Confused about perceived volume differences between same wattage amps !!

riffpowers

I’ve been trying out a lot of different amps lately. 

My findings are - 

jcm800 2204 is much more powerful than any other 50 watt amp I’ve tried. I’ve had it up against a jcm900 50 watt and a jubilee 50 watt and it’s louder than both of them . The 800 on 2 or 3 gives similar volume to the others on 5 or 6. 

So so I want something less powerful than the 2204 . But as not all amps are created equal I don’t know what I should be looking at.

mesa stiletto 50 watt ?? Or is this gonna be too powerful too ? Although some other 50 / 100 watt amps I’ve tried don’t seem to be as unruly as the 2204 . 

Orange 15 or 30 watt ?? 
Jet city 20 watt ??

ICBM

'Unruly' is a good description of a 2204 . They are the loudest 50-watt amps ever made in my opinion.

The Mesa will be much more controllable - not quite as loud at full tilt, easier to adjust with the multiple volumes, and with less of a change in tone relative to volume probably.

As with all of this you're going to need to try it though - we don't know exactly how loud your band plays. Amp power outputs are only a rough guide to final volume, there are so many factors involved that it's impossible to generalise unless you're talking about the difference between say 15 and 50W - and even then you can get a surprise if you compare something like a 15W Matchless Lightning to a "60W" Marshall TSL...

Remember speaker efficiency makes at least as much difference too, you can't really compare the amps unless you're using the same speakers.

ecc83

Subjective loudness also depends upon the "voicing" in the amp. This is the baseline frequency response. Amps rarely have a flat response with the tone pots at 12 o'clock like a hi fi amp or mixer (find Duncan amps Tone Stack Calculator) so, as IC says, it is almost impossible to quantify loudness difference (you can of course MEASURE the power output but even that is a movable feast!) .

Do not, ever go by VC or gain pot positions. That is entirely in the gift of the designer and means Jack. A change of pot 'law' (common mod?) or even ONE extra resistor and the indications go all over the shop but obviously the max POWER output has not change one milliwatt!

Speakers? Yeah, ******G SPEAKERS!

Dave.

John_A

Ironball

Reverend

Nothing else will sound as good so maybe N attenuater?

timmysoft

No.

ICBM

You can also always knock it down to 25W by using a parallel dummy load - just like using two cabinets except that one is silent.

mr-mac

Sensitivity of driver is one thing.  Every 6db is a double of volume so if amp 1 has a driver with 100dB per watt and other has 96dB per watt then that's a large difference.

2nd will be cabinet design.  Open back, closed back etc etc have an effect on how speaker operates if freqs get cancelled out and so on.

the 25w rating can be taken it different THD figures so one may not be useable clean to same volume.

lastly some amps power transformers may be less capable so amp can't keep a constant 25w maybe just peaks

Output transformer efficiency as well.

So answer is can be huge diff in volume between one amp and another rated at 25w biggest aspect will be dB/watt of driver.  Bit add all together and can be huge.  Eg a driver twice as loud sensitivity wise would make a 25w amp perform at same volume as a 100w amp (4x the power in watts to double volume)

mr-mac

You want amp quieter all the time you could swap to a quality driver with lower sensitivity

mark_jwedge

As had been said above I think getting too caught up in ‘how loud this amp A is vs amp B’ is just going to leave you going round in circles. I would just find an amp with the features and sound you want and then ask, ‘is this amp loud enough to gig with in my band, at the type of gigs I play? If the answer is yes then buy that amp and don’t worry about anything further than that

ICBM

At the end of the day you can ask these sorts of questions in as many ways as you want, but all you will get is general guidelines. You cannot tell whether an amp will be loud enough - or even more difficultly, whether it will be *exactly* the right volume so you can crank it - without trying it for yourself. There are too many variables to know anything much more accurately than whether a 5W amp will be enough for a metal band...

Bear in mind that a 15W amp through a 4x12" with V30s will be louder and cut through a mix much better than a 50W 1x12" with a G12T-75 - even assuming all other factors are very similar - and you may get some idea of the problem. And yes, a Matchless Lightning really is louder than a Marshall TSL60.

p90fool

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of velocity.

Expecting all 20w amps to be the same volume is like expecting all 1.5L cars to have the same top speed. 

olafgarten

There are many things that affect volume, wattage is just one of them, and there is no standardised way to measure it.

The wattage is usually the maximum amount of power at a cleanish setting, so the more Overdrive the amp provides the louder it will be. You also have to take into account the speakers efficiency, how many decibels it produces per watt, and this will be different at different frequencies.

You have to also consider the difference between actual and perceived volume. Humans hear different at different volumes even if the dB level is the same. 

mart

p90fool said:

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of power.
...

FTFY

John_A

mart said:

p90fool said:

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of power.
...

FTFY

Think  his analogy was perfect first time, i.e. both the following questions are daft

How loud is a 50W amp?
How fast is a 2000cc car? 

mart

John_A said:

mart said:

p90fool said:

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of power.
...

FTFY

Think  his analogy was perfect first time, i.e. both the following questions are daft

How loud is a 50W amp?
How fast is a 2000cc car? 

The analogy was fine first time around, but missed a beautiful symmetry*. Let me spell it out:

The Watt is a unit of power, not a unit of volume, just like
the cubic centrimetre is a unit of volume, not a unit of power.


* twisted to be even more beautiful by the sneaky pun on volume.

timmysoft

John_A said:

mart said:

p90fool said:

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of power.
...

FTFY

Think  his analogy was perfect first time, i.e. both the following questions are daft

How loud is a 50W amp?
How fast is a 2000cc car? 

How fast is a 50w amp? 

This is my only concern 

ICBM

timmysoft said:

How fast is a 50w amp? 

This is my only concern 

Half as fast as a 100W amp, of course. Don't they teach kids anything these days?

John_A

mart said:

John_A said:

mart said:

p90fool said:

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of power.
...

FTFY

Think  his analogy was perfect first time, i.e. both the following questions are daft

How loud is a 50W amp?
How fast is a 2000cc car? 

The analogy was fine first time around, but missed a beautiful symmetry*. Let me spell it out:

The Watt is a unit of power, not a unit of volume, just like
the cubic centrimetre is a unit of volume, not a unit of power.


* twisted to be even more beautiful by the sneaky pun on volume.

I Wasn’t quite sharp enough, well done

Reverend

timmysoft said:

John_A said:

mart said:

p90fool said:

The Watt is not a unit of volume, just as the cubic centimetre is not a unit of power.
...

FTFY

Think  his analogy was perfect first time, i.e. both the following questions are daft

How loud is a 50W amp?
How fast is a 2000cc car? 

How fast is a 50w amp? 

This is my only concern 

Based on the for sale section here, I'd say about 3 weeks from bought to £60 off for quick sale. 

Bridgehouse

ICBM said:

timmysoft said:

How fast is a 50w amp? 

This is my only concern 

Half as fast as a 100W amp, of course. Don't they teach kids anything these days?

Are you seriously trying to tell us that 100W is twice as fast as 50W? Tut tut @ICBM.. next you’ll be telling us 100mph is twice as loud as 50mph