Speaker Frequency?


Unregistered guest
How can you tell if a speaker has better frequencies? for example, my speaker says

30-22,000 and some say 45Hz~20KHz, why does mine have the extra 3 zeros? Thanks!

Bronze Member
Username: Usa2k4

Post Number: 62
Registered: Dec-04
22,000Hz = 22KHz just like 1,000 grams= 1Kg. :-)

When comparing speakers' frequency responses, you must also be sure they're rated with the same tolerance. The wider the frequency response, the better and the tighter the tolerance, the better. For ex, a speaker with the frequency response of 40-20,000Hz +/-3dB is better than the one with 40-20,000Hz +/-6dB, the one with 30-20,000Hz +/-3dB is better than the one with 50-17,000Hz +/-3dB response. However, specs on the papers only tell you a part of the story. You must also listen to them to determine which one sounds best for you..

Silver Member
Username: Frank_abela

Berkshire UK

Post Number: 308
Registered: Sep-04
newbie indeed :-)

1khz = 1000hz. The k is shorthand for kilo (or thousand). So your speakers could be quoted as 30-22khz.

That said, when you look at numbers like that, the manufacturer is only giving you an indication of the speaker, and the straight frequency quote is not really that useful. As a speaker goes down to its lowest frequency - or up to its highest frequency - it usually tails off its volume. What's often quoted is the point where it is -3db in volume (about half). So if a speaker gives you 87db of noise at midrange (say 2khz), then the -3db point would be when it goes down to 84db. But there are some manufacturers who will quote a -6db point instead (4 times quieter than at the midrange point). The -3db point is generally accepted as the more relevant.

Another interesting number you'll see quoted is the impedance. Average impedance is usually about 8 ohms. However, many speakers are now being quoted at 4 ohms. Half the resistance means your amplifier has to work twice as hard since it has to drive twice the current for the same signal.

Finally, sensitivity. The average sensitivity speaker is 87/db/w/m. If you sat 1 metre away from the speaker, and fed it a 1 watt signal at 1khz, you would hear 87db of noise. If you have a more sensitive speaker than the same signal would generate more noise, and conversely a less sensitive speaker would generate less noise. Once caveat with sensitivity is that sensitivity depends on impedance. So a 87db/w/m speaker which is 4 ohms impedance is actually not average, it's lower than average since you're having to work hard to generate the sound. Manufacturers sometimes quote their speakers on the 4 ohm rating simply to boost their sensitivity values. You often see 90db speakers rated at 4 ohms. Well, these should be considered as the same as 87db speakers with an 8 ohm rating so they're average sensitivity.

Sorry to confuse...!

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