speaker break in with sine wave

[nekkio99]

hi folks

I have some new celestions g12m heritage and they need breaking in. I read posts explaining how to do so with a variac.

How about using a 60hz sine wave played though a power amp, measure the output voltage on the speaker terminals with a multimeter, and dose the volume until the voltage is the correct one to apply. Would that be the same - or equivalent - to using a variac?

many thanks!

[Structo]

Yeah, should be the same.
Just be careful not to overheat the voice coils.

According to Jim at Scumback Speakers, Celestions take a real long time to break in.

[bluesfendermanblues]

I use a 6.3 volt AC heater supply. Works like a charm.
If the speaker has high sensitivity I dampen the voltage a bit with a power soak aka l-pad

[TUBEDUDE]

That sounds good for stretching out the suspension and spider, but wouldn't a pink noise source be better to excercise the cone? So all of the cone surface can be flexed and not exercised in one mode only?
I've just played the hell out of the amp until i was tired, then ran the radio through it for half a day in a closet with blankets and quilts to attenuate the noise. (the head is outside the closet).

[nekkio99]

cool, thanks for you reply guys.

And yes Tom, I have read that celestions can take quite a bit to break in: I was thinking of going for 80 hours of 60hz sine wave, at 1/3 or the speaker capacity (7.3 volts for a 20 watts, 16 ohm speaker). Does that seem reasonable to you?

What do you think about pink noise vs 60hz sine wave? Any opinions?

[Scumback Speakers]

My two Heritages (H30 55hz, and G12M 20w (25w coil really) 75hz) took 9 days, 8 hours per day of the variac to get loosened up. In all honesty, I just got them to the point where my ears weren't being ripped off and stopped. In all likelihood, they probably need more.

I wouldn't sent the variac over 9 volts for these, two hours on, 1 hour off. Not sure if you'd cook the voice coils if you did it longer. I didn't, mine are 4-5 years old, though.

Be advised that after extensive personal testing (to destruction of many Weber built Scumbacks), the break in method Weber VST posted for years (and is copied to on other sites) is not safe, nor did Ted or TA Weber ever test it. I did.

I don't set any voltage higher than 9 volts any more. I just let the speakers run longer till the surround/spider are more flexible, then they are done. You can overdo it, which is why I'm recommending 2 hours on, 1 hour off to let the voice coils cool.

Hope that helps. Email me if you need more clarification.

[pdf64]

Is that 9V at 8 ohms (10 watts) or at 16 ohms (5 watts)?

[tubelectron]

Hi All,

Sorry, I didn't found the "welcome section" of this forum, so here's my 1st post - if there is a welcome section that I didn't saw, please direct me - Thanks !

If you are breaking-in speakers on 50 or 60Hz, the Z may be higher than the nominal 4, 8 or 16 ohms, due to Fs which is very close. At Fs the Z can reach 40-50 ohms, sometimes over, but fortunately it is very sharp, so the real Z at 50-60Hz should be circa 10-20 ohms...

On 50Hz, I use 6VAC rms, sometimes 12VAC on big speakers (15"), with a very simple, quickly-made and ruggered instrument I have built myself, designed to work continuously for days, thanks to its fan cooling. The pictures says it all :

[img:640:480]http://img15.hostingpics.net/pics/540257IMG8634.jpg[/img]
[img:640:480]http://img15.hostingpics.net/pics/708280IMG8635.jpg[/img]

I have another DIY instrument which can do that job, but it is more suitable for speaker condition test. it's a sine wave generator 0.5Hz to 30Hz, constant level, max power 10Wrms/8ohms. I added an external input to use pink noise, as suggested by TUBEDUDE, but I never took the time for a trial... Here's a pic showing the device, 2 speakers on breaking in, and a DMM to monitor the VAC on the speakers :

[img:480:640]http://img15.hostingpics.net/pics/469365IMG2995.jpg[/img]

Nonetheless, the 50/60Hz is correct for the all-around breaking-in, for sure...

A+!

[boots]

Wow, you guys have some great ideas! My quick & dirty way to get a speaker sounding decent (after the initial gently break-in) is to tune the guitar to drop D and get it started feeding back on the low D. Let it feed back for as long as your family can stand it. That seems to loosen things up pretty quickly, but probably is still no substitute for a full-scale break in procedure.

[Scumback Speakers]

Is that 9V at 8 ohms (10 watts) or at 16 ohms (5 watts)?

I just set it at 9v for both now. I do four at a time using parallel wiring. I set the variac at 9-10v, and then measure the voltage at the speaker terminal to make sure it's the same. Sometimes you have variac dials that are off, so you may have to adjust up or down to compensate.

Do not trust your dial on your variac, they can vary quite a bit. Something else I found out the hard way.

[David Root]

tube electron, welcome to TAG (The Amp Garage) and thank you for your post. You've obviously put some thought into this subject and put it into experience too. I think you are at the right place here!

[tubelectron]

tube electron, welcome to TAG (The Amp Garage) and thank you for your post. You've obviously put some thought into this subject and put it into experience too. I think you are at the right place here!

Thanks David !

A+!