Here what I found on the celestion website:

How do I break in my speakers?

Important Note! Before breaking it in it's advisable to "warm up" the speaker gently for a few minutes with low-level playing or background hum.

Break in a speaker with a fat, clean tone: turn up the power amp volume to full, and control the level with the preamp gain. Use a level that will be quite loud, but not painful in a normal size room.

Have the bass and mid up full, and the treble at least half. On your guitar, use the middle pick up position (if your guitar has more than one pick up) and play for 10-15 minutes using lots of open chords, and chunky percussive playing. This will get the cone moving, and should excite all the cone modes and get everything to settle in nicely. The speaker will continue to mature over the years, but this will get it 95% of the way to tonal perfection in the shortest time.

What Do you think? who has any experience?

Dang Joe, to be honest I have never heard that befor about any speaker. I watch people install car sub's who are " in the know " and crank'em as soon as they have power. This is interesting. I wonder what a high end studio monitor mfg recomends. I would think that those are designed for "tonal perfection"

Well This is really new to me too, that why I would like to share this information

Ive never heard of this either thanks for the info

Your welcome, I've to admit that I'm a bit scared to put my power amp at full volume

do you mean to warm the speakers or the amp tube .warming amp tube thats important to get good quality
sound but to warm the speakers. !!!

No warm with hot sources indeed read better

This post has been edited by Joe Kataldo: May 23 2008, 09:51 AM

aha thanks Kataldo clear now

Surely there was something wrong, speaker cone are made of, well...paper

Audiophiles say you should do this with your home stereo speakers, or home surround system too. It takes a while before the speakers sound their best and you can speed it up and get better longlasting sound with this method. But I don't know if they are right or not.

And Celestion should know their business

You're right that audiophiles say it Blindwillie. I think it has something to do with the hystresis loop and memory effects - the cone doesn't move in a perfect line/circle but in a sort of 'S' shape that is more pronounced at certain frequencies etc - the idea is if you run the speakers in the memory imprinted into them won't be too extreme.

Whether or not any of this actually makes a difference well audiophiles also do other very nerdy things to get hifi but since this one is free there's no harm in trying I guess.

The manual for my Tannoy studio monitors make no mention of doing this though...

Cheers,
Tony

Well I actually heard about this , and there is something about it in my bass amps manual too..I heard it prologues life of speakers...But people are divided with opinion is it true or just a myth...
For me, I don't know - it sounds fair enough and its not a big hustle to do it when I get new amp/cab..

Exactly. They get into real weird rituals to get the perfect sound.
And my home speakers came with instructions to break them in. The Blackheart cab might have too, don't remember for sure. I followed the instructions for both.

I've done it this morning, and my speaker is safe at least

No direct experience here since I haven't owned a new cab yet but I have done some reading up on it on the guitar side and the audiophile side.

From what I can tell, it's not so much an issue of preserving the life of the speakers as it is working out the stiffness in the material when it's fresh out of the factory. They're supposed to warm up a bit with use and you can either play through that period or you can break them in and get it most of the way there ahead of time.

I've seen a few different ways to do this. There are demo/breakin CDs out there that the audiophile types will run through their speakers at decent volume (loud maybe but not full out). I've heard of guitar players run their CD player through the new cabinet and put an ACDC CD on and leave it while they're at work.

Oh yes I remember reading about it too (runing CDs through speakers)
Joe is safe now anyway

Why AC/DC, does My amp will sound like them after this break in

That would be cool

I think in general, speakers need to move a bit just to throw of the stiffness of their manufacture and kind of break in ... I have heard this about HiFI speakers and monitor speakers, so it probably true of all speakers. I would expect that just using them normally for a while will do the job, and they will slowly adjust and settle in. Maybe specific types of tones will help ... maybe not I think though, that just like you wouldn't take a brand new engine rallying, you wouldn't want to take a brand new set of Celestions to the limits of metal without a little bit of a windup first

This is probably corrent, though I wouldn't go full throttle first. Try 75%, 90% 100?