What's the point of 100 watt amps?

[Ch0jin]

I'm no electronics wizard, but I wonder if it may have to do with the output transformer being beefier? There is an interesting article here http://www.legendarytones.com/guitouttrans.html

Funny thing is Robert, being an electronics wizard only gives part of the picture. You'd also need some pretty specific anatomy skills too.

I vaguely recall posting about this here before so apologies if I'm repeating myself, but I'll try to keep it simple.

As our four stringed friends know all too well, the lower the frequency you want to amplify, the more power you need. This applies bass, guitars, home stereo, anything like that. Most people are happy to just accept that as fact (and it is) but the reason behind it has to do with our ears, not electronics.

Our ears are not linear, not by a long way.

If you wan't to prove it, swap an audio taper pot used as volume in something, anything really, and replace it with a linear one. Now sweep the volume through it's range whilst you have some kind of audio signal and you'll very obviously notice that all the volume control seems to be "bunched up" at one end of the control.

How can that be if we use a linear control though?

Simple, our ears, as I mention, are not linear in their response. Not linear in terms of perceived volume; it takes exponentially more and more sound pressure to result in a seemingly linear increase in volume (part of the reason 100W heads are only a little louder than 50W heads, not double. In fact, in terms of perceived loudness, a 100W amp is actually double a 10W amp) and not linear across the Audio Frequency (AF) range from 20Hz to 20KHz.

This last fact is what really causes this whole "more power for bass frequencies" scenario.

If you want loads of technical info, go have a read HERE about Equal Loudness Contours.

The guts of it is that our ears are not so good with low frequency (and if you are my age or older, high frequencies).You need to throw far more sound pressure at them to hear bass guitar frequencies at the same perceived level as guitar frequencies.

So all that proves what we all already know, more power = better bass. Whilst we love to use words like "bottom end" and "thump" and "grunt" and so on, ALL of that is just ways of saying "lower frequencies".

To bring it all back to the specific topic, a 100W amp, with it's ability to generate more sound pressure, will sound "phatter, bassier, ballsier, thicker" because our ears translate that extra low frequency pressure into volume.

I could now dive into the electronic theory as well, but I'm guessing eyes are already glazing over........

[Eric***]

I could now dive into the electronic theory as well, but I'm guessing eyes are already glazing over........

Just about a sentence or two away from doing that, so good timing! Thanks for the info -- I knew the bit about logarithmic power in amps, but not the thing about frequencies.

[NWBasser]

Funny thing is Robert, being an electronics wizard only gives part of the picture. You'd also need some pretty specific anatomy skills too.

I vaguely recall posting about this here before so apologies if I'm repeating myself, but I'll try to keep it simple.

As our four stringed friends know all too well, the lower the frequency you want to amplify, the more power you need. This applies bass, guitars, home stereo, anything like that. Most people are happy to just accept that as fact (and it is) but the reason behind it has to do with our ears, not electronics.

Our ears are not linear, not by a long way.

If you wan't to prove it, swap an audio taper pot used as volume in something, anything really, and replace it with a linear one. Now sweep the volume through it's range whilst you have some kind of audio signal and you'll very obviously notice that all the volume control seems to be "bunched up" at one end of the control.

How can that be if we use a linear control though?

Simple, our ears, as I mention, are not linear in their response. Not linear in terms of perceived volume; it takes exponentially more and more sound pressure to result in a seemingly linear increase in volume (part of the reason 100W heads are only a little louder than 50W heads, not double. In fact, in terms of perceived loudness, a 100W amp is actually double a 10W amp) and not linear across the Audio Frequency (AF) range from 20Hz to 20KHz.

This last fact is what really causes this whole "more power for bass frequencies" scenario.

If you want loads of technical info, go have a read HERE about Equal Loudness Contours.

The guts of it is that our ears are not so good with low frequency (and if you are my age or older, high frequencies).You need to throw far more sound pressure at them to hear bass guitar frequencies at the same perceived level as guitar frequencies.

So all that proves what we all already know, more power = better bass. Whilst we love to use words like "bottom end" and "thump" and "grunt" and so on, ALL of that is just ways of saying "lower frequencies".

