Everything you need to know about car audio

[AMI CUSTOMS]

SUBWOOFER BREAK IN

Why would speakers need breaking in? Are there any measurements or tests that have been done before and after performance that has shown a measurable difference?

Well, there are indeed several mechanism that are at work that cause the operating parameters of drivers to change through use. However, the notion that once one gets a speaker home it requires "breaking in" suffers from several problems.

First, as a driver comes off the line, its actual performance is fairly far from it's intended performance target. Reasons for this include the fact that the centering spider, typically manufactured from a varnish- impregnated linen, is far stiffer than needed. Working the driver back and forth loosens the spider considerably.

Now, one might say: there's objective proof of the need to "break in" a loudspeaker! Not so fast. The break-in period for the spider is on the order of several seconds, and if it takes you several seconds or minutes or whatever once you get the speakers home to loosen the centering spider, it's not proof of the need to break them in; it's proof that the speaker you just bought HAS NEVER BEEN TESTED!

But, on to other points.

When a driver is measured, there is a significant change in a variety of operating parameters as the speaker is driven. Usually, in a woofer, the resonant frequency drops as the speaker is used, often by as much as 10-20% (sometimes much more). This is due, as the question suggests, to a relaxing of the elastomers used in the suspension.

However, if one turns the stimulus off, within a few minutes, most, if not all, of the change has completely recovered, and we're back to go again. The elastomer has recovered from it's stresses (this is especially true of certain polybutadene-styrene surround formulations).

There are plenty of other real physical changes. For example, one can see a reduction of the electrical Q with time under heavy use, simply because of the positive temperature coefficient of the resistance of the voice coil. Allow the speaker to cool down, and it's completely recoverable.

Get it hot enough, and you might permanently lose some flux density in the magnet. But you have to get REAL hot to do that. Hotter than most of the compounds used in making a speaker can endure without catastrophic failure (damned few glues, varnishes, cones and insulating materials can withstand the temperatures needed to reach the Curie points of the typical magnetic materials found in loudspeakers).

What about the adaptive signal processing abilities of the brain? Could it be not the speakers which get broken in, rather one's ears?

When this has been suggested, despite the fact there's about a century of research backing it, it is more often than not greeted with jeers and sneers. See, you can't sell special "break-in" CD's if the speakers aren't broken in.

Why do people have so many opinions on this then?

Well, there will be loads of opinions. However, actual data on several thousand drivers don't seem to give two shits about opinions, the usual claims of "mysterious unmeasurable quantities" notwithstanding.

So what's the final verdict on subwoofer break-in?

It's a myth created by those who don't fully understand how a driver works. The only time you'd really have to worry is when the ambient environmental temperature is so cold that the drivers performance is affected. And even then, the dispersion of heat through the suspension is rapid. The ectothermia the driver goes through is enough to overcome the extreme cold temperatures rather quickly. But on a side note, drivers (and amplifiers) have been known to perform better down to 0°C (32°F) under the right circumstances.

Okay then, so if I buy an AQ HDC3 15 that has a 6 layer spider and the company who makes the woofer recommends 10-12 hour break in period to loosen the spider up, I can just ignore that since it is a myth about breaking it in and I can put that sub in my wall and drop 2kw+ of power on a burp and it will survive??? Interesting....

[Noob_On_Droid]

Okay then, so if I buy an AQ HDC3 15 that has a 6 layer spider and the company who makes the woofer recommends 10-12 hour break in period to loosen the spider up, I can just ignore that since it is a myth about breaking it in and I can put that sub in my wall and drop 2kw+ of power on a burp and it will survive??? Interesting....

This sounds silly, it is MORE likely to survive when its new and stiff as opposed to soft. The difference, is that it will be probably louder and definitely lower after its softened up. This is AQs way of saying, "don't judge the speaker until it has loosened up and reached its potential"

[AMI CUSTOMS]

This sounds silly, it is MORE likely to survive when its new and stiff as opposed to soft. The difference, is that it will be probably louder and definitely lower after its softened up. This is AQs way of saying, "don't judge the speaker until it has loosened up and reached its potential"

It is also more likely to rip the spider when it is stiff, no?

[tlee2]

good post man

[MDWSTBoom]

Excellent post NEO I've been into mobile audio for 20 years plus and you hit on things I wasn't even sure about this is a must read for all noobs.

[Neo_frog]

Okay then, so if I buy an AQ HDC3 15 that has a 6 layer spider and the company who makes the woofer recommends 10-12 hour break in period to loosen the spider up, I can just ignore that since it is a myth about breaking it in and I can put that sub in my wall and drop 2kw+ of power on a burp and it will survive??? Interesting....

As a matter of fact, yes. You could probably burp 5000W and be safe assuming you're burping correctly.

You're confusing playing music with burping. The average customer generally buys audio equipment based on "volume" of music. The audiophile knows to look for T/S parameters and test specific operating conditions conducive to their desired listening environment. Is IS possible to have a cleaner response curve if the music is played low for break-in to allow equal distribution of stresses across the suspension, but if you're tuned correctly, playing a clean signal, and are using the appropriate enclosure to match driver compliance requirements (again, based on testing) then break-in is unnecessary since you'll be achieving the same goal. Average Joe doesn't know this, so companies give them the means to loosen the suspension with a time window of easy play.

[Neo_frog]

It is also more likely to rip the spider when it is stiff, no?

If you are sending a non-sinusoidal signal, then yes.

[AMI CUSTOMS]

If you are sending a non-sinusoidal signal, then yes.

If you have enough power behind the signal, it won't matter if it is square or sine wave, the sine wave will rip a stiff spider loose from the basket if not loosened up. I have personally done it on several woofers. Yes the average run of the mill sub doesn't need break in, but a multi layer spider setup will need to be loosened up before taking the driver to isn't full potential. If you don't do this then be prepared to be removing the woofer from the enclosure and putting some epoxy around where the spider attaches to the basket.

[SHOWAGON]

Can anyone help me !?!

i just bought a whole new rockford system , (2 - T1D212's) & (1500-1bdCP)

This might sounds really stupid , but i'm trying to keep it as "stock-looking" as possible .. so i didnt buy a head-unit..

I drive a 1996 ford tauras sho(wagon) is there any possible way of hooking the subs and amp into my stock headunit ..

I've heard of running your RCA's to the rear speakers , but obviously there has to be SOMETHING that runs to the head-unit ?

can someone please explain to me how to do that , if its even possible ! THANKS FELLA'S

[Torres]

If you have enough power behind the signal, it won't matter if it is square or sine wave, the sine wave will rip a stiff spider loose from the basket if not loosened up. I have personally done it on several woofers. Yes the average run of the mill sub doesn't need break in, but a multi layer spider setup will need to be loosened up before taking the driver to isn't full potential. If you don't do this then be prepared to be removing the woofer from the enclosure and putting some epoxy around where the spider attaches to the basket.

what about the people who recone woofers during comps just to mount them and burp them with an ass ton of power? or do they just beef up the said weak points to prevent such things from happening? such as the spider joints to the basket? just curious