
Power Needed |
Empty(ish) bedroom (you, your bed, your decks and the cat) |
20–40 watts |
Full(ish) bedroom (a few friends are visiting) |
40–60 watts |
Big room or small half-full hall (back room in a pub) |
80–150 watts |
Large hall, half full (local Scout hall, and so on) |
150–300 watts |
Large hall, lots of people (phew, they came!) |
500–800 watts |
You may have noticed that the number of people in the room affects the amount of power you need. People are very greedy. Not only do they raid your fridge for beer and food, but their bodies also absorb sound waves, robbing some of the volume from the room. The more people that turn up, the louder you have to play the music to be heard at the same volume! The good thing is that even though you have to turn up the sound a bit, as the stray sound waves are soaked up by the crowd this can improve the sound on the dance floor.
On top of all the power mentioned above, add in a sub-woofer. You can’t get a good sound on the floor without one. Most of the frequencies lost to the furniture or flesh in the room are the bass frequencies; keep it healthy with a low frequency sub-woofer.
If you want to know how to connect multiple sets of speakers into your amplifiers (which is essential knowledge for club systems and some mobile DJs), check out the DJing page on the For Dummies website.
Your booth monitor is your link to what’s really happening on the dance floor, and can make the difference to your night going well or going to you know where. Without hearing the exact audio that’s coming from the mixer at the exact moment it comes from the mixer, you’ll have a really hard time beatmatching. In the bedroom, the ‘dance floor’ sound and the music you hear in the ‘monitor’ are the same thing (usually because they are the same thing), but in a club, the two sounds are a bit different.
The speakers on the dance floor are probably only 10 to 20 metres away from the DJ booth, and they’re sure to be loud enough for you to hear them. But volume doesn’t have much to do with how long the sound takes to get from the mixer to the speakers and then to your ears. The speed of sound is 330 metres per second. If the speakers are 20 metres away, the sound takes around 1/16th of a second to get to you. In music, this fraction of a second is an extraordinarily long time, and although it seems like a tiny delay, the delay is enough to throw your beatmatching out of time and make you sound like a complete amateur.
This is where the DJ booth monitor comes in. The monitor is often a pair of speakers either side of the DJ, but in some cases is just a single speaker positioned to the left or right of the DJ. A monitor right next to your ears cuts the audio delay from 1/16th of a second to 1/256th of a second (if it’s a metre away), which is more than acceptable.
Unless you live in a mansion, you’re unlikely to have to deal with any delay in the bedroom from your speakers to where you have your decks set up. If you do practise in an oversized room that’s causing a delay similar to working in a club, ask your butler to bring one of the speakers closer to you. Sarcasm aside, if bringing a speaker closer to you isn’t an option, then you can hook up a separate booth monitor (maybe a powered speaker) to play right next to your DJ setup, or you can add another pair of speakers to your existing setup and place them next to your homemade DJ booth.
The monitor needs to be close enough to counteract any delay from the dance floor but also overpower any music from the dance floor that you may still hear in the DJ booth. Keeping the speaker close and facing you gives you the best clarity. Too far away and you may find it harder to pick out a solid bass thump or the crisp hi-hats and snare drum that you use as reference when beatmatching (see Chapter 14).
If the monitor is too high, the bass driver dominates the tweeter, drowning out a lot of the high frequencies from the music. If the monitor is too low, aimed at your waist, the bass is lost, leaving a shrill, unclear sound dominated by the high-frequency tweeter that’s at head height. Turning the monitor on its side so both the tweeter and bass driver are at the same height helps to prevent either eventuality.
Digital DJs using controllers with computer software should be a little better off than the vinyl or CD DJ when it comes to speaker vibration. But you don’t want vibrations to cause problems with reading the hard drive.
Many reasons come to mind as to why you shouldn’t play your music loud all the time, but hearing damage (which I cover in Chapter 11), neighbour relations and the quality of your mixes are paramount.
Keeping the volume of your monitor at the lowest functional level protects your ears and reduces any risk of distortion from the headphones or the monitor.
To help with the accuracy of your beatmatching when single-ear monitoring, you only have to play the monitor loud enough to drown out the music from the dance floor. The trick is to match the volume playing in your headphone ear to the volume from the monitor in the DJ booth. Due to the proximity of the headphone on your ear, this is about perceived volume rather than trying to match the actual decibel level coming from the monitor in the DJ booth, because to do so would make you go deaf.
Keeping everything at as sensible a level as possible not only helps to delay hearing loss, but also prevents your ears from getting fatigued through the night as they’re blasted by sound. The louder the music, the quicker your brain will start to tire, and you’ll start to lose the subtleties in the music that help you in the mix – like hearing the beats go out of time before anyone else does!
Keeping the music at a sensible level to aid your mixing and protect your hearing are both important, but you also have your sense of social responsibility to think of. Not only may the rest of the people in your flat, house or building start to get a little irked when you play pounding bass beats at full volume for hours at a time, but the people in surrounding buildings may soon get fed up with the dull thudding noise coming from your house.
When you’re DJing at home, you really only need the one speaker, and that’s the one you use for the ‘live ear’ when using single-ear monitoring to beatmatch (your equivalent of a DJ booth monitor).
When a neighbour pointed out how annoying the bass of my sub-woofer was, I put switches on all of my speakers so I was able to leave only the monitor speaker running. This meant that I could play the music just as loud as before; because only one speaker was playing, the volume that other people could hear was a lot lower, yet the volume that I perceived from the monitor stayed the same. Turning off the unnecessary sub-woofer helped a lot, too!
If you’re thinking of adding switches to isolate your speakers, do some research into the best switch to use. I must admit I used light switches at first, but they’re not designed for audio signals and can add too much resistance to the signal from the amplifier to the speaker, even when the signal is just passing through the circuit. This resistance may only cause a drop in sound quality or volume, but in the worst case it may break your amplifier. Something as simple as the Hama LSP-204 (shown in Figure 12-1) can do the job a lot better for up to 100 watts of sound.
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