are 15 watts and 40 watts the same volume

Barney

ok ...so maybe not but i just tried a blues junior next to my hotrod deluxe and there dosnt seem to be loads of difference and same with my 100 watt head and 40 watts hotrod deluxe...so is it really just how much clean headroom we get ..?...im listening to the blues junior and reckon i could use it with a live band..?

ThePrettyDamned

There is a fair bit less difference than people think, but you'll be amazed at how quickly that Blues Jnr will break up when competing with a drummer.

Wattage is just a power rating.  Volume is more to do with perception (we hear some frequencies better than others, why a 15 watt bass amp is never going to compete with a 15 watt guitar amp) and sound pressure level.  

Speaker efficiency helps, too.

jd0272

I can gig my Laney LC15R wee valve combo thru the 4x12 no bother, and we've a noisy drummist.

ICBM

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.

It also depends on the type of sound you want - if you're aiming for a narrow, mid-focused sound then a lower-powered amp will hold its own better against a broad mix than if you want a deep, open sound - then you need more power, even to get the same apparent volume. This is even more true with clean sounds than overdriven ones, and there's a huge difference between the two. Just to get the same volume with a strictly clean sound that you can achieve with an overdriven 15W amp, you'll probably need at least 60W, assuming similar speakers. More powerful amps also project better and fill a space more easily even when they're not turned up any louder - this may be what you want, or it may not if you're mic'ing up and trying to keep spill down.

Some people certainly do find a 15W 1x12" enough in a band mix… others find they need a lot more power even to play at what seems like about the same volume. If you have both amps, try the BJ with the band and then you'll know. If you don't, make sure you try one before you give up your Hotrod to get it.

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 15W.

It also depends on the type of sound you want - if you're aiming for a narrow, mid-focused sound then a lower-powered amp will hold its own better against a broad mix than if you want a deep, open sound - then you need more power, even to get the same apparent volume. More powerful amps project better and fill a space more easily even when they're not turned up any louder - this may be what you want, or it may not if you're mic'ing up and trying to keep spill down.

Some people certainly do find a 15W 1x12" enough in a band mix… others find they need a lot more power even to play at what seems like about the same volume. If you have both amps, try the BJ with the band and then you'll know. If you don't, make sure you try one before you give up your Hotrod to get it.

yeah i think i understand this and its in line with what iv found really....just at home there was no neighbors in so got the chance to try them side by side and there didnt seem a lot of difference even with the 100 watt head......the head had more depth and obviously more vol but not that much more..i did try a 15 watt laney at rehearsals a while back and it was a bit low on volume for what we were doing ,,but at home they sound similar..saying that i have a mk4 boogie and thats definitely louder than the 100 watt head...i think its rated at 80 watts...

ICBM

Amps do vary a bit in volume even for the same rated power - the design of the power stage and the voicing can change the perceived volume even if the rating is accurate (which it isn't always).

Mark series Boogies are notoriously loud for their ratings - they're very mid-focused and 'tight' so they really punch through, and they have very efficient speakers. I had an original Mk1 in the shop a while back with an EV in it and it was like a jet engine in a confined space - literally painful, fully cranked. They're also extremely directional so they really concentrate all the volume into a narrow beam right in front of them, which makes them even louder if you are.

Barney

yeah i Put a EV in the mk4 ...i think they work great with them amps...

Gassage

I know that a 100w amp is about 3db louder than a 50w!!

Fusionista

+1 and a wisdom for Icey

ICBM

Gassage said:

I know that a 100w amp is about 3db louder than a 50w!!

Absolutely true, and some people take that to mean that there isn't much difference. (There's another myth that 3dB is about the minimum volume difference you can hear - which may be true in isolation without a direct A/B, but it definitely isn't in a music context.)

Saying that a 100W amp is not much louder than a 50W amp because it's only twice the power is like saying that a Porsche 911 is not much faster than a VW Beetle because it only has twice the top speed. It's technically true, but it doesn't give the full picture of how it responds in use .

Barney

Some great advice here.....so what's the minimum size amp to play live with ...needing a fair bit of clean headroom but not loads...the least I have was the hotrod deluxe ..I manged ok with that one but liked the extra vol if needed out of the boogie...cos you don't really know the room until you switch on....I have a feeling the 15 watt won't be enuff for me but I will try it....

ICBM

Doesn't the MkIV have a 15W setting? ("Class A")

If so, try that - if it's not enough, the BJ definitely won't be since the EV is more efficient than the Fender speaker. I know that will make it the world's heaviest 15W amp, but you only have to try it once .

For what it's worth I used my Blue Angel in 15W mode quite often, but only when I wanted that slightly overdriven sound - it wasn't loud enough for cleans even at the fairly low volume I play. I miss that amp . Selling it to a friend was one of my less brilliant decisions, but at least I know where it is...

impmann

Ok all these decibel ratings assume you are running flat out. If you are running a 100w valve amp in a pub or club flat out then you are either deaf or daft...
Our band (very loud Punk tribute band) has two guitarists and we currently don't mike up. The other guitarist has a Hayden Mofo 15w through an old Marshall 2x12cab - and he's pretty much on the limit of what the amp can deliver. I'm running a Sessionette 75 with a Line6 M13 taking care of drives - and I'm running normally on about 25%. Plus for solos I have acres of headroom, whilst the other guitarist struggles to be heard for his, depending on the venue.
However, in the new year the plan is to invest in a bigger, better PA and mike up. Therefore, I'm going 'down' to a similar 15w valve amp to match the other guitarist and keep on stage volumes down. This gives a better sound, more control and makes it easier when landlords need us to turn down due to residential complaints (it happens).
So to answer the question, it really depends on what you are playing, how your band's PA is set up and the sizes of venue.

monquixote

Even with amps of the same wattage rating it's largely meaningless. 

