You do not state whether this is an acoustic or Electric Guitar. An acoustic guitar measures 65 db average to the player's ear. Of course this can vary dramatically, I do not think there is a record for the loudest acoustic guitar but think 80 db is a reasonable estimate.
As far a electric guitar, there is no "real" limit related to electric guitar but rather to sound amplification. A 100W guitar amp can hit 140db. It is easy for a professional level P.A. system to achieve 160 db with good sound quality. It can get louder but at the cost of lower sound quality. Since sound this loud is considered painful and damaging to the listener's hearing, companies don't make systems louder than the "pain threshold" of 155db.
The rock band "The Who" holds the record for loudest rock concert at a sustained 180db. They have since labeled themselves "the loudest rock band" as a result, it could be argued this honor be awarded to the P.A. system not the band.
plucked instrument
Gain, usually measured in decibels, is the ratio of output to input power. A more sensitive amplifier will have higher gain settings requiring less input signal.
A drum kit is no decibels. The decibels depends how close you measure to the bat. The closer - the louder! And the louder you play the more decibels you get. The distance is very important if you measure with a sound pressure level meter.
104 decibels
127 decibels
plucked instrument
The most common decibel used in guitar amps would be 95 and 100 decibels. This would usually be a 60 watt amplifier.
Guitar amps are measured in decibels while speaker output can be measured in watts. The relative wattage or output is not as important as that the sound be heard above the sound of the rest of the instruments in the band.
DeciBels
Power (Watts)/ Decibels (if the speaker is efficient) 2 Watts = 93 decibels 4 Watts = 96 decibels 8 Watts = 99 decibels 16 Watts = 102 decibels 32 Watts = 105 decibels 64 Watts = 108 decibels 128 Watts = 111 decibels 256 Watts = 114 decibels 512 Watts= 117 decibels 1024 Watts = 120 decibels Some Volumes to Compare 10 decibels = normal human breathing 60 decibels = normal human conversation 110 decibels = power saw, car horn, shouting in ear, 120 decibels = jet aircraft close by, emergency vehicle siren, rock concert
do decibels change to wavelength
20 decibels
That would depend on the decibel range output of the amplifier used by it. A very well designed electric guitar itself without an amplifier is barely audible. A small 30W amp will maximize at around 90dB.
207 decibels.
Decibels are a measurement of the loudness of sound.
The usual symbol for decibels is dB.
Decibels