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90 dB + 90 dB is not 180 dB. Decibels are not on linear scale, they are on a logarithmic scale, which better approximates how humans perceive loudness. You can get around the math by adding 3 decibels for every doubling of values, so 90 dB + 90 dB = 93 dB.
For example:
The sound pressure level of one person in conversational speech is 60dB.
The maximum sound pressure level achieved in an underground railway is 100dB.
If you have two people speaking, 60dB+60dB=63dB. So the achieved SpL is 63dB. It is not 120dB, which is significantly louder than an underground railway, in fact, it is about the SpL of a rock concert.
The maximum theoretical value of sound is 194dB (which probably cant be achieved since it requires a sound-wave to oscillate into negative pressures (in Pascals))
Wiki User
∙ 11y ago
Wiki User
∙ 14y agoYes. But 45 dBm plus 50 dBm is 51.193 dBm, NOT 95 dBm. In order to explain that would take a book,
so let's leave it right there. I'm sure other contributors will jump in and add more explanation, and
may I say I'm sure that at that time it will be even more confusing.
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What is the idel op-amp CMRR?
A: Most op amp feature a 90 Db noise ratio rejection. For a 741c it varies from 70 to 90 Db ideally the bigger the number the better.
Prove dbm plus dbm equals db?
The decibel scale is a logarithmic scale where each change in three dB represents a power factor change of two. (3 dB is power times two, 6 dB is power times four, 9 dB is power times 8, etc. Similarly, -3dB is power divided by two, -6 dB is power divided by four, etc.) Zero dB is assigned some arbitrary reference power. One example is 1 mV across 600 ohms. If you double the voltage into a constant resistance, the power quadruples, so 2 mV would be +6 dB, 4 mV would be +12 dB, etc. The letter after dB is the reference power. In the case of dBm, it means that 0 dB is 1 milliwatt, so 2 milliwatt is +3 dB, etc. There are many dB scales, such as dBa, used in sound measurements. Still, fundamentally, 3 dB is a doubling of power, -3 dB is a halving of power, so, for any arbitrary scale, say dBq, then saying +6dBq is saying a power four times higher than 0 dBq. In the end, dBm plus dBm is delta dB, with no scale.
How A plus B plus C plus D plus 80 plus 90 equal to 100 what is the value of A B C and D?
If a + b + c + d + 80 + 90 = 100, then a + b + c + d = -70.
If transmitter power is increased from 200 Watts to 400 Watts how do you convert to Db form?
Decibels (db) is relative power, log base 2, times 3. Increasing power from 200 watts to 400 watts is doubling power, so the decibel change is +3 db.800 watts would be +6 db, 1600 watts would be +9 db, 100 watts would be -3 db, 50 watts would be -6 db, and so on.
How loud is 60 db?
60 dB sound pressure level is about conversational speech listened in 1 meter distance.
Which is louder 70 dB or 90 dB?
90 > 70
How many time more is the orchestra than the soloist if the orchestra has a sound intensity of 90 db and the soloist has a sound intensity of 70 db?
(90 dB - 70 dB) = 20 dB = 100 times as much sound power.(100 times 'as much' = 99 times 'more')
How loud does a sound have to be to do damage to your hearing?
90 db
What sound level damages your hearing?
90 db
What is the loudness in sones for 4000 Hz at 90 dB?
90 decibel is 32 sones.
What is 90 plus 90 plus 90 plus 90 plus 3 plus 3 plus 4 plus 5 plus 10?
385
90 plus 90 plus 90 plus 90 pus 120?
480
What is OSHA's noise limit?
Effectively, OSHA has two noise limits that apply simultaneously. First, employees may not be exposed to a full-shift (8-hour) time-weighted average noise level of 90 dB (deciBells) or more. This translates to a limit of: 90 dB averaged over an 8 hour day, or 95 dB for 4-hours as long as the rest of the day does not involve exposure to noise greater than 90 dB, or 100 dB for 2 hours, 105 dB for 1-hour, 110 dB for 30 minutes, 115 dB for 15 minutes, and no continuous noise louder than 115 dB In addition, employees who have 8-hour exposures of 85 dB or more must be placed in a Hearing Conservation Program and, in some cases must be provided with hearing protection. The table is a bit different because sounds from 80 dB and above are used in the assessment. This translates to a criterion level of: 85 dB averaged over an 8-hour day, or 90 dB for 4-hours for 4-hours as long as the rest of the day does not involve exposure to noise greater than 80 dB, or 95 dB for 2 hours, 100 dB for 1 hour, 105 dB for 30 minutes, 110 dB for 15 minutes
Is a sound that measures 100-dB ten times louder than a 10-dB?
90
How loud is 95 db?
Sounds from 90 db and up can eventually damage hearing. but 95db is equivalent to a subway train from 200 feet.
What is the answer of 90 plus 90 plus 90?
270
When the power of a system drops by 90 percent its dB value changes by?
-10
