question about celestion g12m

[19sixtynine]

need some help for a simple question....

can a quad of the classic series g12m take all 100+ watts from my Lead....or will they melt?

i know materials and construction are a little different today, so wondering what the deal is.

thank you:)

[Scumback Speakers]

If you run your 100w over 4 on the volume/master volume...they will melt. Not sure when, but they will. Had too many clients do this then upgrade to the 65w voice coil versions who told me they did exactly what you are asking about.

How long? Anywhere from 30 minutes to 2 years in most cases. Depends on the volume setting, FX, guitar/pickups used, etc.

[19sixtynine]

hey, thanks jim. maybe a g12H would be better--

[Janglin_Jack]

If you run your 100w over 4 on the volume/master volume...they will melt. Not sure when, but they will. Had too many clients do this then upgrade to the 65w voice coil versions who told me they did exactly what you are asking about.

How long? Anywhere from 30 minutes to 2 years in most cases. Depends on the volume setting, FX, guitar/pickups used, etc.

Similar question, but what about a 50w head??

[Scumback Speakers]

The G12H30's would last a little longer, but not much. 100w heads can put out as much as 180-200w on JCM 800/900 models, up to 235w on some of the old high voltage Plexis.

A 50w cranked/dimed into four 25w G12M's should be good to go for a long time. At least I've been doing it to the same cab for about 7 years since I built my first Metro 50w clone and I haven't blown one...or one of my 20w M75-PVC's either, for that matter, for the last 16 months.

[julkke]

Are those power outputs measured? I've read 100w is more like 160-170 but over 200w? Wow.
Plate voltage does effect the output pretty much, doesn't it?

[demonufo]

Are those power outputs measured? I've read 100w is more like 160-170 but over 200w? Wow.
Plate voltage does effect the output pretty much, doesn't it?

They certainly have the potential to do it in peaks. The 100W amps from the late 60's/early 70's can often have 530V at the plates depending on your wall voltage. Whilst those Dagnall equipped amps will sag fairly hard when pushed (and the B+ will subsequently drop), the Drake's may not so much. And depending on how the amp is biased and the plate voltage, these amps can be real head-rippers (not to mention coil melters...)

[Scumback Speakers]

Are those power outputs measured? I've read 100w is more like 160-170 but over 200w? Wow.
Plate voltage does effect the output pretty much, doesn't it?

They certainly have the potential to do it in peaks. The 100W amps from the late 60's/early 70's can often have 530V at the plates depending on your wall voltage. Whilst those Dagnall equipped amps will sag fairly hard when pushed (and the B+ will subsequently drop), the Drake's may not so much. And depending on how the amp is biased and the plate voltage, these amps can be real head-rippers (not to mention coil melters...)

Wow, this is a hot topic on the TGP today, too. Ok...I explain it here for everyone:
http://www.thegearpage.net/board/showth ... st14343696" onclick="window.open(this.href);return false;

Or you can read the JCM800 manual for yourself here:
http://www.scumbackspeakers.com/specs/j ... rspecs.pdf" onclick="window.open(this.href);return false;

Or if you just want to see the power specs, I've made a jpeg out of that page you can click:
http://www.scumbackspeakers.com/specs/j ... rspecs.jpg" onclick="window.open(this.href);return false;

As for the 200w plus output, according to those more learned than I about power tubes, plate voltage and old Plexi circuits, my amp associates has measured on old 67/68 Plexi with plate voltage to the tubes IN EXCESS of 600 volts, I think he said it was around 675, and IIRC it was an old Super Bass. It was unmodified from what he could see.

That amp put out 235w when cranked up to 9.

Typically old Plexi 100w put out 180-200w, and they got tamed down a bit going into the 70/80's. But they still routinely put out 180w, and the JCM 800 manual page above shows 170w cranked, 115w clean.

I'm sure Marshall got tired of replacing speakers under warranty, and that's probably why the G12-65 and G12-80 showed up in the late 70's, so they could handle a 100w head cranked up through one cab.

But in the 60's and through the late 70's, all they had were 25w G12M's and 30w G12H30's. You wouldn't run a 100w cranked up to 7 long through those and expect it to last.

Hope that helps!

Jim

[julkke]

Thank you for all this great information!

[Scumback Speakers]

You are welcome, sir.

[jape88]

This has got to be one of the most posted questions on guitar forums worldwide and yet no one really comes forward and says no you shouldn't do it don't use a 100w amp at full volume through a cab with four 25watt speakers?

Celestion unless I'm mistaken don't print it on their boxes or say it on their website, although when questioned always say they're conservative ratings anyway? Marshall don't print it on their 100w AX cabs or say it on their website?
Just how confusing is this information to guitarists who don't frequent technical or info forums? imagine what confusion someone has setting up their brand new EVH 51503 100w amp with matching 4x12 cab with 20 watt speakers

Tbh, I think I've even seen posts and clips of dimed plexi builds through 100w cabs

[Scumback Speakers]

I've said "No you shouldn't do it!" for years. I've posted those JCM800 specs for years as well.

And frankly, no one follows up with those guys who dime a Super Lead into a 100w cab to see how long it lasted. But I have with some, they're the ones ordering 65w M75's to replace the blown ones.

I am relating to the Metro forum what I've been told by my clients and how they blew up their speakers. I've never fried a 4x12 intentionally, but then I've always used higher powered speakers.

I have taken a Rebel 20 amp, set the amp to 4 on the volume knob and played it through a 25w BlackBack for all of 8 seconds before it blew, though. Does that count?

I've also seen one of my clients use a G12-65 for 14 months with one of my 10w amps, then it blew. Go figure. That should have lasted forever.

There's a lot of misinformation and plain bad information on the internet from sources that really aren't qualified to post it. That's why you won't see me post about childbirth, brain surgery or menstrual cycle cramps, cuz I just don't have any experience with those subjects.

OK?

[rgorke]

.... or menstrual cycle cramps, cuz I just don't have any experience with those subjects.

OK?

But Jim, you are married, aren't you?

[Scumback Speakers]

.... or menstrual cycle cramps, cuz I just don't have any experience with those subjects.

OK?

But Jim, you are married, aren't you?

I'm also extremely lucky there...my wife has the shortest cycle of any woman I've ever met. If it's two days, it's an event. Typically it's 36 hours.

I know, I know...she's a total keeper.

[motorhead]

Long before the internet people were running 100watt heads into 100 watt cabs. i guess things just changed for no good reason? HHMMMMMMMMM