Breaking in a speaker with 50/60 hertz

[guitarmike2107]

Does burning in speakers and caps with 50/60hertz ac voltages really help allot.

Ok here is my experience, A few months ago I bought a 15 ohm G12H heritage from JohnA on the forum, I didn’t plug it in at first, just stuck it straight into my burn in box with 6.3 volts/50 hertz signal. After about three days of buzzing I fitted it into a combo cab, the bass was huge but mushy and the highs weren’t great either.. I was initially actually very disappointed with a speaker that had great reviews.

Anyhow I have played it allot since, pumping it with proper guitar signal and it has really sweetened up, bass is no longer mushy and the high are lovely.

The whole experience has left me wondering whether breaking in a speaker with a frequency below its cone frequency is a good idea.
Maybe it has helped the speaker break in faster though….

Any thoughts

Mike

[kleuck]

I think this technique is just absolutely useless, not only because the frequency is well below the resonance peak of the speaker, but also because a low power signal doesn't have a chance to soften the cone nor the spider.

[zaphod_phil]

If the cone is moving, then the cone surround and spider are inevitably being worked, even if not at a very high amplitude. It's then just a matter of how long you leave it running for. And the surround and spider will gradually become more flexible. Ted Weber (RIP) also recommended gently rubbing some acetone on the surround doping, to help soften it, as well as applying some fabric softener to the cone itself.

If you wanted something that works faster, you could of course connect the speaker to an amplifier and run a sine wave from a signal generator into the amp' input at around the resonant frequency. You would get some huge cone excursions, but you would need to be careful not to damage your speaker at the same time.

Mike, I'm really puzzled by what you described. I've never encountered the problems you describe, such as the mushy bass, nor can I see any logical reason why that would happen. I would mainly expect highs to be shrill with a speaker that wasn't properly broken in. What you describe sounds like the surround and spider got too soft. But then could they have tightened up again? It sounds very strange to me.

[guitarmike2107]

Mike, I'm really puzzled by what you described. I've never encountered the problems you describe, such as the mushy bass, nor can I see any logical reason why that would happen. I would mainly expect highs to be shrill with a speaker that wasn't properly broken in. What you describe sounds like the surround and spider got too soft. But then could they have tightened up again? It sounds very strange to me.

Which I why I asked, maybe I ran it for too long?

All I know is at first start up I was disappointed and went straight to thinking about changing the circuit to reduce bass. But after a bit of really loud playing all seems fine and I am actually turning up the bass.

[kleuck]

If the cone is moving, then the cone surround and spider are inevitably being worked, even if not at a very high amplitude. It's then just a matter of how long you leave it running for. And the surround and spider will gradually become more flexible..

You can't replace amplitude by time Phil, it's not like comparing going home in a car or by feet, but more like trying to saw a tree with a butter knife : no matter the time, you won't be able to.

[guitarmike2107]

You can't replace amplitude by time Phil, it's not like comparing going home in a car or by feet, but more like trying to saw a tree with a butter knife : no matter the time, you won't be able to.

Its called fatigue loading, we are cycling the cone so that it moves N number of cycles at a certain power/stress, we can increase the power and decrease the amount of cycles or decrease the power and increase the number of cycles to get to the same place.... this is shown graphically on S/N curve diagrams.

If we were applying a really small voltage/low power so that the cone hardly moved then it probably would be a waste of time, which is what I think you are saying, but the cone definitely moves with 6.3v applied so its just a matter of time…. Even though some may still think it’s a waste of time.

From memory…the speaker power rating also drop significantly below the cone frequency, so pumping it with max power at these low frequencies would probably not be a good idea.

Now I wish I had plugged it in first to hear the difference, then I could swear by it….

[Camurai]

My break in procedure seems to work well for me. I use program material (plug my iPod into the amp's input and set it to random) and start at a low volume, gradually increasing it until I hit about 2/3 to 3/4 power. I wait until I have a day off from work so I can monitor it for about 8 hours or so. It's worked well for me so far, and I prefer the program material over a specific frequency as it simulates the full range of motion and material the speaker is likely to ever see.

