are 15 watts and 40 watts the same volume

Gassage

My Twinolux at the 10w attenuated setting smokes most 40watters. Deep tone at the bttm end! It's so difficult to rate an amp on stats. Ears are better ;-)

Danny1969

I'm using the trusty Blackstar  5 watt tonight in a big 400 person hall so should be able to run it flat out. When these little amps are flat out the clean channel turns into a great crunch channel which cleans up lovely when the guitars backed off. 

For a lot of  modern pro / semi pro  bands .... at least the ones I work with  5 to 10 watts is more than enough as everyone tends to be on ears and they want to protect their hearing for a long enjoyable career in live music. 

For old school bands who enjoy a bit of tinnitus about 40 watts or more should do the trick 

Barney

Danny1969 said:

I'm using the trusty Blackstar  5 watt tonight in a big 400 person hall so should be able to run it flat out. When these little amps are flat out the clean channel turns into a great crunch channel which cleans up lovely when the guitars backed off. 

For a lot of  modern pro / semi pro  bands .... at least the ones I work with  5 to 10 watts is more than enough as everyone tends to be on ears and they want to protect their hearing for a long enjoyable career in live music. 

For old school bands who enjoy a bit of tinnitus about 40 watts or more should do the trick 

5 watts in 400 person hall......surely that must be through a PA system though..?

Danny1969

Barney said:

Danny1969 said:

I'm using the trusty Blackstar  5 watt tonight in a big 400 person hall so should be able to run it flat out. When these little amps are flat out the clean channel turns into a great crunch channel which cleans up lovely when the guitars backed off. 

For a lot of  modern pro / semi pro  bands .... at least the ones I work with  5 to 10 watts is more than enough as everyone tends to be on ears and they want to protect their hearing for a long enjoyable career in live music. 

For old school bands who enjoy a bit of tinnitus about 40 watts or more should do the trick 

5 watts in 400 person hall......surely that must be through a PA system though..?

Oh god yeah Barney, even if you didn't need the volume from the PA it's gotta be mic'ed for your IEM's feed. Tis a surprisingly loud 5 watts though, certainly enough to be heard above the drummer

Barney

Danny1969 said:

Barney said:

Danny1969 said:

I'm using the trusty Blackstar  5 watt tonight in a big 400 person hall so should be able to run it flat out. When these little amps are flat out the clean channel turns into a great crunch channel which cleans up lovely when the guitars backed off. 

For a lot of  modern pro / semi pro  bands .... at least the ones I work with  5 to 10 watts is more than enough as everyone tends to be on ears and they want to protect their hearing for a long enjoyable career in live music. 

For old school bands who enjoy a bit of tinnitus about 40 watts or more should do the trick 

5 watts in 400 person hall......surely that must be through a PA system though..?

Oh god yeah Barney, even if you didn't need the volume from the PA it's gotta be mic'ed for your IEM's feed. Tis a surprisingly loud 5 watts though, certainly enough to be heard above the drummer

haha....i thought i was cracking up then...yeah it seems the way to go with a good pa...

timmysoft

Volume is so dependant on manufacturer. I've relentlessly toured Laney l20h and vc30s but the orange ad30htc just couldn't cut it.

ICBM

timmysoft said:

Volume is so dependant on manufacturer. I've relentlessly toured Laney l20h and vc30s but the orange ad30htc just couldn't cut it.

One big reason for that is the valve rectifier. It's also a poorly designed amp - the standby switch is arranged in such a way as to endanger the rectifier valve every time you use it, and blown ones are common. If you replace it with a solid-state plug-in - just a plain one with no resistors, not a 'valve emulating' one - the problem stops and the amp sounds better as well, it cures the excessive compression and mud when it's really cranked. (And I normally like valve rectified amps.)

timmysoft

ICBM said:

timmysoft said:

Volume is so dependant on manufacturer. I've relentlessly toured Laney l20h and vc30s but the orange ad30htc just couldn't cut it.

