If I had an amp that say....tops out at 20 watts and I wanted to increase its decibels, could I run 2 20 watt heads thereby increasing the decibels even though both amps are still only 20 watt heads? I am in a debate with an amp snob from a guitar shop who says watts are watts. I believe it comes down to over all decibels at that point. We started this over 50 and 100 watt heads and the noise decibels debate where I explained 50 is not much less then 100 watts due to the decibels. We then went to head room on small amps and wattage. I said to increase head room you could run 2 20 watt heads at once cuz the decibels would be higher and still keep the 20 watt sound of the paticuler amp without going to a different model.
crazy question on decibels.
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DrNewcenstein
He Did the Monster Mash
Re: crazy question on decibels.
2 20 watt amps will multiply your overall volume (dB) by at least 1.5x, and depending on phase cancellation of waves, could go up to 2x. This is a basic physical principle of sound waves. As long as two audio sources do not cancel each other out, 2 is louder than one. This is why 2 people clapping is louder than just 1.
But, I do not think that 2 20 watt miniature amp HEADS, running into the same cabinet (if such a thing is possible), whether it be feeding 2 speakers in the same cab, where each head gets its own speaker, or even both heads feeding one speaker (which leans closer to not being possible), will be louder than just one head.
If you were referring to combos or head+cab setups as just "heads", this may be where the confusion in the discussion is coming from.
Furthermore, you cannot increase the dB of one amp simply by running another identical amp. What you've done in that instance is increase overall dB. If your argument states that you "can increase the dB of an individual amp by running another one", then you are incorrect for this reason, and the amp snob at the store is correct. However, individual amp dB outout and overall dB are two separate concepts.
2 20 watt amps will multiply your overall volume (dB) by at least 1.5x, and depending on phase cancellation of waves, could go up to 2x. This is a basic physical principle of sound waves. As long as two audio sources do not cancel each other out, 2 is louder than one. This is why 2 people clapping is louder than just 1.
But, I do not think that 2 20 watt miniature amp HEADS, running into the same cabinet (if such a thing is possible), whether it be feeding 2 speakers in the same cab, where each head gets its own speaker, or even both heads feeding one speaker (which leans closer to not being possible), will be louder than just one head.
If you were referring to combos or head+cab setups as just "heads", this may be where the confusion in the discussion is coming from.
Furthermore, you cannot increase the dB of one amp simply by running another identical amp. What you've done in that instance is increase overall dB. If your argument states that you "can increase the dB of an individual amp by running another one", then you are incorrect for this reason, and the amp snob at the store is correct. However, individual amp dB outout and overall dB are two separate concepts.
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Van Noord
New member
Re: crazy question on decibels.
Well, if a guy is running at 20 mph, and his friend joins him on the run and is also running at 20 mph, does that mean they are both running 40 mph now....?:no: Just two guys running at the same speed, arriving at the same place, at the same time.
Well, if a guy is running at 20 mph, and his friend joins him on the run and is also running at 20 mph, does that mean they are both running 40 mph now....?:no: Just two guys running at the same speed, arriving at the same place, at the same time.
DrNewcenstein
He Did the Monster Mash
Re: crazy question on decibels.
Two different concepts: speed vs volume.
If two guys have a gallon of beer, and they both pour them into an empty 1 gallon pitcher, one gallon will spill on the table, because of the increase in volume.
If one rattletrap with FLowmasters is idling, and someone starts another rattletrap with Flowmasters, then the volume will be doubled.
Two different concepts: speed vs volume.
If two guys have a gallon of beer, and they both pour them into an empty 1 gallon pitcher, one gallon will spill on the table, because of the increase in volume.
If one rattletrap with FLowmasters is idling, and someone starts another rattletrap with Flowmasters, then the volume will be doubled.
TwilightOdyssey
Darkness on the edge of Tone
Re: crazy question on decibels.
I run two amps into a single cabinet wired as dual 2x12s. I would not say it doubles the overall volume, but it's at least a 50% increase in perceived level...
