How easy is it to blow a lower wattage speaker?

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maddnotez

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Have been considering getting a pair of Greenbacks but they are 25w (I am aware about the newer and other speakers with more watts)

So lets say I have a 2x12 and a 120w amp. Or hell even a 4x12 and a 120w amp.

Are these things gonna blow? I have heard you only get full wattage from an amp if you crank it beyond tolerable levels but idk if that is true.

For live practice at a decent volume is this a bad idea?
 
Not sure what your amp is, but look at this Marshall JCM800 amp manual I found online and posted on my site.

50w amps put out well over 90, 100w amps are 115w clean, and put out over 180w.

jcm800powerspecs.jpg


These amps make their rated power (clean signal, no distortion) around 3-5 on their volume knobs. Past that they get much louder and with more gain/distortion, which is where most of us like the way they sound.

Two 25w speakers for a 120w amp? You'd better keep that under 2-3 MAX, IMO.
 
-Jim's post is correct, and pretty much the golden rule for every amp manufacturer or BUT!! myself & the million's who ever had a -HALF STACK-(yup! 100 watt heads, 4x12 with greenbacks)-have literally never blown a greenback, and I'm a greenback guy! well, alright, I admit it, I'm a greenback hoarder!!.. And as we speak, right now, I have a 4x12 with two V-30's-(16 ohm each)-and ONE!!.. yes! JUST ONE!! 30w, 8ohm, 55hz, greenback!! been pounding the piss out of this detuned cab for over 3 years,

-greenback magic happens when there pushed-(the sound of a speaker with over extended cone travel, pushed over the limit is very noticeable, oh! and it sounds like shit too, the kids call it "flubby"
 
How are speakers rated? Are they not rated like amps, at wear they begin to distort?
 
messenger":1haechwe said:
How are speakers rated? Are they not rated like amps, at wear they begin to distort?
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Speaker ratings are all over the map, quite frankly, and the quality of what's used can change (not here, I've had a set formula for over a 1/2 dozen years since I took over production).

That falls under the "specifications subject to change without notice" disclaimer. I don't believe in that. You build a product to a spec, and you maintain the materials/workmanship to your spec.

That's not what happens elsewhere, though, sorry.

Rule of thumb for speaker survival, you have a 50w amp, you crank it to 6-7, hit an OD pedal, and you'll be near, or past 100w of power handling. I've had clients to do it with their 50w Marshall heads.

Now if you have an amp that's biased cold, dying power tubes, low testing preamp tubes, and weak pickups & pedals, you might be able to get away with running said 100w not up to spec head into a 4x12 100w (or 120w) cab.

But if Marshall figured a 100w head needed 8 25w speakers, and this was before exotic pedal gain boosts were available (usually a wah, flanger, echoplex, and maybe a fuzz like Jimi Hendrix), they knew why you needed 200w of speaker power handling.

I've had too many clients try the 100w head into a 100w cab thing for years. Right after they fry their favorite greenbacks, they ask me for a 65w recone. And Marshall usually sells 65 to 75w speakers in their single 4x12's now. There's a reason they did that, too.

Look, you can roll the dice, be my guest. I'm just telling you it's better to be safe than sorry, unless you have an unlimited output tranny and speaker budget, then do what you want!
 
Just an example for you. I bought a G12M blackback 7 years ago from a guy online. He sent it out to me, 25w 16 ohm, standard 1777 cone, T1221 model from 78.

I hooked it up to my Egnater Rebel 20, set the volume on 4. The speaker lasted 8 strums, literally, about 10 seconds.

So either I have the loudest badass Rebel 20, or a 25w speaker that tested good on my waveform generator just decided to take a dump after 10 seconds, although it shouldn't have.
 