One big reason for that is the valve rectifier. It's also a poorly designed amp - the standby switch is arranged in such a way as to endanger the rectifier valve every time you use it, and blown ones are common. If you replace it with a solid-state plug-in - just a plain one with no resistors, not a 'valve emulating' one - the problem stops and the amp sounds better as well, it cures the excessive compression and mud when it's really cranked. (And I normally like valve rectified amps.)

loved the sound of it full tilt, but it just never had enough volume for my band.

Barney

ICBM said:

The difference will be much more noticeable in a mix.

In isolation, two loud sounds both sound loud and it can be difficult to tell how much difference there is. But in a dense mix which is slightly louder on average than the quieter of the two it will struggle to be heard, whereas the slightly louder one is easily audible if it's just louder than the average level. You won't really know until you try it. There's only about 4dB between 15W and 40W, which is not much by itself, but it is if the level you need is 3dB above what the 15W amp will give.

just been thinking about this and im probably miles off but here goes....if there is only 4db between a 15 watt and a 40 watt...will two 15 watts running together be louder than a 40 watt..?

ICBM

It will be the same as a 30W . (2x12", if they're 1x12" each.)

That *may* be slightly louder than a 40W 1x12", depending on the speakers.

Barney

ICBM said:

It will be the same as a 30W . (2x12", if they're 1x12" each.)

That *may* be slightly louder than a 40W 1x12", depending on the speakers.

ahh...ok...it was a bit of a daft question..lol

ICBM

Not really, the relationship between power and volume isn't obvious or even consistent. Most people think the power is the most important factor because its a simple number and easy to understand, but actually speaker sensitivity is more important - and you get a bigger change in effect for a much smaller change in the number... the difference between a 97dB and a 100dB speaker is as much as doubling the power of the amp.

You also gain more volume by increasing the number of speakers, but not very predictably - it depends how close the speakers are to their power rating and hence how 'linear' their response is, and also the cabinet design, but typically you gain about 1-2dB by doubling the number of speakers. It quickly gets difficult to gain more than a few dB that way without impractical numbers of speakers.

So 30W through two speakers may be slightly louder than 40W through one, but only just. If the 40-watter also has a more efficient speaker, it will go the other way.

And that's all before you get into differences in perceived volume due to the different dynamics of various amp designs...

So really there is no easy answer!

Barney

ICBM said:

Not really, the relationship between power and volume isn't obvious or even consistent. Most people think the power is the most important factor because its a simple number and easy to understand, but actually speaker sensitivity is more important - and you get a bigger change in effect for a much smaller change in the number... the difference between a 97dB and a 100dB speaker is as much as doubling the power of the amp.

You also gain more volume by increasing the number of speakers, but not very predictably - it depends how close the speakers are to their power rating and hence how 'linear' their response is, and also the cabinet design, but typically you gain about 1-2dB by doubling the number of speakers. It quickly gets difficult to gain more than a few dB that way without impractical numbers of speakers.

So 30W through two speakers may be slightly louder than 40W through one, but only just. If the 40-watter also has a more efficient speaker, it will go the other way.

And that's all before you get into differences in perceived volume due to the different dynamics of various amp designs...

So really there is no easy answer!

thanks for the info ...its all interesting stuff and answers a lot of questions that i have thought for a while ...im very inquisitive about this kind of thing..

Richardj

So, my Pro Junior sounds better/bigger/louder because the chassis is now in a properly made Blues Deluxe size pine cab and running through two Jensen C10Qs (I could get better speakers, but I already had them). It isn't just me thinking it's louder, it actually is! Clean headroom is still a bit wanting, but is that the real difference in power ratings?