I run two amps into a single cabinet wired as dual 2x12s. I would not say it doubles the overall volume, but it's at least a 50% increase in perceived level...
crusty philtrum
Vintageologist
Re: crazy question on decibels.
It takes ten times the power to double the volume. Doubling the power will give a 3dB increase, which we percieve as being only a very small increase. In a guitar amp, doubling the power won't sound much louder, but headroom will be greatly increased.
As an example ... if you take a Vox AC15 and an AC30, the 15 won't sound much quieter than the 30, but the 30 will have a lot more clean headroom. If you want to double the percieved volume of the AC15, you'll need to use ten of them.
It takes ten times the power to double the volume. Doubling the power will give a 3dB increase, which we percieve as being only a very small increase. In a guitar amp, doubling the power won't sound much louder, but headroom will be greatly increased.
As an example ... if you take a Vox AC15 and an AC30, the 15 won't sound much quieter than the 30, but the 30 will have a lot more clean headroom. If you want to double the percieved volume of the AC15, you'll need to use ten of them.
Rockstar216
New member
Re: crazy question on decibels.
This. More wattage means more Head room then more volume. A 50 watt head next to a 100 watt head sure the 100 watt will be a bit louder but not by that much but you can push the 100 watter a bit more and will stay cleaner a bit longer. If you want more Vol try more speakers thats what I was told.
This. More wattage means more Head room then more volume. A 50 watt head next to a 100 watt head sure the 100 watt will be a bit louder but not by that much but you can push the 100 watter a bit more and will stay cleaner a bit longer. If you want more Vol try more speakers thats what I was told.
Rodney Gene
O.G.
Re: crazy question on decibels.
You are correct to think in decibels and not watts. There is too much that goes into the end result for a definitive answer. Still with a perfectly efficient speaker cab, a 1000w head is only twice as loud as 100w head, in terms of decibels. Also, some 30w amps are louder than some 40w amps because they have a lower total harmonic distortion rating due to design. Yes, watts are watts and marketing depts. measure watts and sell you watts, but volume/decibels is not due only to watts. I can't provide a greater technical answer, but basic experience with a variety of amp will show you this is true. I'm sure some amp guys can chime in and give you better info. Cheers!
You are correct to think in decibels and not watts. There is too much that goes into the end result for a definitive answer. Still with a perfectly efficient speaker cab, a 1000w head is only twice as loud as 100w head, in terms of decibels. Also, some 30w amps are louder than some 40w amps because they have a lower total harmonic distortion rating due to design. Yes, watts are watts and marketing depts. measure watts and sell you watts, but volume/decibels is not due only to watts. I can't provide a greater technical answer, but basic experience with a variety of amp will show you this is true. I'm sure some amp guys can chime in and give you better info. Cheers!
DrNewcenstein
He Did the Monster Mash
Re: crazy question on decibels.
Hmmm. However, (and no it's not Pick a Fight With Crusty Day), is "power" being defined as merely increasing the wattage applied to one amp (i.e. putting a 200w transformer in a 100w amp, for example), or adding a second identical complete amp (i.e. head+cab or combo)?
Surely two guitarists blasting 100w 4x12 half-stacks is twice as annoyingly loud as just one?
And wouldn't splitting a 4x12 into "two 2x12s in the same cab" running off 2 separate heads introduce phase cancellation, thus resulting in only a 50% increase in volume?
I'd imagine 2 separate 2x12s, even stacked, each with its own head, would result in double the volume as opposed to just one head with one 2x12.
Hmmm. However, (and no it's not Pick a Fight With Crusty Day), is "power" being defined as merely increasing the wattage applied to one amp (i.e. putting a 200w transformer in a 100w amp, for example), or adding a second identical complete amp (i.e. head+cab or combo)?
Surely two guitarists blasting 100w 4x12 half-stacks is twice as annoyingly loud as just one?
And wouldn't splitting a 4x12 into "two 2x12s in the same cab" running off 2 separate heads introduce phase cancellation, thus resulting in only a 50% increase in volume?
