Speaker power ratings: a hard line?

Discussion in 'Amp Tech Center' started by Jupiter, Jan 23, 2020.

  1. Jupiter

    Jupiter Telefied Silver Supporter

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    I just ordered a 50-watt Quilter head. I'm planning to assemble a light cab with a neo speaker, but in the meantime, I have a cab with a G12H30 in it...

    I'm not planning to really crank it anyway, but I am still wondering what are the chances of blowing that speaker if I send more than 30 watts through it.

    I know that lots of stuff has spec limits set with a healthy fudge factor, but what about speakers? Is there a significant cushion baked into the specs or are they really gonna blow if they see more wattage than they are rated for?
     
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  2. Dacious

    Dacious Poster Extraordinaire

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    If you plug the 8ohm outlet into a 16 ohm speaker it should give you a modicum of safety.
     
  3. 1300 E Valencia

    1300 E Valencia Friend of Leo's

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    "I'm not planning to really crank it anyway".

    Guitar player's version of "Just the tip, I promise!".

    "I know that lots of stuff has spec limits set with a healthy fudge factor."

    Maybe... In the Russian Submarine Service.

    "Is there a significant cushion baked into the specs..."

    No. "Specs" comes from the same root word as "specific".
    In other words: "this is exactly what we mean and not something else."
     
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  4. stormsedge

    stormsedge Tele-Holic Gold Supporter

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    I have a 125w and a 300w (neo speakers) I use with my 201 Tone Block. No issues, but I am always conscious of the 125 limit when using the 125 single or paired with the 300...the 201 "volume" knob is marked in watts, so I keep it at 100 or below to allow for pedals, etc. That said, running it that way for a couple of bedroom sessions cured me...Quilters are powerful...I find it quite adequate at 1 or 2w through both speakers. Plenty of reserve to move to the deck and serenade the neighbors...bwahahahahaha:cool: (jk...I would never do that :twisted:).
     
  5. Jupiter

    Jupiter Telefied Silver Supporter

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    Yeah, I have a 15-watt Tweaker head I use with this cab and I don’t think I’ve ever turned that up even 2/3rds of the way, so I’m not too worried, but when I get the neo I’ll get one rated for at least 100w.

    I’m sorta interested in the possibilities of running two cabs; never done that before...
     
  6. Si G X

    Si G X Tele-Meister

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    I'd say the chances are pretty high.
     
  7. arlum

    arlum Tele-Meister Gold Supporter

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    As for as the fudging thing ....... a 30 watt cabinet will usually be able to handle an amp rated up to 36 to 38 watts. I don't believe I'd attempt a 50 watt amp through the same cab.
     
  8. elpico

    elpico Tele-Holic

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    Speaker power ratings are a very fuzzy "spec" indeed. So is the power output rating of amps for that matter.

    Music tends to have louder and quieter parts, notes and rests, then they try to guess what the average of all that is and say "the speaker can take music with an average power of x".

    Amps are usually rated by the strongest perfectly clean 1kHz tone they can produce but they can produce a LOT more power than their rated amount when driven into distortion.

    A common rule of thumb has been to use at least 2x the power rating of the amp when choosing the speakers. That's how we got the standard Marshall stacks. One cab had four 30w speakers and went under a 50w head. The 100w head was used with two cabs stacked up for 240w of speaker.
     
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  9. Jon Snell

    Jon Snell Tele-Meister

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    Loudspeakers have a power limit of course but the most important part is the sensitivity shown as the power received by a calibrated sound pressure meter one metre away from the loudspeaker. Shown as dB/Watt.
    A loudspeaker with a sensitivity of 101dB/metre Watt will be twice as loud as a similar speaker rated at 97dB/metre Watt because it is twice as sensitive.
    So the power rating becomes superficial.
    If you are using a Fender Blues Junior with a pair of EL84s in the amplifier, the rating of the speaker should exceed 30Watts as valve amplifiers have large peaks of power and can peak at more than the rated 18Watts. If the speaker is a Celestion Super 65, that will sound good and punchy but if it had an Eminence Black Mountain the sound output for the same power level will be almost three times that of the Celestion.
    I suppose it meets the saying that "one gets what one pays for".
     
