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As a karaoke jockey, you are much more likely to get a two-way than a three-way. Maybe at home, you may have a three-way, but you probably have a two-way at your gigs.
I am talking, of course, about speakers. Specifically, the number of speakers per cabinet. A two-way speaker has a woofer (for the low notes) and a tweeter (for the high notes) in a single cabinet. A three-way speaker will add a midrange speaker to this. Almost all PA equipment will have a woofer and a tweeter in a single cabinet.
Active versus passive
In a previous section, I described various ways that the pieces of a karaoke system are combined. In particular, I spoke about integrating the amp into the speaker to form an active speaker, which is also known as a powered speaker. The standard speaker (with no internal amp) is referred to as a passive or unpowered speaker.
My examples in this section are largely aimed at the unpowered speakers, although most of the concepts apply whether there is an amplifier in the speaker cabinet or not.
What do you get with a bigger woofer?
The bigger the woofer, the better the bass. To give an idea how this works, let's look at a series of speakers from Phonic. These low end speakers are sold in a 10", 12", and 15" versions. You can see in the table below that the 10" speaker goes down to 65 Hz, the 12" goes down to 60 Hz, and the 15" goes down to 50 Hz.
Phonic S710 10" 65 Hz to 20 kHz $70 each
Phonic S712 12" 60 Hz to 20 hHz $100 each
Phonic S715 15" 50 Hz to 20 kHz $150 each
Unfortunately, the size of the woofer is really what dictates bass response, and ultimately, the size of the woofer drives the cost, the size, and the weight of a speaker. If you want a good thump coming out of your system, the speakers will be big, heavy, and expensive.
But my earbuds have excellent bass response, and they aren't anywhere near 15". What's up with that?
The difference has to do with the fact that bass notes just don't travel that well. If you put a tiny speaker (as in earbuds) very close to your ear, the bass will be much louder than when you pull the earbuds away from your ear. If you hold the earbuds even a few inches from your ear, the sound becomes very tinny.
Watts - peak, program, continuous, RMS
The wattage ratings on speakers are probably the most confusing and most abused spec.
The power handling spec is the number of watts that are safe for a speaker. It indicatives how much power you can pump through the speaker before you start damaging it.
Note that this is different than the wattage ratings that we put on light bulbs. If I compare a 60W bulb with a 100W bulb, I will see a change in brightness. If I replace a 60W speaker with a 600W speaker, there will not be a big increase in volume. But there will be a big difference in how loud I can turn the amp before the speakers self destruct.
Wattage for a speaker could be reported as "peak", "program", "continuous", or "RMS" wattage. How confusing. The "peak" power handling is the highest of the numbers, indicating the hypothetical level of a quick "pop" that could blow out the speaker. "Program" power is generally about half of that number, and "continuous" or "RMS" numbers are generally half of that number.
So... if you want to compare the power handling of two speakers, you need to first make sure that the numbers are expressed in the same units. I'm not sure any of the units are better than any others, so I will just say that I am going to work with "continuous power".
If there is a spec for peak power, divide by four to get RMS power.
If there is a spec for program power, divide by two to get RMS power.
If there is a spec for continuous power, then multiply it by 1. Or divide by 1. Or add zero. The RMS power handling is the same as the continuous power handling.
Sound pressure level
I said that a higher wattage rating on a speaker doesn't necessarily make the speaker louder. It's not just the watts, but also what the speaker does with them. The "SPL" (sound pressure level) is a measure of how efficiently a speaker deals with those watts. The speaker is hooked up to an amp delivering a standard amount of power. A sound level is measured at a standard distance from the speaker. The result is called the SPL.
The SPL of a speaker is measured in dB, with typical numbers in the high 90's. SPL ratings can be a bit deceptive. The range for the SPL might be only a few dB, but a difference of 3 dB represents a doubling of the amount of sound.
What the specs don't tell you
Power handling is only part of the story. Sometimes loud is all you really want. Like if you are trying to scare squirrels out of your attic. But usually, you want good and loud. Just because 100W does not damage a speaker, it doesn't mean that it sounds good. Unfortunately, there isn't a spec for how good a speaker sounds. Sorry.
I have gone through the immense trouble to compile a list of specs on a number of 12 inch speakers.
Speaker Freq. resp Power hand. SPL Wt Cost
Gemini GSM-1260 50 Hz-20 kHz 100W RMS ?? 24 lbs $70
Phonic S712 60 Hz-20 kHz 75W RMS 95 dB ?? lbs $100
Behringer 212XL 65 Hz-18 kHz 200W RMS 95 dB 24 lbs $150
Peavey PR 12 54 Hz-21 kHz 200W RMS 97 dB 33 lbs $170
Yamaha BR12 65 Hz-20 kHz 125W RMS 97 dB 35 lbs $250
JBL JRX112M 60 Hz-16 kHz 250W RMS 99 dB 43 lbs $320
What to conclude? It would seem from the specs listed that the Gemini speaker at $70 is just about the equivalent to the Yamaha at nearly four times the cost. Like I said, unfortunately, there isn't a spec for how good a speaker sounds.