To bring it all back to the specific topic, a 100W amp, with it's ability to generate more sound pressure, will sound "phatter, bassier, ballsier, thicker" because our ears translate that extra low frequency pressure into volume.

I could now dive into the electronic theory as well, but I'm guessing eyes are already glazing over........

This is entirely in line with my understanding of these things.

That was an excellent expanation!

[deeaa*]

I too think the transformer may be the reason. I don't know exactly all that the 18/36W switch on my Ceria does, but regardless of volume the difference in low end is really very noticeable, much more prominent than the volume difference.

When I swapped the transformer in my Valve Jr. for a beefier one, that too gave it a whole different low end response and overall it sounded much clearer with the breakup happening only later, here's my video on it:



Also serves as a good example how EMG85's always sound with EL84 amps, more or less...thru a 1x10" Marshall speaker here. My favorite response type :-)

Furthermore, the 120W Ampeg I had, it had so much clean bass end I could easily produce more low end than our bassist...and it had transformer big as a child's head, making the amph weigh like hell...and the reason I sold it. No casters even!

[Ch0jin]

Just quickly because I skipped it before.

YES

Transformers make a difference. Bigger typically means more current handling which means more power which means more perceived low end.

But I think we all kinda already knew that.

[Robert****]

Chojin, you rawk.

Thanks for removing the mud and bringing clarity to this topic!

[deeaa*]

One thing that can have an unbelievably strong effect is also wall proximity, both behind the amp and in front. Bass waves have such a long wavelength that they literally aren't audible in spaces smaller than the frequency demands. Also guitar amps, particularly open-backed Fenders etc. can sound drastically different when placed against a wall/in a corner; especially crunchy sounds can change totally. Battled with these issues a lot gigging in very small venues back in the day, both as a bassist and guitarist.

[NWBasser]

One thing that can have an unbelievably strong effect is also wall proximity, both behind the amp and in front. Bass waves have such a long wavelength that they literally aren't audible in spaces smaller than the frequency demands. Also guitar amps, particularly open-backed Fenders etc. can sound drastically different when placed against a wall/in a corner; especially crunchy sounds can change totally. Battled with these issues a lot gigging in very small venues back in the day, both as a bassist and guitarist.

This is a common misconception. If it were true, then you wouldn't be able to hear any bass in headphones.

The idea that bass waves take space to develop is false. What actually happens is that in a certain point of a room you may get phase cancellations from room reflections leading to the false idea that more space is needed for the sound wave to "develop". The bass sound waves are fully developed right at the speaker.

[deeaa*]

Exactly. You can hear bass in headphones quite OK, but that's a completely different experience from hearing the actual waves in a space where they have room to function...proper low bass will literally cause your heart to try to adjust to its beat...in headphones it's just a faximile...you know this of course from how in a large space a real strong bass will make you literally weak in the knees, even in an orchestra concert...thus any proper mastering studio will be deep enough to allow for true bass reproduction. And yes, the bouncing waves have everything to do with it, it's a science on its own to adjust a room to portray true frequencies as they are...not an easy task.

[Bookkeeper's Son]

..you know this of course from how in a large space a real strong bass will make you literally weak in the knees.......

Are we going to start debating the "brown note" now?

[Ch0jin]

Are we going to start debating the "brown note" now?

Myth Busted. I saw the episode where they tried it.

[cebreez]

Its all about the physics. In the studio you can dub and over dub, pan and fade, or double and delay to your hearts content but it will take some effort on the engineers part to recreate that massive air'ish feedback sound. Even onstage if you mic a small amp it will still sound like a small amp to the mixer. But set a mic in front of a large stack and it will sound like a large stack as it pushes volumes of air and sound towards and around the mic. Just because you point a mic at one speaker doesn't mean thats the only speaker it will pick up. My only point is small amps sound small and big amps sound big. Sounds stupid I know but I love my Peavey Classic 30 112 and the tone I get but sometimes my buddies 212 sounds so much larger even if mine is louder.