Probably sounds dumb but...

[organworthyplayer337]

When I read the title I read your username at the same time; "Probably sounds dumb but.... I need a six..."

 

[hrodbert696]

Can't help but think that a lot of these responses are way more complicated than what the OP wants to know. The essential information has been posted a couple of times but buried in detail.

The fundamental thing the OP needs to understand is that the head's rating is power output, the cab's rating is how much power it can handle. The cab doesn't produce any power on its own. He seemed confused about that.

A 200-watt head into a 1200-watt cab will give you 200 watts. The head puts it out and the cab can easily handle that. A 2000-watt head into a 1200-watt cab will blow it up - more power than it can take.

Understanding impedance and all the rest is important but that's the first, fundamental point.

 

[Robroy]

So I'm wondering, with amp heads and cabs, why does the head have specified wattage? I'm confused because if the head is 200 watts and it's run through an 8x10 1200 watt cab, what's that mean?

It means the amp won't blow that cab.

Amp power rating is how much power the amp produces at a particular impedence and with a specific amount of distortion. Speaker power is how much power an amp can pump into it before it is damaged. A 2 watt amp can power a 2,000 watt speaker just fine. It will get as loud as 2 watts can drive it. But if you want it to get as loud as it can, you can push a 2,000 watt amp into it. Push a 3,000 watt amp into it and it will probably fail.

BTW, An amp that sez it produces 100 watts with .01% distortion may produce 200 watts with 10% distortion. So you have to consider how much power the amp will actually pump into your speakers when you turn it to eleven.

 

[jthisdell]

When I read the title I read your username at the same time; "Probably sounds dumb but.... I need a six..."

When read like that it does not sound dumb at all!

 

[EastCoastThump]

A 200-watt head into a 1200-watt cab will give you 200 watts. The head puts it out and the cab can easily handle that.

Well, it'll give you between 0-200+ watts, depending on amp design, input, levels of distortion, and settings—potentially considerably more than 200 watts.

A 2000-watt head into a 1200-watt cab will blow it up - more power than it can take.

A 2000-watt amp *can* be run safely into a 1200-watt cab. You just can't heedlessly run a large amp into a cab with foolproof safety; but the key is to be neither heedless nor foolish about it.

I've frequently gigged a 2000-watt Stewart amp into a Schroeder 21012 (rated for 1000 watts). I've also gigged the Stewart into various cabs rated from 200-400 watts without problems. As you're getting used to how a particular amp pairs with a particular cab, listen carefully. If it sounds like you're stressing the cab, dial back the amp. Once you get used to what your rig can do, stay within your cab's limits and resist the temptation to dime the amp if you know the cab won't take it.

 

[JollySpudd]

Right, that's not an issue( yet ) but is there a specific advantage to a head with greater wattage? If your running through the same cab and power levels Aren't an issue. For example let's say I have a 200 watt head run through a 1200 watt Cab ( that thing would be huge ) what advantage if any would I get by trading out to a 500 or 1000 watt head?

The way I understand it, the advantage would be cleaner signal at higher levels. So long as the speakers can handle it . Pushing a lower powered head too much for more volume will result in more general distortion of your input signal, which your higher wattage cab would reproduce nicely, as your amp gradually moves toward toast from being pushed passed its power limits.

A higher powered amp, when used wisely, with a good power handling cab, even of lower power handling than the amp puts out, will deliver more cleaner signal. High volumes should never be abusive. Aim your cab at your head, not your knees, like so many guitarists unfortunately do - and let wisdom help mix your stage / rehearsal levels with line-of-sight speaker directionality. Use a DI or mic to make up the difference a tad for everyone else.

Point being, high volume playing to the point of possibly damaging amp, speakers and hearing, is unnecessary these days. - A powerful enough amp to cleanly service a good cab will do the trick with less potential for damage all around. Unless high volume for no good reason makes one foolish.

Your career will last longer.

 

[I Need a six...]

Can't help but think that a lot of these responses are way more complicated than what the OP wants to know. The essential information has been posted a couple of times but buried in detail.

The fundamental thing the OP needs to understand is that the head's rating is power output, the cab's rating is how much power it can handle. The cab doesn't produce any power on its own. He seemed confused about that.

A 200-watt head into a 1200-watt cab will give you 200 watts. The head puts it out and the cab can easily handle that. A 2000-watt head into a 1200-watt cab will blow it up - more power than it can take.

