By Ben Stowe, CTS – “Sound & Lighting Guru
“Watts” the difference between one passive or powered loudspeaker from another? As the president of NLFX Professional, I and my staff get asked this type of question all the time.
I frequently find myself addressing a wattage-based specification. I suppose it’s just one of those things that has become so widely used as a barometer for a loudspeaker, maybe DJs just don’t know what else to lead with in the conversation.
Wattage is simply a measure of electrical work, but, it isn’t very indicative of a loudspeaker’s actual performance. The number of watts doesn’t tell us a lot about how the speaker will sound, or even how loud it will get.
There are a number of characteristics you should consider when comparing loudspeakers. In no particular order they are:
- Frequency response / Crossover point
- Coverage pattern
- SPL (How loud it gets)
- Appearance / Aesthetics
Breaking It Down
Frequency Response (Illustration 1)
What sounds does the speaker make and how evenly does it make them? Think about it like a piano keyboard. You have a range of sounds from low to high frequencies. How much of the keyboard do you need that speaker to reproduce? Will it have help (e.g., a top and a subwoofer) or will it have to do it on it’s own.?
It’s essential that your speakers are up to the challenge of your gigs. Also, if you use a full range loudspeaker in conjunction with a subwoofer, they should compliment each other so that none of those “keys” are missed.
I prefer a loudspeaker with a fairly flat response, meaning it reproduces all the frequencies fairly equally.
Coverage Pattern (Illustration 2)
You need to maximize the output of your loudspeakers, and control intelligibility. Making noise simply isn’t enough. We need to make good, clear audio. Music should sound pleasing, and speech should be easy to understand.
For DJ applications typically speakers with a wider horizontal coverage and a narrower vertical coverage are ideal.
SPL (Sound Pressure Level) (Specs) – Your speakers should be able to produce adequate sound levels without distortion, and be capable of handling these levels over a long period of time while accommodating peaks in the music. Sound pressure is measured in decibels (dB).
Sensitivity (Specs) – How much power does it take to make that SPL. Think about this like “Miles per gallon.” If we can achieve the same amount of decibels with less wattage, then the lower wattage speaker is more efficient. Now we can see why wattage doesn’t rate very high on my list. In the passive speaker realm, wattage is useful for matching to an amplifier, but that’s about where it ends for me.
Appearance – This is sort of self-explanatory, right? We don’t want ugly speakers. I’m not hating on ugly speakers, there’s a special place for them… just not in my rig. Beauty is in the eye of the beholder, what is ugly is somewhat subjective, but you have to be able to get along with it. Clients want us to compliment their event, and we should appear professional. The loudspeaker’s outer coating can also be a consideration. Carpeted boxes may wear over time, or become dirty. A plastic speaker, or a speaker with a “tour” coat (like truck bed liner) is much easier to keep clean, but can scratch
Weight (Specs) – This is almost always a consideration. In the mobile world, the loudspeakers need to be moved in, fitted on stands, taken off stands, and moved out for every event. How strong you are or whether or not you use a roadie are considerations when choosing how much speaker you can easily lift. And keep in mind, the loudspeakers always seem to double in weight from the beginning of the night to the end of the night.
Price – Price is ALWAYS an object. The performance difference between a $250 loudspeaker and a $700 loudspeaker is likely very, very big. It is for you to decide what the appropriate budget is for your business. However, if you find yourself closer to the $250 mark for a loudspeaker you plan to count on weekend in and weekend out, I might urge you to reconsider.
Specs (Illustration 3)
Not All Speaker Measurements
are Created Equal
By placing boundaries (like walls in a ballroom) around a loudspeaker, we can achieve higher measured sound levels. Placing a speaker against a single boundary is called “Half-space” and increases the loudness by up to 6 dB… which is the equivalent of quadrupling the amplifier’s power (but we didn’t actually double anything).
How much it actually increases it is frequency dependent, and gets a bit murkier, but suffice to say, it’s not the same as full space (no boundaries at all). Refer back to Illustration 1 to see a comparison of full-space performance vs half-space performance from the same loudspeaker.
I prefer “Full Space” measurements because they tell me the speaker’s true performance. I can add the boundaries later if I see fit and/or it’s practical.
However, as long as the manufacturer tells me how their measurement was derived (as is in the provided illustration) some very quick, easy math tells what what I need to know and I’m a happy guy. Unfortunately, we’re largely dependent on the honesty of the manufacturer for these specs, so we have to decide for ourselves how much faith we want to put in them.
One Engineer at a large loudspeaker manufacturer lamented, “As far as I know there is no government agency that watches or regulates loudspeaker or sensitivity specs – if there was, there would be plenty of folks in jail right now. The best way for consumers to deal with this to be aware of industry standard testing methods, understand how they work, and question manufacturers that don’t list or publish their testing methods on data sheets.” Well said, anonymous geek brother!
How to Treat a Loudspeaker Purchase
I find that it makes sense to treat a loudspeaker purchase like the long term capital purchase it is. Determine how many years you intend to use it and how many shows you are likely to use it at. Then, divide the purchase cost into that number and you will have an amortized cost. You can then weigh any anticipated maintenance costs, as well as resale value at the end of that period if you replace it.
For example. If a loudspeaker is purchased for $500 and is used for 26 events a year for 5 years, the amortized cost of the loudspeaker is about $3.85 per event. If you sell the loudspeaker for $100 at the end of it’s service life (to you) that amount is now about $3.08 per event.
The “x-factor” is that a higher quality loudspeaker not only likely sounds better (and hopefully attracts more business for you) but should also have a more trouble-free service life.
It’s notable that even Ferrari dealerships have service departments, and they do so for a reason. Everything can fail, but anyone who has driven a high performance sports car can clearly appreciate the difference from the average compact car.