Approximately how much louder is 85w. compared to 30w.

[Sonex Reducer]

Lets say you have a 30w. solid state head and a 85w. solid state head. Is the 85w. going to be much, much louder? I'm thinking it wont be. Approximately how many more decibels?

I ask because I usually bring my 85w. head and 2x12 cab. to practice, and I'm wondering if I will be heard in the mix If I bring my more back friendly marshall 30w 2x12 combo. Go ahead and rip on SS Amps here if you feel like it, I've heard it all and it don't bother me none.

Thanks.

 

[Bigsby'd]

Too many variables for ANYONE to answer. There are many situations where a lower powered amp is percieved as louder.

 

[bbutler123]

Lets say you have a 30w. solid state head and a 85w. solid state head. Is the 85w. going to be much, much louder? I'm thinking it wont be. Approximately how many more decibels?

I ask because I usually bring my 85w. head and 2x12 cab. to practice, and I'm wondering if I will be heard in the mix If I bring my more back friendly marshall 30w 2x12 combo. Go ahead and rip on SS Amps here if you feel like it, I've heard it all and it don't bother me none.

Thanks.

30 watt 2x12? I've never heard of that. Is it solid state also? I thought the only SS Marshall 30 watt was 1-10" or 1-12" at most.

Different companies rate watts differently(they shouldn't) . But if the speakers are the same sensitivity in both amps, I think the 85 would be definitely louder, but compared to how loud either amp is at that point, the DIFFERENCE might not be all that great.

A bigger difference might be how long they'll stay CLEAN when you turn them up.

P.S. I've owned a number of Marshall solid state amps, and I have the greatest respect for them. They don't have as much 'color'/'dimensionality' as tube amps, but they DO sound like a Marshall.
My favorite was the 50 watt 1x12", I think. The 100 watt combo with 1-12" was VERY loud (I was impressed). I had a couple 100 watt heads with 1/2 stacks too. And they were in the ballpark with the 100 watt tube halfstacks. What I mean by that is, as you turned it up to the high ranges, your being starts thinking 'Is this really a good idea?..."

 

[Sonex Reducer]

30 watt 2x12? I've never heard of that. Is it solid state also? I thought the only SS Marshall 30 watt was 1-10" or 1-12" at most.

Different companies rate watts differently(they shouldn't) . But if the speakers are the same sensitivity in both amps, I think the 85 would be definitely louder, but compared to how loud either amp is at that point, the DIFFERENCE might not be all that great.

A bigger difference might be how long they'll stay CLEAN when you turn them up.

thanks. it's a 1979 master lead combo. they made 100w. and 30w. versions in the 70's.

 

[SteveGangi]

85 Watts is 2.83 times more power than 30 Watts, or 4.5 dB more power. So it should be perceptibly louder, given all other things being equal. But you also have to consider the efficiency of the speakers. They can vary wildly.

Additionally you need to consider whether it is an open or closed back cabinet. A closed cab should be "beamy" or directional - louder in the front and much quieter in the back and more. Finally, it really only matters if you have to crank it, and for MOST places you don't have to.

It takes about 1 dB to be a perceptible loudness difference for most people.

 

[Sonex Reducer]

thanks. yeah, it's open back and i thought about that... i'm only thinking of using it for rehearsal, should be fine.

 

[tolm]

Whenever I've looked into this sort of thing I always wind up back at the "100W is twice as loud as 10W which in turn is twice as loud as 1W" argument - which I will wildly assume is true for solid state as well as valves.

That being said, Guitarist magazine did a 'decibel-off' and a 30W AC30 was louder than a 100W Marshall so clearly efficiency, frequency response, etc are key.

I would imagine the 85W'er won't be 'that much' louder but would give you more clean headroom before the diodes start clipping: which on solid state is surely a good thing?

 

[freebyrd 69]

Depending on the venue, it should be about 55 watts louder.

 

[QReuCk]

To Tolm: yes an AC30 is a helluva loud amp (I know I have to "compete" with one in my band). But it is a tube amp and ratings are usually made without exceding a certain amount of harmonic distortion. So essentially, tube amps can be a lot louder than their ratings when not clean and how much louder they can get from the rated power is highly variable from one model to another.

