Wanna know term of loudness

[surinder1508]

Hello guys Some body please tell me what is the indicative term of loudness as I'm confused in between SPL,db,RMS,Max power handling (watts)

So I can decide easily by that term given for a product that how loud it could be at most.

 

[greenhorn]

SPL is one way of measuring the loudness, as you've asked
dB is the unit in which it is measured
RMS = route mean square Power a loudspeaker can handle. If you were to drive a speaker off a constant signal ( unlike music, in which the loudness varies) this is the power it can handle
Max power handling is supposedly the maximum power a speaker can handle. This spec can be twisted a wee bit. I could say my speaker could handle 40000W for a nanosecond, and it could still be true. On the other hand, A speaker (due to the inherent nature of music) can handle more instantaneous power then its rated RMS power.

You can determine the relative loudness of a speaker by its sensitivity , which is the loudness , in dB of a speaker , at 1m away, when driven by 1W.

Loudness increases logarithmically with increase in power. a double in power = 3 db increase in dB, 10x power = 10dB increase

 

[kapvin]

SPL is one way of measuring the loudness, as you've asked
dB is the unit in which it is measured
RMS = route mean square Power a loudspeaker can handle. If you were to drive a speaker off a constant signal ( unlike music, in which the loudness varies) this is the power it can handle
Max power handling is supposedly the maximum power a speaker can handle. This spec can be twisted a wee bit. I could say my speaker could handle 40000W for a nanosecond, and it could still be true. On the other hand, A speaker (due to the inherent nature of music) can handle more instantaneous power then its rated RMS power.

You can determine the relative loudness of a speaker by its sensitivity , which is the loudness , in dB of a speaker , at 1m away, when driven by 1W.

Loudness increases logarithmically with increase in power. a double in power = 3 db increase in dB, 10x power = 10dB increase

SPL, measured in dB, is the measure of sound pressure.

Loudness, or the ears perception of volume, is measured in Phons. human perception of loudness varies with frequency and with absolute sound pressure.

for eg - 80Db= 80Phons at 1khz but 120Db=80Phons at 20hz. what it means is that an 20hz signal would need to play at 120dB sound pressure to sound equal in volume to a 1khz note playing a 80db.

If you want to know more, check this link out

Equal-loudness contour - Wikipedia, the free encyclopedia

or check the earlier work on this

FletcherMunson curves - Wikipedia, the free encyclopedia


cheers

 

[saurabhpach]

Its dB you are looking for.

An increase of 3 dB will double the "amount" of sound that comes out. i.e a 91 dB speaker will be doubly louder than a 89 dB one.

Hope it helps

 

[josedandrew]

Its dB you are looking for.

An increase of 3 dB will double the "amount" of sound that comes out. i.e a 91 dB speaker will be doubly louder than a 89 dB one.

Hope it helps

An increase in 3dB will give only a percievable increase in volume, but demands doubling of power required.
around 10 dB increase is considered as doubling of volume, which requires 10x the power
as I understands it.

 

[doors666]

actually around 6db is considered as doubling of volume as perceived by people under test.

 

[alpha1]

SPL, measured in dB, is the measure of sound pressure.

Loudness, or the ears perception of volume, is measured in Phons. human perception of loudness varies with frequency and with absolute sound pressure.

for eg - 80Db= 80Phons at 1khz but 120Db=80Phons at 20hz. what it means is that an 20hz signal would need to play at 120dB sound pressure to sound equal in volume to a 1khz note playing a 80db.

If you want to know more, check this link out

Equal-loudness contour - Wikipedia, the free encyclopedia

or check the earlier work on this

FletcherMunson curves - Wikipedia, the free encyclopedia


cheers

AGREED.

I don't get it why ppl talk about decibels, when our ears+brains are not tuned to decibels, but rather PHONS.

Its like saying a 1000W light source without specifying the frequency.
1000W at red/near infrared will be dark/black.

1000W at yellow green spectrum will be painfully bright.

 

[anm]

this is quite interesting. Given this equal loudness this, I wonder how relevant are the ruler-flat freq response graphs.
And freq response for lower freq is given for -3dB - rather it should be for +X dB for base to sound right? Or the room factor corrects some?

 

[Thad E Ginathom]

They are completely relevant, except when listening at very low volumes, when we we will notice the "lack" of high and low ends. Perhaps the "loudness" button on some non-audiophile kit should really be called a "quietness" button!

So I can decide easily by that term given for a product that how loud it could be at most.

How useful would this be? Unless you are looking for very high efficiency speakers for a very low-powered amplifier, aren't the figures just going to indicate how quickly you get ear damage?

For units of measurement to be useful at all, we have to get familiar with them. I know the difference between a 100F fever and a 103 fever; I know how a room feels at 28C or 30C, and, roughly, how outside feels at 37C as opposed to 35C. I have little idea about dBs, especially a they come in different varieties. Further confusion comes from the fact that, when we look at at our sound editor, 0Db is as loud as it gets, and we measure negative numbers down from there until we hit noise, or, in reality, long before then, the sound gets less than ambient or less than our hearing ability. When people talk about the sound produced by speakers, jet aircraft, jackhammers, whatever, they talk in positive numbers.

Experience Decibels! Try the level and dynamic-range tests on Blind Listening Tests.

I downloaded an SPL app for the phone, but, how to calibrate it? How does one calibrate the length of a piece of string when the only things you have to measure it against are other pieces of string?