Powered Kemper and speakers

[Minning Around]

So, I'm pretty blown away by the Kemper abilities. They have a model that includes a solid state amp. It puts out 600 watts. What kind of speaker wattage would I need when running the amp cranked? The typical tube amp recommendation is speakers that will take twice the amp's maximum output. I sure as heck won't find a speaker that handles 1,200 watts. What gives? Is this different from tube amps?

[WRGKMC]

Its 600W at 8 ohms and 300W at 16 ohms. You surely wouldn't use a single speaker. You simply need to match the RMS values.

 

My 300W Marshall 1960 has 4 Celestion 75W cream back speaker which would run it. If I had two of the same cabs I could run a full stack at 8 ohms and it would take the full 600W.

 

If you want to be safe get a 16 ohm cab with 4X100w RMS speakers. That would give you an extra 100W headroom running the head at 16 ohms.

 

600W is insanely loud however and unless you are playing big arenas or outdoors concerts you'll never come close to ever need that kind of power.

[Minning Around]

Thanks. I think I understand.

 

I could run a 600-watt amp into just one speaker (any speaker, really) just so long as I keep the volume knob low enough to not distort the speaker. I have no idea how loud that would be but I'm assuming it would be loud enough for my use, which is at home and actually into a 2 x 12 Mesa cab. - should be plenty loud.

 

That brings up another question. Tube amps are known to sound "better" when cranked up a bit. With a solid state amp like the Kemper is tone as dependent on turning it up? Or do they tend to have a more consistent tone profile at various volumes than a tube amp would? The tone in a Kemper comes more from the programming than the amp itself. So the tone would be there no matter what the volume is set at, right? If that's correct, solid state amps would seem to be better suited for low volume use, at least if it is an amp that has great tone separate from the amplifier, like the Kemper does.

That disregards speaker affect. A speaker needs enough wattage to sound best too, right?

 

I think I'm just going to have to buy one and then play with my speaker options to find my sweet spot. I suppose the Kemper forum has all the answers. I'll check there.

[SteinbergerHack]

What amp did you have before the Kemper? My main amp is a Bogner XTC, but the Kemper has been whispering in my ear. Is it really as capable as it appears to be at first glance?

[DeepEnd]

. . . Tube amps are known to sound "better" when cranked up a bit. With a solid state amp like the Kemper is tone as dependent on turning it up? Or do they tend to have a more consistent tone profile at various volumes than a tube amp would? . . . That disregards speaker affect. A speaker needs enough wattage to sound best too' date=' right? . . .[/quote']

SS amps tend to sound about the same until they're overdriven. It would be possible to overdrive a 600 Watt amp but in most situations your ears would give up first. Depending on the speaker's characteristics and the Fletcher-Munson effect, it may well take a fair volume level to get the best out of a given speaker/amp.

[WRGKMC]

Thanks. I think I understand.

 

I could run a 600-watt amp into just one speaker (any speaker, really) just so long as I keep the volume knob low enough to not distort the speaker. .

 

I don't recommend that at all. Many ceramic speakers give you no warning before they blow and by the time you start hearing it distort it may be frying the voice coil. Been there and done it many times. You not only risk the speaker blowing but damage to the amp.

 

I have no idea how loud that would be but I'm assuming it would be loud enough for my use' date=' which is at home and actually into a 2 x 12 Mesa cab. - should be plenty loud..[/quote']

 

If the cab wattage is too low you could blow the speaker just powering the head up. Many SS heads have an initial power surge when you turn them on. Others use a series of relays to soft start them, tuning the preamp on before the power amp on. I haven't checked into it on that head however.

 

That brings up another question. Tube amps are known to sound "better" when cranked up a bit. With a solid state amp like the Kemper is tone as dependent on turning it up? Or do they tend to have a more consistent tone profile at various volumes than a tube amp would? The tone in a Kemper comes more from the programming than the amp itself. So the tone would be there no matter what the volume is set at, right? If that's correct, solid state amps would seem to be better suited for low volume use, at least if it is an amp that has great tone separate from the amplifier, like the Kemper does. That disregards speaker affect. A speaker needs enough wattage to sound best too, right?