To OP:
As far as SS amps are concerned, they usually tend to not be able to go that much higher than their rated power (once the signal hits the power rails, it hits them and can't go any higher than that). So we can assume there is less difference in output power of the amp from one SS model to another provided they are rated RMS and not peak power. Even the THD doesn't change that much the readings as they tend to be dead clean under clipping threshold.
But, the marshall is a combo and the 85W head runs through a cab. This will make a difference, which can be more than the 4.5db difference in output power... in one way or the other.

By the way, I don't need the 9db boost of my Trademark 120 to play with 2 drummers, a guitarist with an AC30 and a saxophonist, so I have 120W -9db = 15W in a 2x12'', all solid state. It is still louder than my Peavey Envoy 110 (40W in a 10'', still usable for rehearsals with this band if I don't want to carry the big thing).
I would guess unless the drummer is a really heavy hitter, 30W in a 2x12 will work fine for rehearsals if the speakers are anygood.

 

[BluesRock]

At the risk of sounding like a smartass... why don't you just bring both to rehearsal and try the 30W. If it doesn't cut it switch to the 85W and keep rehearsing. Either way, you will know the answer.

 

[dspelman]

Lets say you have a 30w. solid state head and a 85w. solid state head. Is the 85w. going to be much, much louder? I'm thinking it wont be. Approximately how many more decibels?

All else equal, double the power (60W) will only give you 3 dB more output. Another 3 dB will require doubling the power again (to 120W)

3 dB is, on average the smallest noise level change that can be detected by the human ear. 6-10 dB will give you double the static air pressure level ("double the volume," if you will), but whether the ear will actually HEAR double the volume depends on the frequency at which that 10 dB is applied. 10dB requires approximately 10X the power (a 50W amp will provide 10dB more output than a 5W amp).

 

[Sonex Reducer]

At the risk of sounding like a smartass... why don't you just bring both to rehearsal and try the 30W. If it doesn't cut it switch to the 85W and keep rehearsing. Either way, you will know the answer.

because i'm driving my wife's Hyundai. it's cramped in there.

thanks for all the "solid" replies guys. i've actually learned a lot from this thread. diodes clipping? cant wait to hear 'em chirp! right...

anyways, the 30w has really cheap speakers in it i think, never been able to crank it, who knows, maybe they'll sound great.

 

[jtees4]

Can't give you a number, but it will be louder. Not crazy louder, just a little louder.

 

[nauc]

x2 the power = a 3db gain

x2 the speakers = a 3db gain

a 10db gain = sounds twice as loud

for the most part

 

[Sonex Reducer]

x2 the power = a 3db gain

x2 the speakers = a 3db gain

a 10db gain = sounds twice as loud

for the most part

according to this, it would be about half as loud in the room. (open cab). the thing is, headroom will be missing.

 

[SteveGangi]

because i'm driving my wife's Hyundai. it's cramped in there.

thanks for all the "solid" replies guys. i've actually learned a lot from this thread. diodes clipping? cant wait to hear 'em chirp! right...

anyways, the 30w has really cheap speakers in it i think, never been able to crank it, who knows, maybe they'll sound great.

That may be something to think about - speaker efficiency. That can be a biggy.

 

[River]

Such a wonderful little forum we have here. Yet so few people seem to actually READ the posts in it.

Dude, take your amp to practice and tell us what you perceive. What you perceive is all in your head, not on some spec sheet. We'd love to hear your take on it, but we can't predict it.

 

[AngryHatter]

I thought about the question and my conclusion is six. It will be perceived as six times as loud.
Check my work below.

 

[River]

Check my work below.

Calculus always made my head hurt. I think I'm ready for it now, but don't know if I'll ever know. Hard to care about predicting the future when you're already living in it.

 

[nauc]

Calculus always made my head hurt. I think I'm ready for it now, but don't know if I'll ever know. Hard to care about predicting the future when you're already living in it.

youre living in the "future"?...