[kleuck]

Hum.
It took me two weeks (a little more actually), playing almost full tilt and a couple hours a day to break-in a Jensen Alnico rated at 25 watts (15 watts amp).
How many weeks should I have needed to do the same with a mp3 ?

[Camurai]

Beats me. All I know is what's worked for me so far.

[kleuck]

Yes, but, i wonder (hope you understand what i mean, see my signature) is : what is this particular break-in method meant for ?
You will play trough your speakers i suppose, and there is no ball bearing or valve to break-in, so why don't just...play, and wait a few hours ?

[Camurai]

The theory is that new materials need to be gradually broken in before cranking them to maximize the lifespan of the assembly. It's the same idea as a break in procedure for a car, which typically requires 500 miles of gradual break in before driving it hard. This reduces the chance of breakage or abnormal wear on the moving parts, which can severely shorten the lifespan. The speaker has a motor assembly, and the surfaces wear against each other, so there are parts that technically should require a break in process.

[kleuck]

OK (i suspected that)
But i don't think this can apply to loudspeakers, where there's no really moving pieces, nor frictions.

[Camurai]

There is a good article on speaker break in here: http://www.audioholics.com/education/lo ... or-fiction

And here's a quote from the article that has some relevance:

When a newly-minted driver rolls off the assembly line it will typically not measure or otherwise perform as one of its well-broken in siblings does. In large part these differences arise owing to the fact that said driver's spider (often crafted of a varnish-impregnated linen) is not as compliant as it will become once it's broken in properly. Depending on number of mechanical factors relating to its design, construction and materials composition, a net post-burn in compliance increase on the order of 5% - 10% would not be unusual.

[paulschnettler]

OK (i suspected that)
But i don't think this can apply to loudspeakers, where there's no really moving pieces, nor frictions.

, I'd venture to say... the whole speaker is a moving piece!
That column of air that creates the sound pressure mass is moved by something!
Think about it... I agree about the frictions though.

[kleuck]

The amplitude of the movement is thin, really thin.

[zaphod_phil]

I think you've lost yourself in your own logic.

But i don't think this can apply to loudspeakers, where there's no really moving pieces, nor frictions.

True there's virtually no friction. But there are several moving parts - the voice-coil, the spider and the cone - as well as the air itself. That's why they're called moving coil loudspeakers.

[kleuck]

Yes
But, look at, for example, the datasheet of the Emi 1028 (alnico) : "Maximum Linear Excursion (Xmax) 2.1mm"

Thin.

[zaphod_phil]

Not as thin as your argument. If it weren't for the fact that loudspeakers are essentially moving devices (and contain a motor), we wouldn't even be worrying about the details of mechanically breaking them in.

But, look at, for example, the datasheet of the Emi 1028 (alnico) : "Maximum Linear Excursion (Xmax) 2.1mm"

Some speakers are designed for low cone excursion and some for high. The one you're quoting looks like a low excursion speaker. Guitar speakers are meant to operate with quite high excursions. In any case thick or thin or very relative terms.

[kleuck]

But, look at, for example, the datasheet of the Emi 1028 (alnico) : "Maximum Linear Excursion (Xmax) 2.1mm"

Some speakers are designed for low cone excursion and some for high. The one you're quoting looks like a low excursion speaker. Guitar speakers are meant to operate with quite high excursions. In any case thick or thin or very relative terms.

Really ?
It's the highest excursion i found in the Emi line of speakers (i did not check all of them though), most of them seem to sit between 0,5 and 1,3 mm, with 0,8 being the common value....even the 15"
Perhaps 0,8 mm is a huge movement for an ant, but for me, it looks like a small thing

[guitarmike2107]

Those figures may not sound like allot but this is a paper cone we are talking about not an elastic band, and its moving 2.1mm 50 or 60 times per second for several days. ~15 Million movements

I don’t know much about spiders… just I normally crush them because we have plenty