I think I'm just going to have to buy one and then play with my speaker options to find my sweet spot. I suppose the Kemper forum has all the answers. I'll check there.

 

You should do your homework and learn more about amps before you buy anything. I have no idea why you'd want to get a 600W head to use in your bedroom when 15W is enough to drive your neighbors to call the cops on you. A 600W head is like 6 100W Marshall stacks containing 8 speakers in each stack. You only need that kind of wattage for huge arena events and even then most guitarists today use smaller amps and simply mic them. Smaller cranked amps give you manageable drive tones when playing loud. You need allot of distance between yourself and a high wattage amp. They are definitely not designed for home use.

 

Next the speakers and head have a symbiotic relationship when running together. The best match is when the speaker RMS wattage matches the head or exceeds it by 25%. You can go higher in speaker wattage but you loose something important whish is targeting its sweet spot.

 

Every amp (except for some that are designed to remain highly linear) has a sweet spot where tone and volume are ideal. Because of how tubes and transistors work, having a noise floor and ceiling, this sweet spot usually occurs between half and 3/4 max volume. Below 1/4 most sound claustrophobic. The tone controls don't work right and the sound is two dimensional. Above 3/4 the sound usually becomes unmanageable. Tube amps get too gainy and SS amps woofy.

 

Speakers too have a sweet spot which exists at the same ranges. They produce their highest fidelity with cone moving at with its maximum excursion. Higher and the cone maxes out its piston range and starts sounding nasty. Too little movement and your fidelity and dynamics just aren't right.

 

The best amps have the amp and head sweet spots match so you get ideal tone and dynamics when playing. You can only know this by experiencing it and having worked with an amp that has it. When you mis-match the head and that cab you shift that sweet spot and that occur at different power ranges. For example, an underpowered head may have its sweet spot for tone and dynamics at 50W, but your speakers have theirs at 100W. This may not matter if you get all your drive from pedals but my rule of thumb is, if you want great tone you begin with the amp.

 

The head and speaker should react to your playing skills when playing at your targeted volume level. For some that's 15W at rehersal, for others its 50~100W playing live. When you dig in hard on the strings its like stepping down on a gas pedal. If its a hot rod you should burn rubber for a few gears. Having a mis match is like an engine too small or too large for the body weight. You have over powered speakers for the head its like an engine too small for the car. You step don't on the gas and you fart away at slow speed. Its safe cause you wont hurt the speakers but you're killing your dynamic response. An over sized engine will obviously get up and go but it will rip the body to shreds, usually when you least expect it.

 

Best advice is, you have a mesa cab, get a mesa head to match and learn to use the thing. If you need more volume, you'd have to have a loud PA because the vocals always need to be louder then the instruments on stage. A 100W stage amp usually needs a couple of thousand watts of PA power to compete. I run a 3500W PA and I'm able to run some high powered stage amps. I can use small amps and simply mic them. I can pump sound through the monitors and give players as much stage sound as they need, but they CANNOT be louder then the vocalist or no one will be able to keep their place playing together because most players cue off the singer.

 

If I ever played a gig and someone hauled in 600W monster rig, I'd tell the guy to get lost. There no way I'm going to bust a gut and loose my voice trying to sing over that thing - and that's exactly what it amounts too. You can only get a mic on stage so loud before it begins to feed back. I need a really big stage and stick monster amps out on the wings so they aren't blowing me away so I can hear what I'm singing. I also want the other players to hear me singing and sound balanced in volume like they would on am album. A Bass player with an 300W SXT is the upper limit of stage volume. A guitarist a full 100W stack.

 

Anything louder is just unreasonable for any kind of club work and even then only 1/10 or the club owners will let you play that loud any more. this is why players use small amps now. They can get cranked tones at lower volumes and the audience can still communicate with each other. Not many places want loud bands. I've seen customers throw beer bottles at bar tenders trying to get a drink because the band was too loud for them to be heard.