I wouldn't push power ratings anymore since i don't bring backup cabs to gigs anymore. But i went years beating the crap out of a quad of Vox bulldogs (the original celestion alnico blues) i pulled out of an ancient vox cab i bought at a pawnshop. Sounded killer with the old cranked 200 watt mosfet Marshall power amp i used with it. Surprised i never fried the coils on those since they were only rated at 15 watts each but you get lucky sometimes. :lol: :LOL:
 
Built my buddy a 100 SLP with a PPIMV, he runs it into his Greenback loaded 4x12. He keeps the master volume about 75%, been gigging it every weekend for over a year no blown speakers so far.

There are many 4x12's now that run two GB' up top (ala Friedman style) this brings the cab wattage to 100w. People run 100w heads into these all day long, myself included.

As for a 2x12 GB cab, with a 100w head, that may be pushing it a bit. But YOLO!
 
Years ago (shit, almost 20 yrs) a buddy gave me one of his G12-65's that he pulled from his 100w JCM 800 2x12 combo. He told me he didn't know how long it would last since he pounded the absolute shit out of it for 2 years straight. I put it in a 1x12 cab and continued its punishment in my home studio. It lasted 2 weeks with my Demeter TGA-3. I caught its last 5-6 seconds of life on tape, and to this day, that is the best sounding 5-6 seconds of an E chord I've ever heard. Gave it back to the guy as a wall hanger. He still has it in his garage, hanging on a nail.

edit: sorry, my bad, I didn't digest the thread title: "...lower wattage..."
 
Scumback Speakers":27j44mrc said:
So either I have the loudest badass Rebel 20, or a 25w speaker that tested good on my waveform generator just decided to take a dump after 10 seconds, although it shouldn't have.
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:lol: :LOL: :lol: :LOL:

Nice.

Well thanks for all of the info from everyone. Sorry I did not mention I have a Uberschall Rev 2 with EL34 Quad, 120W. I play in a metal band but we are all about volume control and have really worked on our sound to be nice and even. While I will not b cranking the amp, it still is pretty loud IMO.

I have a 4x12 with V30 and a 2x12 with V12 Legends. I actually wanted to try a pair of Greenbacks in the 2x12 but now it looks like there is only one real solution.
 
I try to always use double the rating or more. I blew a EV-L years ago. So any speaker can be blown.
 
Just recently I destroyed my first speaker. I had a Celestion 70th Anniversary 30w in a 1x12 and messed it up with a 50w head I obviously turned up a little too much. I do recall it sounding fabulous pushed to its limits but unfortunately that lasted about 10 minutes. The gain and master were both less than halfway and that is all it took.
 
This conversation is about the Deliverance 120. A other 120 watt amp.


stratovarius said: ↑
"I was pushing it fairly hard:

More - On
Gain I - 3:00 o'clock
Gain II - 3:00 o'clock
Volume - 12:00 o'clock

With the bridge pickup selected on my Strat and the tone rolled back it just explodes with harmonics - hopefully not literally!"




"Yeah, literally. That's effectively fully cranked at that point. With the gains set that way, 9-10 o'clock on the MV is full power. Anything past that is just added compression.
The guy who said you should be able to do run the amp halfway all day long is right. And even though you are well past halfway, you should still be OK as long as you let it cool off from time to time. As always, using an attenuator allows you to indulge in full out power tripping without regard to sound pressure level. Under the circumstances, you'd be wise to bias the amp a bit on the cold side because with that much overdrive and the MV at noon, you're probably easily pushing 150-170W continuously. Figure that the power tubes are 50% efficient, so the demand on the power transformer is in excess of 300W. Meaning, the power transformer is going to get very hot."

David Phelge
Fryette Technical Support
 
^^^^^^^thanx for posting David, feel free to drop in anytime!... Door font have a lock, beer's in the fridge!!
 
Dave's not here. It's a quote. But am fairly passionate of beer.
 
stephen sawall":2o2cgppi said:
Dave's not here. It's a quote. But am fairly passionate of beer.
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-ha! I set ya up with a meat ball, right over the plate, to be knocked out of the park!!-(for the old Cheech & Chong bit)-
 
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