I've owned three 20w(ish) 1x12 amps

The Blackstar HT-20 had no clean at gig levels and ran out of puff for solos.

The Supersonic 22 had plenty, but the clean started to get a bit gritty at bigger venues and it wasn't quite enough for festivals.

The H&K Puretone is just head crushingly loud. I did a dep gig in a band where the other guitarist was using an HT-100 and 4x12 and he asked me to tone it down a bit as I was drowning him out and I was barely off the backstop on the volume.

Gassage

Barney said:

Some great advice here.....so what's the minimum size amp to play live with ...needing a fair bit of clean headroom but not loads...the least I have was the hotrod deluxe ..I manged ok with that one but liked the extra vol if needed out of the boogie...cos you don't really know the room until you switch on....I have a feeling the 15 watt won't be enuff for me but I will try it....

Gosh, what a difficult question, to which there's many answers!

Neil Young has played 'Enormodromes' for years using a 30w Deluxe! But then factor in it goes thru a massive PA type thing aptly called a Baldwin Exterminator and has 2 x 15's, 4 x 12's and 2 x 8's in it!!

Johnny Marr's main live amp is a 22w DRRI.

Many have used the AC30, which is a deafening 30w, and equally, I find 135w Ultra Linear twins to be relatively (!) quiet for their behemoth power.

Clapton gigs stadia with his 40w Twinolux, Gilmour would use 6 x DR103's, 16 12" speakers and 8 doppola speakers, with a deafening 600w total for the same gig.

Also, bear in mind that this is about 'moving air' and speaker config will be crucial. Generally 10" move less air, but are punchier. I'd always have 2 x 10" whereas you can get away with 1 x 12" (although 2 is always better). 8" are not really big enough, unless you've got maybe 2 x 8" and a 1 x 15" underneath. 15" are not to be used alone; too flabby and lack definition, great when mixed with 10's or 12's.

So the answer to your q would be down to other criteria, such as mic'ing, PA facilities and much more, and importantly, what you are competing with in your own band (eg another guit player, keys etc need more ooomph IMO, in a power trio you could get away with less.)

I would suggest that a nice modern gigging range is 20w-40w. I find the Blues Jr to be just lacking (prob down to speaker size and 'moving air'), the DRRI to be a good benchmark minimum (esp with an extn cab) and a 40w to be perfect.

Sorry if it's not a definitive answer, but my tuppence worth and hope it helps.

Barney

ICBM said:

Doesn't the MkIV have a 15W setting? ("Class A")

If so, try that - if it's not enough, the BJ definitely won't be since the EV is more efficient than the Fender speaker. I know that will make it the world's heaviest 15W amp, but you only have to try it once .

For what it's worth I used my Blue Angel in 15W mode quite often, but only when I wanted that slightly overdriven sound - it wasn't loud enough for cleans even at the fairly low volume I play. I miss that amp . Selling it to a friend was one of my less brilliant decisions, but at least I know where it is...

yeah it has...never thought of that.....in fact i havnt really used the triode /pentode /simulclass much ...i should maybe experiment a bit with all that stuff....i just found i got the fullest sound with pentode full power....not just for volume it just seemed bigger and cleaner....i think i need to experiment a bit

Barney

Gassage said:

Barney said:

Some great advice here.....so what's the minimum size amp to play live with ...needing a fair bit of clean headroom but not loads...the least I have was the hotrod deluxe ..I manged ok with that one but liked the extra vol if needed out of the boogie...cos you don't really know the room until you switch on....I have a feeling the 15 watt won't be enuff for me but I will try it....

I would suggest that a nice modern gigging range is 20w-40w. I find the Blues Jr to be just lacking (prob down to speaker size and 'moving air'), the DRRI to be a good benchmark minimum (esp with an extn cab) and a 40w to be perfect.

yeah ...from what iv tried 40 watts sort of works for me , blues junior sounds great when turned up but maybe will be lacking with the band ..i will have to try..:) it was just the side by side comparison that confused me a bit with the volumes , i ICBM has explained about it being different in a band situation.....i love using the boogie but im getting old and its getting heavier...lol

monquixote

What I've noticed with smaller amps like the BJ is that as you wind them up to gig volumes all the low end starts to go and they sound very boxy.

ThePrettyDamned

I think, if it doubt, the hot rod deluxe can do everything. Home practice or gigging, any style (seriously, it does pretty well with heavier styles with a good pedal). It has enough volume for acceptable results and a nice tone, and takes preamp type pedals nicely, too.

That doesn't mean it's the right amp for you, but if you are ever in trouble, as a reference, it's the go-to for tons of gigging bands out there in a variety of styles, and doubles as a home practice amp.

monquixote

There is a reason the HRD is the most popular amp in the world.

Drew_TNBD

It's all to do with tone, as other people have said. There are very few 50-watt amps that I have enjoyed playing, compared to the 100-watters, and it's nothing to do with volume. It's the low-end... they're just different.

EVH5150III 50-watt is one of the lower wattage amps that I actually do really like.