OilCityPickups

These days I'm happy to gig pop/rock with 30 (valve ) watts ... but I miss the sheer luxury of the headroom, foot room and ... er ... just general 'room' of a big amp. Most of my live playing career has been spent with 100w Marshall heads and 4x12s ... and even run at half power, the prodigious amount of air those cabs move shoves your sound into all the nooks and crannies of a venue. To be honest I'm gassing at least a 2x12 again. One popcorn funnel doesn't quite have the projection or sheer 'authority' of two. it makes a real difference now most of what I'm playing is either clean, or just on the edges of breakup ... so a bigger 2x12 combo is on my shopping list ... as well as some industrial strength painkillers for my back.

ThePrettyDamned

TheGuitarWeasel;120500" said:

These days I'm happy to gig pop/rock with 30 (valve ) watts ... but I miss the sheer luxury of the headroom, foot room and ... er ... just general 'room' of a big amp. Most of my live playing career has been spent with 100w Marshall heads and 4x12s ... and even run at half power, the prodigious amount of air those cabs move shoves your sound into all the nooks and crannies of a venue. To be honest I'm gassing at least a 2x12 again. One popcorn funnel doesn't quite have the projection or sheer 'authority' of two. it makes a real difference now most of what I'm playing is either clean, or just on the edges of breakup ... so a bigger 2x12 combo is on my shopping list ... as well as some industrial strength painkillers for my back.

How about the same amp but into a 2x12 cab? You could butcher the amp into a head

Or, my answer to everything, FULL STACK.

Does anyone use a full stack anymore? Last time I saw one was black label society...

impmann

TheGuitarWeasel said:

These days I'm happy to gig pop/rock with 30 (valve ) watts ... but I miss the sheer luxury of the headroom, foot room and ... er ... just general 'room' of a big amp. Most of my live playing career has been spent with 100w Marshall heads and 4x12s ... and even run at half power, the prodigious amount of air those cabs move shoves your sound into all the nooks and crannies of a venue. To be honest I'm gassing at least a 2x12 again. One popcorn funnel doesn't quite have the projection or sheer 'authority' of two. it makes a real difference now most of what I'm playing is either clean, or just on the edges of breakup ... so a bigger 2x12 combo is on my shopping list ... as well as some industrial strength painkillers for my back.

You are right, there is nothing like the sound of a Marshall into a 4x12... but where can you use one these days? All the venues we play either don't have the floor space or they are spl limited, so you can't use them properly.

I used to gig AC30s, two and even three in some venues back in the 90s. Totally ludicrous volume - but sounded incredible and felt amazing. And for me, an original, early 60s Dartford Road AC30 is about the best amp ever made. Trouble is, these days I couldn't even begin to lunk one around, none of the venues we play at would support that sort of volume and the cost of a real one is prohibitive.

But with modern PAs, I honestly can't see the point of an amp much bigger than 40w - even for cleans. Personally, I'm trying to save whatever is left of my hearing...

ChrisMusic

I am curious too, this has been a fascinating discussion so far.

TheGuitarWeasel was pointing out what I would call the "Grunt Factor" or as he eloquently put it "Authority".

How does that factor in to the variables discussed so far, and how do you achieve that "authority" within the SPL limited environments so common nowadays?

Both from a theoretical point of view, and without breaking your bank balance or back in the process.

Is there a psycho-acoustic way of approaching this too?

ThePrettyDamned

This is interesting. It makes me wonder whether a pair of slightly smaller (and therefore portable) amps with a stereo delay pedal to get both running at once would make for a reasonable gigging option, as well as giving you awesome ping pong delay sounds.

Obviously it wouldn't be for everyone, but the idea of a pair of 1x10 combos with 15 watts is easier to carry from the car to the pub than a single 50 watt head and 2x12. Might not give the sound you want but for poppy stuff, blues, and anything that would usually use a slightly pushed power section, it'd be easier than carrying an ac30.

Nerine

I've found that 50w has been the minimum I've been able to get away with. That said, and as others have done, amps aren't created equally.

My CAA is definitely one of the perceived louder 50w amps I've owned..