I'd imagine 2 separate 2x12s, even stacked, each with its own head, would result in double the volume as opposed to just one head with one 2x12.
Re: crazy question on decibels.
I am talking two 20 watt combo amps being louder then 1 single 20 watt combo amp. To clarify, we were discussing the fender supersonic 22 watt combo. I said you increase decibels and run 2 combos in stereo- left and right-without having to buy the next model up for the 35 to 40 watt decibel level equivalent. You may not have the same head room as 1 60 watt combo but you could still retain the sound of the 6v6 tubes by adding a second combo amp and playing both in a stereo setup. He's saying not really any louder and not worth it.
I am talking two 20 watt combo amps being louder then 1 single 20 watt combo amp. To clarify, we were discussing the fender supersonic 22 watt combo. I said you increase decibels and run 2 combos in stereo- left and right-without having to buy the next model up for the 35 to 40 watt decibel level equivalent. You may not have the same head room as 1 60 watt combo but you could still retain the sound of the 6v6 tubes by adding a second combo amp and playing both in a stereo setup. He's saying not really any louder and not worth it.
crusty philtrum
Vintageologist
Re: crazy question on decibels.
Let's remember that the deciBel is not a unit of ANYTHING ... it is a ratio.
It might also be good to understand that you can have, for example, many types of 50 watt amplifiers, and some will sound a lot louder than others. A bright sounding 50 watt amp will seem much louder than a deep, dark 50 watter because a lot more energy is needed to amplify the bass frequencies (and that is why, in a typical PA system, only a few tens of watts are needed to power the high-end speakers when the bass end of the system needs several hundred watts ... and why a band's bass player will need 400 watts of power to keep up with the guitarist's 50 watt Marshall or whatever).
Two 20-watt combos run in stereo won't sound much louder than just one of those amps used alone, but the spread of the sound will give the impression of a much 'bigger' or 'wider' sound. Put a dB meter in the room and you won't get much of an increase in the reading when the second amp is activated, despite the sound seeming to be much bigger.
Let's remember that the deciBel is not a unit of ANYTHING ... it is a ratio.
It might also be good to understand that you can have, for example, many types of 50 watt amplifiers, and some will sound a lot louder than others. A bright sounding 50 watt amp will seem much louder than a deep, dark 50 watter because a lot more energy is needed to amplify the bass frequencies (and that is why, in a typical PA system, only a few tens of watts are needed to power the high-end speakers when the bass end of the system needs several hundred watts ... and why a band's bass player will need 400 watts of power to keep up with the guitarist's 50 watt Marshall or whatever).
Two 20-watt combos run in stereo won't sound much louder than just one of those amps used alone, but the spread of the sound will give the impression of a much 'bigger' or 'wider' sound. Put a dB meter in the room and you won't get much of an increase in the reading when the second amp is activated, despite the sound seeming to be much bigger.
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DrNewcenstein
He Did the Monster Mash
Re: crazy question on decibels.
My singer used to have a Tubeworks 4x12 with a Fender RocPro1000 head.
I had a Carvin 2x12 cabinet with the same head.
Mine was louder.
My singer used to have a Tubeworks 4x12 with a Fender RocPro1000 head.
I had a Carvin 2x12 cabinet with the same head.
Mine was louder.
SlyFoxx
Glossless
Re: crazy question on decibels.
Crusty speaks the truth.
Just to add to the discussion. There is volume and then there is sound power. A pair of cranked headphones has very little sound power but put close to your ears has quite a bit of volume. A Ted Nugent concert heard three miles away has a ton of sound power but very little volume. It's all about how many air molecules are being moved and how close those air molecules are to your ear.
Crusty speaks the truth.
Just to add to the discussion. There is volume and then there is sound power. A pair of cranked headphones has very little sound power but put close to your ears has quite a bit of volume. A Ted Nugent concert heard three miles away has a ton of sound power but very little volume. It's all about how many air molecules are being moved and how close those air molecules are to your ear.
GoldenVulture
Braindeadologist
Re: crazy question on decibels.
