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Behringer watts ????

Started by liquidsmoke, October 24, 2011, 12:37:59 PM

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liquidsmoke

Is there ANY way to find out what Behringer amps are rated at for watts RMS at 8 ohms and 4 ohms? These jokers seem to only state peak wattage and I'm guessing they list the 2 ohm ratings. Their prices seem low but that is probably because they more or less lie about the power of their amps.  >:(

dunwichamps

Peak voltage can be approximated as VRMS * root(2)

of course this is frequency specific, they are most likely quoting power at say 1khz.

liquidsmoke

Quote from: dunwichamps on October 24, 2011, 12:39:56 PM
Peak voltage can be approximated as VRMS * root(2)

of course this is frequency specific, they are most likely quoting power at say 1khz.


Can you help me with the math on "VRMS * root(2)"? Is that an equation for figuring out RMS from peak?

dunwichamps

yes, divide the peak power by root 2 and there you get an idea of the RMS power.

liquidsmoke

Quote from: dunwichamps on October 24, 2011, 01:01:39 PM
yes, divide the peak power by root 2 and there you get an idea of the RMS power.

Cool, I'm just not sure what "root 2" means.

dunwichamps

Quote from: liquidsmoke on October 24, 2011, 01:07:38 PM
Quote from: dunwichamps on October 24, 2011, 01:01:39 PM
yes, divide the peak power by root 2 and there you get an idea of the RMS power.

Cool, I'm just not sure what "root 2" means.

square root of 2

approx 1.414

Hemisaurus

They're new powered mixers I think may be peak watts, the old EP power amps are RMS, which model are you looking at?

I like Behringer, you can download the manuals ahead of time, and know what you're getting, so I don't have your experience.

liquidsmoke

Quote from: dunwichamps on October 24, 2011, 01:10:16 PM
Quote from: liquidsmoke on October 24, 2011, 01:07:38 PM
Quote from: dunwichamps on October 24, 2011, 01:01:39 PM
yes, divide the peak power by root 2 and there you get an idea of the RMS power.

Cool, I'm just not sure what "root 2" means.

square root of 2

approx 1.414


Ah, cool, thanks.

liquidsmoke

Quote from: Hemisaurus on October 24, 2011, 02:24:27 PM
They're new powered mixers I think may be peak watts, the old EP power amps are RMS, which model are you looking at?

I like Behringer, you can download the manuals ahead of time, and know what you're getting, so I don't have your experience.

Mainly looking at their bass amps. No ohms listed on their website and all seem to be listed at peak. Very lame. I shouldn't have to download the manual on each amp to figure out the exact watts for 8/4/2 ohms RMS and even then I'd be surprised if RMS was even listed. Who cares about peak watts?

dunwichamps

Quote from: liquidsmoke on October 24, 2011, 02:37:01 PM
Quote from: Hemisaurus on October 24, 2011, 02:24:27 PM
They're new powered mixers I think may be peak watts, the old EP power amps are RMS, which model are you looking at?

I like Behringer, you can download the manuals ahead of time, and know what you're getting, so I don't have your experience.

Mainly looking at their bass amps. No ohms listed on their website and all seem to be listed at peak. Very lame. I shouldn't have to download the manual on each amp to figure out the exact watts for 8/4/2 ohms RMS and even then I'd be surprised if RMS was even listed. Who cares about peak watts?

Not me but you can get the RMS, it again depends on how sensitive your speakers r 2

Hemisaurus

Hmm, yep a lot of peak watt readings, some non-descript ones. It's not that hard to figure out.

Seems there's a whole lot of wiki related to it http://en.wikipedia.org/wiki/Audio_power

RMS is a pretty meaningless reading in speaker terms, unless you're a noise or drone artist, if you don't foresee yourself running a continuous sine wave into your speakers, pay more attention to the program rating of your speakers. There's different opinions on how to judge it, check the Yamaha bible, here's what the wiki says

QuoteCharles "Chuck" McGregor, while serving as senior technologist for Eastern Acoustic Works, wrote a guideline for professional audio purchasers wishing to select properly-sized amplifiers for their loudspeakers. Chuck McGregor recommended a rule of thumb in which the amplifier's maximum power output rating was twice the loudspeaker's continuous (so-called "RMS") rating, give or take 20%. In his example, a loudspeaker with a continuous power rating of 250 watts would be well-matched by an amplifier with a maximum power output within the range of 400 to 625 watts

I tend to look at the speaker, and the size of the voice coil, as well as reading the specs, and I'd do the 20% below, rating, so I wouldn't push more than 400W or so into a 250W speaker. Unless I'm doing drone, and then I match or undermatch ;D

Oh and if you put speakers in a horn, everything changes, I pushed 1500W into a pair of 300W speakers in my bass bins, and they took it and came back for more ;D

SpaceTrucker

I've Never overpowered a speaker before, I also have never blown a speaker before... Go figure. And by not overpowering, I mean not putting more than the rms of the speaker into it. Anymore and bye bye voice coil if you feedback or hold a low note too long. Hell, I feel weird putting the rms in a speaker. I'm sure you can run a speaker and pump more power in it, but your only gonna tear it up.

Hemisaurus

Yep that's the simplest way it to err way on the side of caution, and barring accident your speakers may live a long and happy life.

Of course you're going to also be rather quiet, but you can just add more watts, and more speakers ;D

My bass rig is somewhat more of a PA than a bass rig.