[Minning Around]

I do have a Mesa head, a Lone Star. I'm just tired of dealing with tubes. I live in the country, techs are hard to find and it costs time and money. Plus, I've been through several amps and they don't match the absolute joy of my old Bedrock 50-watt head that eventually crapped out on me. Techs never could bring it back to it's glory days. So I'm going to try a solid state amp, the Kemper has all those sounds, it's light, should be reliable but who knows? I like the idea of only one amp instead of three or four taking up space.

 

Anyway, you're right, do the research first. Well, I did some. I'm not getting the powered Kemper. I'm getting the basic one without the amp and then maybe run it through a powered cab that is designed for this type of pre-amp. Currently, I'm leaning toward the Friedman ASM-12. Another option would be to run it through something like a Fryette Power Station, which is tube, if I want to stay with tube. Since I already have a suitable cab I may go that route.

 

BTW, living in the country, I can turn it up as loud as I want, go outside with my wireless and take a walk while playing. Keeps the dog happy.

 

Thanks for your advice. You are a wealth of information.

[Minning Around]

What amp did you have before the Kemper? My main amp is a Bogner XTC' date=' but the Kemper has been whispering in my ear. Is it really as capable as it appears to be at first glance?[/quote']I haven't actually tried one. You know how it is... It's a YouTube world. I'll go down and sample one though before purchasing. A lot of people are pretty blown away by them though. It would be useful for home recording. And it only weighs 11 pounds. The Friedman cab weighs around 50 lbs though. I think I'll leave that at home most of the time. I don't play out.

 

I do have one big concern about the Kemper. I haven't found this out yet but it looks to me like the gain, volume, etc., knobs may be a notched pan, as in, not infinitely adjustable, just notch to notch, you know what I mean? I HATE that type of pot. Hate it with a vengeance. It's something that could kill the deal. When I know for sure I'll post it up.

[SteinbergerHack]

I have no idea why you'd want to get a 600W head to use in your bedroom when 15W is enough to drive your neighbors to call the cops on you. A 600W head is like 6 100W Marshall stacks containing 8 speakers in each stack. You only need that kind of wattage for huge arena events and even then most guitarists today use smaller amps and simply mic them. Smaller cranked amps give you manageable drive tones when playing loud.

 

True for most amps, but not relevant to the Kemper. The amp-cabinet relationship is already in the signal before it ever gets to the power section.

 

With the Kemper, the idea is to use a very accurate power stage and full-range cabinet. Think of it as a source that you run direct into the soundboard, headphones/monitors, recording console, or into your stereo.

 

The Kemper profiles model the entire signal chain of your rig(s), so you can create a patch using a Bogner with a Marshall 4x12, a Super Reverb with internal speakers, and a Matchless. Since the profiling is done with the power section and cabinet in the chain, you don't want any additional "color" with the Kemper. It is more like a keyboard rig in this regard than like a traditional guitar amp.

 

Thus, the 600W SS power section is intentionally over-sized so that you will never run it anywhere near the point that it becomes non-linear. You would also not generally use a guitar cab with it, you would use a high-quality monitor cabinet.

[saturn1]

At least take a look at the Tech21 Power Engine - just a clean power amp that won't add any color to the signal from the Kemper. It has a 12" Celestion. It's only 60 Watts, but it's a loud 60 watts and you can daisy chain them if need be.

[WRGKMC]

I well understand what the units is. Its a modeling amp that models cabs too. 600W is still ridiculously loud. It may be its over rated however. Manufacturers commonly do that. It may and not produce nearly that much power. I own several PA amps rated for 2000/3000 watts a channel and they rate the wattage on a specific frequency pushing like 1000Hz till it distorts. Running full frequency thay may only get hald that power before distorting.

 

You'd still need speakers to handle the rating of the amp however.