Refer to the table about the number of sources.
- http://www.engineeringtoolbox.com/adding-decibel-d_63.html -
Refer to the table about the number of sources.
- http://www.engineeringtoolbox.com/adding-decibel-d_63.html -
Note! Adding of two identical sources will increase the total sound power level with 3 dB (10 log(2)).
Sound power and sound power level are often used to specify the noise or sound emitted from technical equipment like fans, pumps or other machines.
Sound measured with microphones or sensors are sound pressure.
Adding Equal Sound Pressure Levels
The resulting sound pressure level when adding equal sound pressure can be expressed as:L[SUB]pt[/SUB] = L[SUB]ps[/SUB] + 20 logAdding Equal Sound Pressure Levels Calculator(2)
where
L[SUB]pt[/SUB] = total sound pressure level (dB)
L[SUB]ps[/SUB] = sound pressure level from each single source (dB)
n = number of sources
L[SUB]ps[/SUB] - sound pressure level (dB)[TABLE="class: medium"]
n - number of sources
Sound Pressure Level (dB) : 56
[TR]
[TH]Number of Sources[/TH]
[TH]Increase in Sound Power Level
(dB)[/TH]
[TH]Increase in Sound Pressure Level
(dB)[/TH]
[/TR]
[TR]
[TD]2[/TD]
[TD]3[/TD]
[TD]6[/TD]
[/TR]
[TR]
[TD]3[/TD]
[TD]4.8[/TD]
[TD]9.6[/TD]
[/TR]
[TR]
[TD]4[/TD]
[TD]6[/TD]
[TD]12[/TD]
[/TR]
[TR]
[TD]5[/TD]
[TD]7[/TD]
[TD]14[/TD]
[/TR]
[TR]
[TD]10[/TD]
[TD]10[/TD]
[TD]20[/TD]
[/TR]
[TR]
[TD]15[/TD]
[TD]11.8[/TD]
[TD]23.6[/TD]
[/TR]
[TR]
[TD]20[/TD]
[TD]13[/TD]
[TD]26[/TD]
[/TR]
[/TABLE]
Myaccount876
Amira-Maker
Re: crazy question on decibels.
If you have two HEADS into two SEPARATE cabinets, yes it will be louder as there are more speakers pushing more air, but as to how much louder depends on multiple factors already mentioned.
Also, 100 watts is not twice the power of 50 watts. Double the wattage only gives you a few more decibels, and the decibel scale is logarithmic, meaning 100 decibels is not twice as loud as 50 decibels; 100 dB is actually roughly 665.6x louder (98 dB is 512x louder than 50) than 50 dB. This is because every 6 decibels, the volume is doubled. So 100 dB is twice as loud as 94 dB.
If you have two HEADS into two SEPARATE cabinets, yes it will be louder as there are more speakers pushing more air, but as to how much louder depends on multiple factors already mentioned.
Also, 100 watts is not twice the power of 50 watts. Double the wattage only gives you a few more decibels, and the decibel scale is logarithmic, meaning 100 decibels is not twice as loud as 50 decibels; 100 dB is actually roughly 665.6x louder (98 dB is 512x louder than 50) than 50 dB. This is because every 6 decibels, the volume is doubled. So 100 dB is twice as loud as 94 dB.
beaubrummels
Well-known member
Re: crazy question on decibels.
There's an additional aspect folks sometimes forget. The amp may be advertised as a 50 watt amp, but that may not be what it's actually putting out. A friend of mine had a 1968 50-watt Park that measured 90 watts at the output, while a 100 watt JCM 900 measured 80 watts; presumably due to all the lines outs, effects loops and crap in the modern circuit.
Also, I have a Traynor YBA1 that is rated as an 80 watt amp, but it can output as much as 130 watts according to the documentation. I've noticed first-hand that my Hiwatt 100 doesn't hurt until I dime it, but I can't get past 3 on the Traynor before it starts hurting.