As a karaoke jockey, you are much more likely to get a two-way than a three-way. Maybe at home, you may have a three-way, but you probably have a two-way at your gigs.
I am talking, of course, about speakers. Specifically, the number of speakers per cabinet. A two-way speaker has a woofer (for the low notes) and a tweeter (for the high notes) in a single cabinet. A three-way speaker will add a midrange speaker to this. Almost all PA equipment will have a woofer and a tweeter in a single cabinet.
Active versus passive
In a previous section, I described various ways that the pieces of a karaoke system are combined. In particular, I spoke about integrating the amp into the speaker to form an active speaker, which is also known as a powered speaker. The standard speaker (with no internal amp) is referred to as a passive or unpowered speaker.
My examples in this section are largely aimed at the unpowered speakers, although most of the concepts apply whether there is an amplifier in the speaker cabinet or not.
What do you get with a bigger woofer?
The bigger the woofer, the better the bass. To give an idea how this works, let's look at a series of speakers from Phonic. These low end speakers are sold in a 10", 12", and 15" versions. You can see in the table below that the 10" speaker goes down to 65 Hz, the 12" goes down to 60 Hz, and the 15" goes down to 50 Hz.
Phonic S710 10" 65 Hz to 20 kHz $70 each
Phonic S712 12" 60 Hz to 20 hHz $100 each
Phonic S715 15" 50 Hz to 20 kHz $150 each
Unfortunately, the size of the woofer is really what dictates bass response, and ultimately, the size of the woofer drives the cost, the size, and the weight of a speaker. If you want a good thump coming out of your system, the speakers will be big, heavy, and expensive.
But my earbuds have excellent bass response, and they aren't anywhere near 15". What's up with that?
The difference has to do with the fact that bass notes just don't travel that well. If you put a tiny speaker (as in earbuds) very close to your ear, the bass will be much louder than when you pull the earbuds away from your ear. If you hold the earbuds even a few inches from your ear, the sound becomes very tinny.
Watts - peak, program, continuous, RMS
The wattage ratings on speakers are probably the most confusing and most abused spec.
The power handling spec is the number of watts that are safe for a speaker. It indicatives how much power you can pump through the speaker before you start damaging it.
Note that this is different than the wattage ratings that we put on light bulbs. If I compare a 60W bulb with a 100W bulb, I will see a change in brightness. If I replace a 60W speaker with a 600W speaker, there will not be a big increase in volume. But there will be a big difference in how loud I can turn the amp before the speakers self destruct.
Wattage for a speaker could be reported as "peak", "program", "continuous", or "RMS" wattage. How confusing. The "peak" power handling is the highest of the numbers, indicating the hypothetical level of a quick "pop" that could blow out the speaker. "Program" power is generally about half of that number, and "continuous" or "RMS" numbers are generally half of that number.
So... if you want to compare the power handling of two speakers, you need to first make sure that the numbers are expressed in the same units. I'm not sure any of the units are better than any others, so I will just say that I am going to work with "continuous power".
If there is a spec for peak power, divide by four to get RMS power.
If there is a spec for program power, divide by two to get RMS power.
If there is a spec for continuous power, then multiply it by 1. Or divide by 1. Or add zero. The RMS power handling is the same as the continuous power handling.
Sound pressure level
I said that a higher wattage rating on a speaker doesn't necessarily make the speaker louder. It's not just the watts, but also what the speaker does with them. The "SPL" (sound pressure level) is a measure of how efficiently a speaker deals with those watts. The speaker is hooked up to an amp delivering a standard amount of power. A sound level is measured at a standard distance from the speaker. The result is called the SPL.
The SPL of a speaker is measured in dB, with typical numbers in the high 90's. SPL ratings can be a bit deceptive. The range for the SPL might be only a few dB, but a difference of 3 dB represents a doubling of the amount of sound.
What the specs don't tell you
Power handling is only part of the story. Sometimes loud is all you really want. Like if you are trying to scare squirrels out of your attic. But usually, you want good and loud. Just because 100W does not damage a speaker, it doesn't mean that it sounds good. Unfortunately, there isn't a spec for how good a speaker sounds. Sorry.
I have gone through the immense trouble to compile a list of specs on a number of 12 inch speakers.
Speaker Freq. resp Power hand. SPL Wt Cost
Gemini GSM-1260 50 Hz-20 kHz 100W RMS ?? 24 lbs $70
Phonic S712 60 Hz-20 kHz 75W RMS 95 dB ?? lbs $100
Behringer 212XL 65 Hz-18 kHz 200W RMS 95 dB 24 lbs $150
Peavey PR 12 54 Hz-21 kHz 200W RMS 97 dB 33 lbs $170
Yamaha BR12 65 Hz-20 kHz 125W RMS 97 dB 35 lbs $250
JBL JRX112M 60 Hz-16 kHz 250W RMS 99 dB 43 lbs $320
What to conclude? It would seem from the specs listed that the Gemini speaker at $70 is just about the equivalent to the Yamaha at nearly four times the cost. Like I said, unfortunately, there isn't a spec for how good a speaker sounds.
Copyright (c) 2010, John Seymour
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