  10. Lowerleftcoast

    Lowerleftcoast Tele-Meister

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    This.

    Can you get by with it? Sure, as long as you do not overpower it. Will you give it too much power? You might.

    My opinion. Some speakers have a power rating based on the voltage/amperes the coil can withstand.

    My opinion. Some speakers have a power rating based on when cone/mechanical breakup occurs.
     
  11. Si G X

    Si G X Tele-Meister

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    As far as I'm aware speaker maximum power ratings should be based on how much power a speaker can take before it starts to clip and distort, that's the baseline all are measured by so you can compare one to another.

    How far past that the cone will get damaged or the voice coil will collapse is what you can't know exactly.
     
  12. VintageSG

    VintageSG Friend of Leo's Ad Free Member

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    Do not use an octaver and square wave fuzz with it!.

    A clean signal poses less of a threat to the life of a speaker than a mess of square waves. Square waves, with their abrupt ramping, combined with fuzz, with its constant noise and harmonic structure, effectively ( and I have zero lab-tested, gluten-free, environmentally friendly tests to back this up ) derate your speakers by 50%

    Don't think that half volume = half power either. Thanks to science, it doesn't work that way. 30 Watts isn't much quieter than 60 Watts when the rest of the band is involved, but your drivers will notice.
     
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  13. draggindakota

    draggindakota Tele-Meister

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    It really depends on the speaker and the signal. A clean signal is more safe when overpowered than a distorted signal. In the world of car audio, especially bass competition, it's not uncommon for speakers to get fed sometimes double their rated power.
     
  14. schmee

    schmee Poster Extraordinaire Silver Supporter

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    I think you are fine. It's "SS watts..." regardless of wattage rating, most SS amps don't seem to produce volume like tube amps 1/4-1/3 their rating.
     
  15. Ricky D.

    Ricky D. Doctor of Teleocity

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    Risky.

    That volume knob is a gain control, not an output limiter. If your input is hot enough, you'll get whatever power the amp can generate.

    Voice coil heat is what blows the speaker. Distorted guitar signals are brutal.
     
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  16. telemnemonics

    telemnemonics Doctor of Teleocity Ad Free Member

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    My feeling is that speaker power handling is a more clear number than tube amp RMS output wattage.
    Since a tube amp rated power is "at clipping" and the Brutish, sorry British amps typically used with Celestions put out a whole lot more watts above clean AKA at clipping volume, a G12H30 in a 4x12 pushed by a 100w Marshall turned up past clipping would have seen more than 30 watts.
    But those G12M25 and G12H30 speakers would also blow in a 4x12 pushed by a 100w Marshall.

    Now you ask about a Quilter SS power section, promising to not turn it up past some nebulous volume level that has no actual number attached.
    I don't think any answer is correct because none of us can know one way or another.

    How do you equate "twice as loud" when turning up an amp?
    Bear in mind that turning an amp up to twice as loud means you turned up the wattage output to ten times as many watts.
     
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  17. jrblue

    jrblue Tele-Afflicted

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    It's hard to count on the watt ratings of anything as being accurate or absolute. Mesas, for ex., often go way, way louder than the wattage claimed. And I've had speakers blow in amps that have supposed outputs below the speaker rating, because some speakers can't really handle what they're rated for anyway. I would not be confident of a speaker handling power beyond its rating, and if we're talking about high-excursion bass notes or fast or sustained loud sounds, you can expect failure. Since I do not utilize speaker breakup in my sound, I rarely come close to exceeding my speaker's ratings.
     
  18. schmee

    schmee Poster Extraordinaire Silver Supporter

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    This is important for sure. You add OD and push hard and it's too much.
     
  19. Jupiter

    Jupiter Telefied Silver Supporter

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    Thanks guys, this is good input.

    The amp I got actually has the master knob marked in watts, but even that is kinda weird because the knob tops out at 50 watts, while some of the amps settings are said to go to 100w when full up, so, I dunno? Lol.

    I’ll stay well over on the easy side.
     
  20. Blue Bill

    Blue Bill Poster Extraordinaire

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    Risky. I blew a speaker once, running it past it's rating. It sounded glorious, just before it squeaked, and died. YMMV, though....
     
    Last edited: Jan 24, 2020
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