There's an additional aspect folks sometimes forget. The amp may be advertised as a 50 watt amp, but that may not be what it's actually putting out. A friend of mine had a 1968 50-watt Park that measured 90 watts at the output, while a 100 watt JCM 900 measured 80 watts; presumably due to all the lines outs, effects loops and crap in the modern circuit.
Also, I have a Traynor YBA1 that is rated as an 80 watt amp, but it can output as much as 130 watts according to the documentation. I've noticed first-hand that my Hiwatt 100 doesn't hurt until I dime it, but I can't get past 3 on the Traynor before it starts hurting.
y2stevo
New member
Re: crazy question on decibels.
The best way of using "Watts" as a mesurement of how suitable a product will be for a given situation is when you are buying a space heater.
You're right in that when thinking of how loud something will be you should be thinking in dB.
Keep in mind that 99.999% of the numbers used when describing the "wattage" of an amplifier is marketing bull poo, even in the world of pro audio.
But as a rule of thumb (but not getting too technical),
Every doubling of amplifier power results in a 3dB increase in SPL (Sound Pressure Level) at a given distance.
Every doubling of speaker cone area (With equal power applied) results in a 3dB Increase in SPL at a given distance.
As an example.
Say an amplifier is applying a signal of 50watts to a 1x12 speaker. at a distance of 10 meters the SPL meter reads 100dB.
If you then apply 100watts to the same 1x12 speaker, at 10 meters the SPL meter will read 103dB.
If you apply 50 watts to 2x12 speakers, at 10 meters the SPL meter will read 103dB
And if you apply 100 watts to the 2x12, at 1 meter the SPL meter will read 106dB (Since you've doubled both the power and the speaker cone area)
So say for your case you use 2 x 20watt heads each into a 1x12 speaker.
You essentially have a 40watt amplifier into 2x12 speaker so you theoretically have up to 6dB more headroom.
Saying how much headroom an amp or amp setup has is just another way saying how much potential output the amp has before it starts to distort, or breakup. So by increasing the amount of power and/or speaker cone area you will increase headroom.
But keep in mind that increasing speaker cone area will only work to the point until comb filtering (phase cancellations) come into play.
This is a really basic explanation as the physics of sound is much more complicated than simple numbers but hopefully this helps you
I heard a great quote from someone in the pro audio industry that went something like this
"A complex question is easily answered by a simple-easy to understand WRONG answer!"
The best way of using "Watts" as a mesurement of how suitable a product will be for a given situation is when you are buying a space heater.
You're right in that when thinking of how loud something will be you should be thinking in dB.
Keep in mind that 99.999% of the numbers used when describing the "wattage" of an amplifier is marketing bull poo, even in the world of pro audio.
But as a rule of thumb (but not getting too technical),
Every doubling of amplifier power results in a 3dB increase in SPL (Sound Pressure Level) at a given distance.
Every doubling of speaker cone area (With equal power applied) results in a 3dB Increase in SPL at a given distance.
As an example.
Say an amplifier is applying a signal of 50watts to a 1x12 speaker. at a distance of 10 meters the SPL meter reads 100dB.
If you then apply 100watts to the same 1x12 speaker, at 10 meters the SPL meter will read 103dB.
If you apply 50 watts to 2x12 speakers, at 10 meters the SPL meter will read 103dB
And if you apply 100 watts to the 2x12, at 1 meter the SPL meter will read 106dB (Since you've doubled both the power and the speaker cone area)
So say for your case you use 2 x 20watt heads each into a 1x12 speaker.
You essentially have a 40watt amplifier into 2x12 speaker so you theoretically have up to 6dB more headroom.
Saying how much headroom an amp or amp setup has is just another way saying how much potential output the amp has before it starts to distort, or breakup. So by increasing the amount of power and/or speaker cone area you will increase headroom.
But keep in mind that increasing speaker cone area will only work to the point until comb filtering (phase cancellations) come into play.
This is a really basic explanation as the physics of sound is much more complicated than simple numbers but hopefully this helps you
I heard a great quote from someone in the pro audio industry that went something like this
"A complex question is easily answered by a simple-easy to understand WRONG answer!"