Understanding impedance and all the rest is important but that's the first, fundamental point.

Well yes it was all buried in detail, but i actually asked specifically for as much detail as possible so that's not more than I asked for

 

[I Need a six...]

The way I understand it, the advantage would be cleaner signal at higher levels. So long as the speakers can handle it . Pushing a lower powered head too much for more volume will result in more general distortion of your input signal, which your higher wattage cab would reproduce nicely, as your amp gradually moves toward toast from being pushed passed its power limits.

A higher powered amp, when used wisely, with a good power handling cab, even of lower power handling than the amp puts out, will deliver more cleaner signal. High volumes should never be abusive. Aim your cab at your head, not your knees, like so many guitarists unfortunately do - and let wisdom help mix your stage / rehearsal levels with line-of-sight speaker directionality. Use a DI or mic to make up the difference a tad for everyone else.

Point being, high volume playing to the point of possibly damaging amp, speakers and hearing, is unnecessary these days. - A powerful enough amp to cleanly service a good cab will do the trick with less potential for damage all around. Unless high volume for no good reason makes one foolish.

Your career will last longer.

Ok so here's the last bit I'm
Not quite sure about. If you have a 1000 watt amp, and run it through TWO 600 watt cabs, is that safe as the total is 1200 watts? or are you risking cab Damage as the individual cabs are each 600 watts?

 

[waltdogg]

You are safe. But just barely, each cab will be seeing 500 watts each at FULL CLEAN POWER.

 

[I Need a six...]

You are safe. But just barely, each cab will be seeing 500 watts each at FULL CLEAN POWER.

Thanks guys! I'm totally getting it now. Now what's the diffence between tube and Ss watts? Haha no i'm just kidding, no Need to open that can of worms here! It's been hashed out like a hundred times!

 

[DreadyDiggs]

My amp Hartke LH1000 is an amp with 2 500watt channels.

In bridged mode with a single 4 ohm cab the amp will push 1100 watts. In bridged mode with a single 8ohm cab it will push 750 watts.

I use it with two 8 ohm cabs in bridged. They are older with no speakOn connections, so I just use the reagular jacks. If I tried to update them I would end up blowing them. With my setup I do not know how much it pushes but it is enough to damage them as I believe the cabs are rated for only 350 watts or so.

I have done no damage to them because I cant reach anywhere near full power without being told to turn down haha. They are loud enough to do just fine as is.

I do plan to get an 8x10 4ohm cab, but honestly have no need for it.

Basically, buy as small (wattage wise) an amp you can afford that effectively pushes your cab(s) to the volume you need without distortion or damage to the cabs.

I bought my stuff used as a package deal and I love the amp.

 

[wintremute]

I'm glad OP asked this question. I learned a lot.

 

[EastCoastThump]

You are safe. But just barely, each cab will be seeing 500 watts each at FULL CLEAN POWER.

This would keep the cabs safe (in the sense that you wouldn't need to worry about damaging your drivers no matter how you run the amp) *if* the amp's rated wattage (at whatever low % of THD for which it is spec'ed) represented its full *possible* output. But that isn't how amplifier wattage ratings work. As discussed above, it's typically possible to drive an amp beyond its nominal power rating by driving it into higher-than-rated levels of THD.

It's possible to safely use an amplifier with a (much) higher wattage rating to drive a cabinet with a lower wattage rating. It's also possible to blow drivers by inattentively pushing an amplifier, even if that amplifier has a wattage rating lower than the cabinet. For those reasons, the best way to avoid blowing speakers is to attend to how your rig's pieces work together, and to learn to recognize the way your cab behaves as it's getting pushed near its limits.

 

[Downunderwonder]

Pretty much sums it up.

However, those two power ratings are - from the get go - derived differently and A LOT of variation in how it's done exists.

Amp's output power should generally refer to average output power generated by a sinusoidal waveform (with very little total harmonic distortion) to x-ohm load throughout certain effective bandwidth. Unfortunately, often not all those conditions are exactly met when a manufacturer - or their marketing people - comes up with power ratings.

