Help me understand power (watts)

[relsner]

I apologize in advance for newbieness of this question.

I have a Genz Benz 6.0 shuttle and a old GK 800RB. Between the two I really like the GK sound better for what I play. Now having said that, the Genz says 600 watts at 4 ohms, the GK is 300 watts at 4 ohms. Lets say I have an 8 ohm 600 watt 2x10, and an 8 ohm 450 watt 1x15 connected to these amps (not biamped on GK), a combined 4 ohm load right.

All things being equal could I tell the difference in terms of loudness between these amps? I realize PAs come into play in some venues, but taking that out of the equation will the Genz be perceivably louder through the same cab set than the GK? I unfortunately am not in a setting in which I can actully test this due to volume restrictions.

I am wondering if the GK would serve me well enough in small bar venues without pa support in this configuration, or would the 300 watts (per specs anyway) difference be a noticable issue.

Thanks for your comments in advance.

[BassmanPaul]

In order for an amplifier to sound twice as loud you have to increase the output power by a factor of ten. In the case of the GK you would need to go to 3KW. More speakers is always the better way to get more volume. That said you cannot go below the amplifiers specified minimum impedance.

[Windreaper]

Without going into detail, unless your cabs are loaded with premium drivers, you will probably not notice much difference.

[Bass_Pounder]

All else being equal (which it never is), the difference between a 300 watt amp and a 600 watt through the same cabs would be +3db. Not very noticeable.

However, since you are talking about two different brands of amps, all bets are off due to the nature of how each amp is "voiced".

A less powerful amp CAN appear to sound louder than a larger amp depending on which range of frequencies are either enhanced or cut by the amps tone setup.

[CrackBass]

Either amp will deliver the volume you need. Go with the tone you like best.

[Sneakypete]

Think of it like car engines - is a four litre twice as fast as a two litre or can it tow twice as heavy a load? No! You'd have to consider torque, gearboxes and a whole lot of other stuff. Wattage rating is about the poorest specification by which to judge an amplifier and as already stated - extra drivers gives a far better return on your money - you shift more air and your sound is less directional.

[relsner]

Sneakypete, is that to say that I would be better off with (2) 4x10s rather than my 2x10 and 1x15 setup? When does speaker size come into play in regards to moving air?

[Bass_Pounder]

Originally Posted by relsner

Sneakypete, is that to say that I would be better off with (2) 4x10s rather than my 2x10 and 1x15 setup? When does speaker size come into play in regards to moving air?

Size is one of the factors in displacement (how much air the speaker can move).

And in general, yes - you would move lots more air with a set of 4X10's (almost twice as much).

[Sneakypete]

Originally Posted by relsner

Sneakypete, is that to say that I would be better off with (2) 4x10s rather than my 2x10 and 1x15 setup? When does speaker size come into play in regards to moving air?

Just here on TB there have been enough views expressed to fill a very large book on the why's and wherefore's of speaker cabs. My own experience tells me it's better to have more speaker area than rated watts of amplifier output. Coincidentally, I also have a 1x15 and 2x10 with my old bi-amp Trace AH350X. I very seldom use the high-pass channel as the 250W full range is plenty loud enough for anywhere my band plays. The 2x10 is 16ohms (I re-wired it from parallel to series) and rated at 175W, the 1x15 is 8 ohms and rated at 400W. In the unlikely even that I turned the Trace full up the 2x10 would get about 80W and the 1x15 about 160W. This fits in with my opinion that the real handling power of cabs is probably about half the manufacturers stated wattage. Therefore I can turn up with confidence and be sure that I'm not overloading the cabs capabilities. Actually, at the moment I have my eye on a nice s/hand neo 4x10 a bit more up market than the MOR stuff I usually buy. This is rated at 1200W. If I can get it at a reasonable price (probably around £400) then I'll have about the same speaker area but less weight to lug around. I won't sell the old cabs - the 1x15 can go on the high pass channel (150W output) for any outdoor gigs and the 2x10 will be retired to my little home studio. Your setup sounds good to me (on paper at least!) a 300W head that you like the sound of and a couple of cabs is perfectly adequate for most small to medium gigs. If it's not then the rest of the band are too loud! About a million years ago when I first started playing a typical bass amp would be 50W - if you had a 100W head other musos would point at you in the street! A friend who's even older can remember when guitarists and bassists all bought the same amps and cabs because there was no difference between them - now those were the days!

[BurningSkies]

If you really want to understand wattage, and how it relates to amplifiers poke around a bit more here:

Undertanding Power Amplifier Power Ratings

Making Sense of Amplifier Power Ratings

http://www.peavey.com/support/techno.../chapter_4.pdf

Peavey.com

http://www.peavey.com/support/techno...MUCH_POWER.pdf

Peavey.com

[relsner]

BurningSkies thanks for those links, I needs learning!!!

[tech21nyc]

Here is a nice explanation:
http://community.musiciansfriend.com...391?src=3TP1GE