Author Topic: volume vs wattage (Read 5126 times)

hamfist · « **Reply #15 on:** November 20, 2007, 02:39:08 PM »

I have heard it said by those "in the know" that, of the mainstream speaker manufacturers, Celestion rate their speakers the most conservatively.
Just look at the 30W AC30, which traditionally matches beautifully with two 15W rated Celestion Blues.
Even so, in an ideal situation I think one should still be aiming for a speaker cab being able to handle at least 160% of the amp's supposed power output - this is all only relevant if you play your amp anywhere near fully cranked.

If you simply will never play your amp anywhere near fully cranked, then you can get away with much lower rated speakers. For example, I've regularly played a 50W amp through a 30W speaker, but in the full knowledge that I was hitting the speaker with way less than than 30W of power, as I did not have the amp giving up anywhere near even half power.

Alan

HTH AMPS · « **Reply #16 on:** November 20, 2007, 03:06:58 PM »

It really depends on the speaker and the type of signal you're putting through it. You could be safe cranking a 50w head flat out, but add a booster or wah and it might tip it over the edge.

I used to run a 100w plexi flat out with a TS-9 boosting it into a 120w G12H-loaded 4x12, never fried a speaker. In fact, they're still going strong - my mate bought that cab off me around three years ago.

I was really running them on the edge though and taking a risk, but that was the sound I was going for at the time. These days I wouldn't/don't do that as I've since gone through a period of blowing a load of vintage G12H's a year or so back (was getting very expensive).

:twisted:

waves · « **Reply #17 on:** November 20, 2007, 05:14:30 PM »

Quote from: gwEm

only a fool would deny that a valve amp appears louder than a solid state amp of the same rating.

i'm not sure about how much though, and i would be interested in an experiment to determine this.

we pitted a 20W handwired marshall against a 100W AVT and the AVT was noticeably louder. i'm going with a 50w valve amp equates to something like a 125W solid state.... any more ideas on that?

Yeah this time at school a few years ago these two guys battled it out noise wise. A blues guy with a peavey classic 30 (valve) and a bunch of pedals and a metal guy with a line 6 spider 2 150 (solid state).

And as i far as i remember (standing in the room as a keen little minor) all i could hear was the valve amp.

bobthemerciful · « **Reply #18 on:** November 21, 2007, 12:09:12 AM »

20 years ago, armed with formulae provided by my degree-wielding friend and a peak-holding mutimeter I measured the peak output of my AOR 100 into my 200w 4x10 G10 loaded cab. Via an attenuator just to avoid extreme pain!!! I measured the peak output at 170 watts. Speaker efficiency plays a big part in volume also.
Just my two penn'orth. :D

hunter · « **Reply #19 on:** November 21, 2007, 05:48:22 AM »

Loudest amp I have come across was the open backed 2x12 AC30 of my band mate about 15 years ago. I had a 5150 (120W) and a Marshall 4x12 but could hear him better than me.

Guess I used too much distortion and fizz whereas he had lots of mids that cut better.

Roobubba · « **Reply #20 on:** November 21, 2007, 08:24:45 AM »

And loudness as perceived by the human ear is totally frequency dependent. We're evolutionally trained to be alert for the sounds of crunching leaves and breaking twigs - certain higher frequencies (and certain mid frequencies) peak to our minds. Same principle behind why our CDs sound better played louder - then our brains decide they can hear "all" the frequencies, and the music sounds fuller.

Henk · « **Reply #21 on:** November 21, 2007, 09:01:00 AM »

Without making it too complicated, i have always been told that if you half the wattage you decrease the volume by 1/8th. Never found this wasnt correct.

So if you want half the volume from the same speaker(s), and you have a 100w head, youll get this from a ~15watt amp.

Roobubba · « **Reply #22 on:** November 21, 2007, 10:49:01 AM »

Conversely, you'd need an 800W amp to get double the volume of a 100W amp... Ouch!

JDC · « **Reply #23 on:** November 21, 2007, 01:27:28 PM »

got another question now, how much louder is a 4x12 over a 2x12? with an efficient speaker

I'm guessing it's not literally twice as loud

Henk · « **Reply #24 on:** November 22, 2007, 06:47:28 AM »

No its not, you cant predict this because it a parabolic function (power consumption - speaker output). Meaning, at high volume/high watt amp a 4x12 will be alot louder and at low volume/low watt amp the difference would not be that significant.

Hope this is understandable, my tech english isnt very good, my tech dutch is great though :lol:

EDIT: so basically between those two extremes it can make a difference anywhere between 0-50%. For low wattage amps, say about 0-30% maybe? Just best educated guess though.