Lumpy

Not too hard to look it up in the User's Manual (usually one of the last pages has the specs). Their business tactics are a little sketchy, this is more of the same.
Rock & Roll is background music for teenagers to fuck to.

liquidsmoke

I appreciate all of the info but this is getting to be too much. This shit is nuts. I have access to two 15" cabs to use which I believe can each handle 500 watts RMS. I will get as much amp as I can afford but it won't be anywhere near 2,000 watts, holy fuck! I'm going for solid state and can't afford near that much power and just think of how many TUBE Ampeg SVTs(if one had to have tube amps) you'd need to generate that kind of power! "Yeah I spent $14,000 so I could put out double the RMS load that my cabs can handle, neat huh?" Uhhh...
Yes of course I realize you can't hook like 6 or 7 amps up to 2 cabs... and now someone will tell me it's possible.
;D

I need a beer.

2 8 ohm cabs = 4 ohms. Well, maybe I can afford 200 or 300 watts total at 4 ohms, we'll see. If it's loud enough it's good enough and it will have to do even if it isn't nearly as loud as it could be. Now I guess I know why some 15" bass cabs can "only" handle 150 watts.

My Fender 15" combo is only rated at 100 watts RMS, hell maybe I should just try to get another one for cheap, would be the same as 2 15s with a 200 watt amp.

Lumpy

If you're looking for a power amp (not a head) you should be able to easily get enough watts to drive your two cabs @ 4 ohms for cheap, or run each 8 ohm cab on it's own channel. You can probably go with a mid-level power amp and still have loads of headroom. I would buy something used, rather than a new Behringer. Behringer makes some good shit and I'm not a hater. But I tend to buy their stuff when it's a money-saver. In this case you can probably buy a better used power amp for the same money or less, from Crown, Crest, Peavey or QSC.

Example: Crown XTI2000 cab, 475 watts per side (stereo mode) @ 8 ohms. 350 dollars.
Rock & Roll is background music for teenagers to fuck to.

Lumpy

Rock & Roll is background music for teenagers to fuck to.

liquidsmoke

I would prefer a regular head with preamp built in, more knobs to turn and adjust for the perfect tone. I tried my Sansamp slaved into a guitar head over the weekend(the amp part should be the same, no?) and something sounded missing although right now this is for guitar, the "bass" side of my split rig(tuned down to G).

I like some of those power amp prices though.

Lumpy

#18
Ok sorry, I was confused.
Rock & Roll is background music for teenagers to fuck to.

liquidsmoke

Quote from: Lumpy on October 25, 2011, 02:35:55 AM
Ok sorry, I was confused.


No it's cool and thanks for the link with the power amp prices.

jibberish

I would like to add my home audio 2 cents worth to this.

a lot of this discussion would have been VERY pertinent to home audio.

there was needed a common power rating system.

1) an amp can burst the most power right in it's sweet spot frequency. usually 1khz was used in an audio freq amp(10 octaves 20-20k).
SO, any amp can put out more power at 1khz than across the entire 20-20khz range

2) an amp can burst more power as long as its power supply/cap reserves etc had something left. a serious power supply could go longer, but a cheap one can still max out the circuit for a short time.

peak ratings were no good in this context. so RMS was used..like someone said "drone" yes, can it push that amount of power for the long haul?

3) amps generally have less distortion mid operation range, 1khz was still pretty good for this too. also there are several types of distortion. a sine wave has less potential for distortion than a piano concerto as there is a single simple wave being played.. no IM between frequencies and more.

so the bandwidth was specified 20-20k to stop those cheaters

4) lastly, in home audio, the easiest way to kill a tweeter is running an underpowered rig into clipping. transistors clip ugly and basically put the power rail as it's output. alonmg with very energetic ugly harmonics

so at home you would want to exceed the speakers power rating with the amp rating. a 200w rms lets say peak 500w, like my cerwin vegas etc speaker can take a 1000watt transient and not melt, from a w/e 500w/ch amp, yet asking like a 50w/ch receiver with shit components to do that same thing would waste the tweeters because the receiver amp would puke when asked to reproduce that. Obviously you have to pay attention to the speaker since you could overdrive it cleanly but melt it. so you have to listen for the drivers hitting max travel(bass gets nasty, out of control)

5) in home audio, putting too low impedance of a load will flow too much current and melt your output transistors.
you could put a 100ohm speaker on your receiver and it wont hurt that amp a bit. it just wont get loud due to the impedance mismatch and really limited current flow.
Now, what happens if you put 100ohm speaker on a 4 ohm tube amp output????

In conclusion, ive been seeing a lot of differences in tube music amps as i learn about them as compared to the SS home audio which i know very well. and a lot of the lingo is in limbo between the two = much potential for major confusion

Hemisaurus

http://www.scribd.com/doc/55290985/Yamaha-Sound-Reinforcement-Handbook-2edition

Type 217 into the little box in the bar at the bottom to see the 217th page, or read all 431 if you have the time ;D

liquidsmoke

Quote from: jibberish on October 25, 2011, 03:58:33 AM
In conclusion, ive been seeing a lot of differences in tube music amps as i learn about them as compared to the SS home audio which i know very well. and a lot of the lingo is in limbo between the two = much potential for major confusion


I used to work with a guy, an audio buff of sorts(well he had a $20,000 stereo system in his basement) who claimed there was no difference in volume between solid state and tube watts after I said that tube amps are louder than solid state amps. I said that because guitar players tend to believe that and so I believed it.

moose23

My understanding re tube and SS watts is that tube amps are rated at a max before any distortion happens and we generally like tube amps when they're distorting so we get a lot more power then they're rated for. SS amps are also rated before distortion but SS distortion is generally not so appealing.

Hemisaurus

Quote from: moose23 on October 25, 2011, 01:17:09 PM
My understanding re tube and SS watts is that tube amps are rated at a max before any distortion happens and we generally like tube amps when they're distorting so we get a lot more power then they're rated for. SS amps are also rated before distortion but SS distortion is generally not so appealing.

He got it, also a tube amp compresses when really pushed, so it raises the perceived loudness of the amp. A SS amp just clips, and makes things sound ugly.