Marvel Posted October 1, 2004 Share Posted October 1, 2004 We could convert everything to horsepower and go from there. One horsepower is equal to 746 watts. Marvel Quote Link to comment Share on other sites More sharing options...
jfmacken Posted October 1, 2004 Share Posted October 1, 2004 What's the fuss about all of this perceived loudness? The key word here is "modality". The way one person responds to a stimulus is never going to be exactly the same as another. There is no way to measure which increase in sound pressure is twice as loud simply because twice as loud is impossible to define in such a generalized manner:) Quote Link to comment Share on other sites More sharing options...
WMcD Posted October 1, 2004 Share Posted October 1, 2004 I must say that my experience is quite different than what D-Man reports. The dB scale on electrical power and the dB SPL do track exactly. I do acoustic measuring with an LMS system which is pretty much an industry standard. I find that 2.82 volts (1 watt nominal) on the home make K-Horn is too loud. So I use 0.89 volts, which is 0.1 watt and the response is 10 dB down. Using 0.282 volts is 0.01 watt and is 20 dB down. This is with a Wavetek electrical meter. Even if meters are not "true RMS" they are bound to be correct with a sine wave. Best, Gil Quote Link to comment Share on other sites More sharing options...
djk Posted October 2, 2004 Share Posted October 2, 2004 Meters on amplifiers are almost worthless because of the log function of our ears. McIntosh has a log setting on most of their amplifiers so that you can actually see the meters move at low volume on efficent speakers. The markings are linear and spaced 10dB apart. The meter starts moving at about 100µW and the first division is at 1.2mW, with a division every 10dB up to a rated 120W out. http://berners.ch/McIntosh/Images/MC2125_Front_01.jpg Quote Link to comment Share on other sites More sharing options...
formica Posted October 4, 2004 Share Posted October 4, 2004 ---------------- On 10/1/2004 3:41:30 PM D-MAN wrote: This gets especially confusing for me... ---------------- yes... ---------------- For example, 3W reference +10x wattage = 30 Watt = twice as loud from 10x the power or +3db, or one increment on the meter... +3db increase in SPL is twice as loud as the reference level(0db). This is acoustical level of signal only... 10 times the reference ELECTRICAL WATTAGE (current*voltage) will result in a +3db ACOUSTICAL signal level change, which is exactly TWICE as loud as the reference acoustical level ---------------- Ummm... you shouldn't doubt Gil. Still the same as last time... - 2x Watts = Double the Power (ie: 1watt to 2watts) = 3db increase - 10x Watts = Ten times the Power (ie: 1watt to 10watts) = 10db increase And the often stated (but only for RELATIVE comparison in my opinion) are: 3db increase is noticeable to all people as being louder but NOT double 10db increase is often refered to twice as loud by many people later... Rob Quote Link to comment Share on other sites More sharing options...
D-MAN Posted October 4, 2004 Share Posted October 4, 2004 Rob, you're right, +3db SPL is the point at which most people detect a change in volume. It is not twice as loud. I appologize for adding to the confusion. DM Quote Link to comment Share on other sites More sharing options...
DrWho Posted October 4, 2004 Share Posted October 4, 2004 ---------------- On 10/4/2004 11:01:14 AM D-MAN wrote: Rob, you're right, +3db SPL is the point at which most people detect a change in volume. It is not twice as loud. I appologize for adding to the confusion. DM ---------------- lol +1dB is the point at which people detect a change in volume; aka that's the smallest change a human can detect. At least that's how the decibel was defined way long ago (or so my text book tells me). My text book also tells me that 3dB is a doubling of power, but 6dB is percieved as a doubling of loudness (though i've heard the 10dB remark from many people as well). I've always considered 3dB to be a noticeable difference. 1dB is very hard to hear, especially with music. 2dB, well you never see that anywhere so nobody cares (i'll go so far as to claim that 2dB is less noticeable than 1dB, lol). When it comes down to it, if the method of attenuation isn't capable of at least +-6dB (a bandwidth of 12dB), then you're really limiting yourself in what can be done thought the attenuating (though depending on the case, it may not be as big of a deal) Quote Link to comment Share on other sites More sharing options...
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