Quiz Time! - NO CHEATING
10-14-2004, 12:08 AM
#1
500 Watt CAFz'r
Thread Starter
Join Date: May 2004
Posts: 718
all right class, close your books and take out a pencil and eraser. it's time for a pop quiz!!!
well, actually, i was just surfing the web and found out some intesting stuff about SPL levels...
you could probably find the answers from a quick search on the net, but that would be cheating!
Q1. At how many dB's does the human ear begin to experience pain?
Q2. How many dB's is a jet engine from 100 feet away
Q3. How many hours a day is it safe to listen to sounds of 90 dB's? 115 dB's?
Q4. For a sound to be percieved as twice as loud as the original, how much of a dB increase would you need?
Q5. What is the average dB of a walkman (half of max volume) when earphones are used?
Q6. How much of the total power from a 75 instrument orchestra come from the bass drum?
Q7. True or False: Hypertension and psychological difficulties canresult from excessive noise exposure.
Q8. True or False: dB, or Decibel, comes from the German scientist Hanz Bel.
Q9. For the average car stereo, if using 1000 watts of power, what is the recommended amount of capacitance (in farads) to achieve an undistorted power signal?
Q10. What is the loudest possible sound (in dB)?
***** QUIZ OVER *****
(please go down to see answers)
^
^
^
^
^
^
^
^
^
^
^ KEEP ON GOING
^
^
^
^
^
^
^
^
^
^A LITTLE FURTHER
^
^
^
^
^
^
^
^
^
^
^HOW BAD DO YOU WANT THESE ANSWERS
^
^
^
^
^
^
^
^
^
^
^AND HERE THEY ARE....
^
^
ANSWERS:
Q1: 125 dB and your ears will start to get soar.
Q2: approx. 130 - 140 dB's at 100''/35m
Q3: 90 dB's = 8 hours , 115 dB' = 15 mins (or less)
Q4: 10 dB's to the human ear to double SPL, in actual principle, a 6 dB gain would occur if you doubled the amplitude (power) of the output signal.
Q5: 94 dB, when the earphones are placed near to the ear the intensity is much greater on the ear drum.
Q6: about one third (1/3) of the total sound power of a 75 instrument comes from the bass drum.
Q7: TRUE, loud noises cause anziety and stress on the body causing the blood pressure to rise and brain to take abnormal activity (that explains a lot!)
Q8: FALSE, the decibel comes from "deci" = ten and "bel" = difference between two intensities.
Q9: most average systems can suffice with 1 F of capacitance for every 1000 W of power, however, for some higher drain systems 2 F is needed for uninterrupted power.
Q10: YES, there is a loudest sound possible, on the decibel scale, a sound could not get any louder (to the humen ear or any measurable device) after reaching....194 dB! which means that dB drag racing could become obsolete if we can somehow manage to squeeze ~20 dB's out of the loudest SPL vehicles! (don't worry, won't be for a long time).
SCORE YOURSELF OUT OF TEN AND GIVE YOURSELF A PAT ON THE BACK!!!
well, actually, i was just surfing the web and found out some intesting stuff about SPL levels...
you could probably find the answers from a quick search on the net, but that would be cheating!
Q1. At how many dB's does the human ear begin to experience pain?
Q2. How many dB's is a jet engine from 100 feet away
Q3. How many hours a day is it safe to listen to sounds of 90 dB's? 115 dB's?
Q4. For a sound to be percieved as twice as loud as the original, how much of a dB increase would you need?
Q5. What is the average dB of a walkman (half of max volume) when earphones are used?
Q6. How much of the total power from a 75 instrument orchestra come from the bass drum?
Q7. True or False: Hypertension and psychological difficulties canresult from excessive noise exposure.
Q8. True or False: dB, or Decibel, comes from the German scientist Hanz Bel.
Q9. For the average car stereo, if using 1000 watts of power, what is the recommended amount of capacitance (in farads) to achieve an undistorted power signal?
Q10. What is the loudest possible sound (in dB)?
***** QUIZ OVER *****
(please go down to see answers)
^
^
^
^
^
^
^
^
^
^
^ KEEP ON GOING
^
^
^
^
^
^
^
^
^
^A LITTLE FURTHER
^
^
^
^
^
^
^
^
^
^
^HOW BAD DO YOU WANT THESE ANSWERS
^
^
^
^
^
^
^
^
^
^
^AND HERE THEY ARE....
^
^
ANSWERS:
Q1: 125 dB and your ears will start to get soar.
Q2: approx. 130 - 140 dB's at 100''/35m
Q3: 90 dB's = 8 hours , 115 dB' = 15 mins (or less)
Q4: 10 dB's to the human ear to double SPL, in actual principle, a 6 dB gain would occur if you doubled the amplitude (power) of the output signal.
Q5: 94 dB, when the earphones are placed near to the ear the intensity is much greater on the ear drum.
Q6: about one third (1/3) of the total sound power of a 75 instrument comes from the bass drum.
Q7: TRUE, loud noises cause anziety and stress on the body causing the blood pressure to rise and brain to take abnormal activity (that explains a lot!)
Q8: FALSE, the decibel comes from "deci" = ten and "bel" = difference between two intensities.
Q9: most average systems can suffice with 1 F of capacitance for every 1000 W of power, however, for some higher drain systems 2 F is needed for uninterrupted power.
Q10: YES, there is a loudest sound possible, on the decibel scale, a sound could not get any louder (to the humen ear or any measurable device) after reaching....194 dB! which means that dB drag racing could become obsolete if we can somehow manage to squeeze ~20 dB's out of the loudest SPL vehicles! (don't worry, won't be for a long time).
SCORE YOURSELF OUT OF TEN AND GIVE YOURSELF A PAT ON THE BACK!!!
10-14-2004, 01:26 PM
#5
1000 Watt CAFz'r
Join Date: Jun 2002
Posts: 1,242
Actually decibel was named after Alexander Graham Bell. A decibel is just 1/10th of a Bell.
And becuase it is named after someone the proper way to write decibel is dB (note the capital B).
Heres one for you...what is the difference between dB SPL and dB HL
(hint: dB on its own really is a meaningless number)
And becuase it is named after someone the proper way to write decibel is dB (note the capital B).
Heres one for you...what is the difference between dB SPL and dB HL
(hint: dB on its own really is a meaningless number)
10-14-2004, 07:43 PM
#6
Originally posted by JRace:
what is the difference between dB SPL and dB HL
what is the difference between dB SPL and dB HL
Edit, oh ya DB SPL is the level over ambience.
[ October 14, 2004, 08:44 PM: Message edited by: Haunz ]