Basically they can...
- Measure something else than the average power. e.g. The peak power of sinusoidal wave is 2x the average one.
- Measure something else than the continuous power. e.g. Amplifiers can often produce momentary peak powers in excess to 2 x average one.
- Measure at limited range of frequencies. e.g. Amp performs to spec within 500 - 5kHz, but performance considerably degrades outside that specific bandwidth.
- Measure at different levels of THD. Use different "weighing" for the THD, simply visually inspect "peak clipping", etc.
- State output power at load impedances practically unsafe to the amplifier (e.g. 2 ohms).
...And pretty much all imaginable combinations. So in practice ratings may not be directly comparable at all. Even two commonly accepted standards to measure the average power exist that differ a bit in how continuously the amplifier is driven when rating is derived. So don't take those ratings as gospel.

Then we have the speaker power rating... really the thermal handling capability of it. This one is not traditionally derived using a sinusoidal input but using a noise source instead. The noise is filtered to have a specific crest factor, resemling input signals of some expected type (e.g. music). The speaker is driven with such a signal and the rating for power handling is derived from the point where the driver still can continuously operate reliably without excess overheating.

Again variation; what kind of noise, what kind of crest factor, how long is "continuous", etc. In addition we can naturally again derive average and peak power ratings. Firstly, the crest factor used in the standardized tests does not equal to that of a sinusoidal waveform. Thus we lose the chance to directly compare amp and driver power ratings. Secondly the comparison would have been moot from the start because of huge variation in how speaker power ratings are actually derived. If we alter crest factor we can change the power rating, if we alter the concept of continuous we can change the power rating, if we... You get it.

Then there's that huge oversight that speaker power handling rating only covers thermal effects - totally ignoring mechanic effects of excursion. Unfortunately, excursion is largely tied to reproduced frequency, so the cone must travel more at low frequencies when producing, say 1W, than at higher frequencies at same input power level. Effectively this means that we generally need much less input power than the rated thermal handling to cause overexcursion, which very possibly damages the driver. In practice the power rating simply ignores the other important failure mechanism of a loudspeaker.

Where does it lead us? The ratings can offer only slight guidance so ultimately you should trust your eyes, ears or other suitable instruments in determing how much power the speaker handles in practice from specific amps. Overexcursion is moderately "easy" to detect: If the speaker seems like it's about to die it probably is. Nastier is the case where you exceed the thermal handling cabability because you'll probably hear it when it's too late.

Good effort but some misdirection. It's good that you brought frequency into this epic little personal tutorial for the OP.

The box tuning determines LF excursions per watt input and resultant output.

 

[Bassamatic]

Can't help but think that a lot of these responses are way more complicated than what the OP wants to know. The essential information has been posted a couple of times but buried in detail.

The fundamental thing the OP needs to understand is that the head's rating is power output, the cab's rating is how much power it can handle. The cab doesn't produce any power on its own. He seemed confused about that.

A 200-watt head into a 1200-watt cab will give you 200 watts. The head puts it out and the cab can easily handle that. A 2000-watt head into a 1200-watt cab will blow it up - more power than it can take.

Understanding impedance and all the rest is important but that's the first, fundamental point.

THANK YOU! I was just about to say the same thing. The OP needs the basic info, not all kinds of extraneous stuff that is meaningless to him. AMP rating is power OUT - Cab rating is power HANDLING.

Please also consider that the amp's ratings are for CLEAN power, and amps can put out more for short peaks, so to be safe, cabs should be rated to handle more power than the amp can put out. The old margin was for speakers to be rated for double the amp's power output. The OP's 1200W cab will be able to take anything the 200W amp can put out, and if it is loud enough for him, he doesn't need to worry about anything else. Period.

 

[I Need a six...]

THANK YOU! I was just about to say the same thing. The OP needs the basic info, not all kinds of extraneous stuff that is meaningless to him. AMP rating is power OUT - Cab rating is power HANDLING.

Please also consider that the amp's ratings are for CLEAN power, and amps can put out more for short peaks, so to be safe, cabs should be rated to handle more power than the amp can put out. The old margin was for speakers to be rated for double the amp's power output. The OP's 1200W cab will be able to take anything the 200W amp can put out, and if it is loud enough for him, he doesn't need to worry about anything else. Period.

Well, I asked them to get into the details, that's why now that i understand the basics I want a more thorough explanation. I don't actually have a 1200 watt cab, that was just an example. I'm going to be getting a new amplifier set up at some point, and the thing I know is I'm a solid state guy, sorry tube fanatics i need a lot more info before I even THINK about looking into new gear