Speaker Burn In

JohnR · « **Reply #40 on:** 20 Sep 2005, 10:57 am »

I was perusing diyaudio and was reminded of this thread...

Here's a thread where someone actually measured the T/S parameters of some drivers before and after 65 hours "breakin." The parameters changed significantly more than the 5-10% claimed by the author of the audioholics article (who, as I think the first respondant pointed out, didn't actually measure anything...)

http://www.diyaudio.com/forums/showthread.php?postid=727398#post727398

The thread contains links to some other measurements which show significant changes even after 30 hours of breakin.

Dan Banquer · « **Reply #41 on:** 20 Sep 2005, 12:47 pm »

From what I understand more is coming from Audioholics on this. The thought occurs to me that if they are changing that much that is NOT a good sign. Does this say something about the quality of the drivers tested?
d.b.

Danny Richie · « **Reply #42 on:** 20 Sep 2005, 03:29 pm »

I have been measuring the Thiele/Small parameters on drivers for years. Burn in time or break in time certainly makes a difference. Weather or not the driver is hot or warmed up makes a difference too.

And yes, they can sound differently too.

ScottMayo · « **Reply #43 on:** 20 Sep 2005, 04:22 pm »

Quote from: Danny

I have been measuring the Thiele/Small parameters on drivers for years. Burn in time or break in time certainly makes a difference. Weather or not the driver is hot or warmed up makes a difference too.

Do you sell your speakers already burned in?

Dan Banquer · « **Reply #44 on:** 20 Sep 2005, 04:51 pm »

Danny: Do you have any before and after data? If so please share it with us.
d.b.

Steve · « **Reply #45 on:** 20 Sep 2005, 05:43 pm »

So when are you going to provide some proof of your own db? And we don't want your guess, or just one article from AH, as to whether breakin is necessary. Afterall, this is an opportune time to show us articles etc that can change our opinions.

Danny Richie · « **Reply #46 on:** 20 Sep 2005, 05:53 pm »

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Do you sell your speakers already burned in?

Since 90% of our direct sales are kits, then no.

Quote

Danny: Do you have any before and after data? If so please share it with us.

I don't have any saved data on hand, but if you guys can give me some time to get some pressing business priorities taken care of, I'll run some before and after measurements on various woofers and post the data for you.

After reading Steve's recent post, it looks like I need to go back and read this whole thread (I haven't yet). I take it this is one of those nay sayers verses yah sayer threads. Let me guess, has anybody claimed that its your ears burn in yet?

Dan Banquer · « **Reply #47 on:** 20 Sep 2005, 07:58 pm »

Thanks Danny, I'm looking forward to whatever you come up with.
d.b.

Danny Richie · « **Reply #48 on:** 20 Sep 2005, 11:26 pm »

Okay I have now read through the thread now and the original article about speaker break in.

From the original article there are some things that were observed that are very true. However there are assumptions made that are not at all true and a lot overlooked.

For one, the burn in process on a woofer is two fold. There are mechanical changes and electrical changes.

The mechanical are the easiest to grasp as they can be clearly measured.

Drivers don't burn in, in just a few seconds or minutes though.

A 1 watt signal for a few hours on a completed speaker isn't going to do it either especially if the speaker uses multiple woofers. When lots of woofers are used, like in a line source, they can play to high levels with little power and with little mechanical travel. If you don't move them much then the break in period (mechanically) takes a lot longer.

Still, when a woofer is burned in, the Fs drops. Qts drops. Vas goes up. It physically looses up and the compliance changes. I have measured in many times.

Electrically it changes as well. So do crossover components. Capacitors will go through more changes than anything else and it's all electrical. There is a lot that goes on and much of which is hard to measure. Yes it goes beyond simple inductance, capacitance, and resistance.

The fellows from Audioholics only looked at the mechanical changes.

Will the break in process change the frequency response? No not really. Very little measured response can be seen and the sonic changes that take place have nothing to do with frequency response.

However sonic changes during the break in process can clearly be heard and thousands of people ever year witness this. There are also those that never notice anything. It could be that they do not have the memory retention to do so or to discern apparent differences. It could be that their system simply is not of such quality to allow the differences to be apparent. I do not know and am not belittling those who have not witnessed such changes.

Those that have noticed changes in burn in often include non-audiophiles and inexperienced listeners too. Accounts here from bunky, Weez as well as Phil and myself shows quite a bit of diversity. You don't have to be a golden ear to hear these differences in burn in. Speakers do burn in, so do components, and cables. I don't have to understand it all to witness it either and if you haven't witnessed it yet then maybe one day you will.

ctviggen · « **Reply #49 on:** 20 Sep 2005, 11:59 pm »

Quote

Electrically it changes as well. So do crossover components. Capacitors will do through more change than anything else and it's all electrical. There is a lot that goes on and much of which is hard to measure. Yes it goes beyond simple inductance, capacitance, and resistance.

What else is there? Can't any capacitor or crossover be described using R, C, L?

Danny Richie · « **Reply #50 on:** 21 Sep 2005, 12:12 am »

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What else is there? Can't any capacitor or crossover be described using R, C, L?

Well, lets just look at variances in capacitors to start with.

Variances can include differences in dielectric constant, dielectric absorption, dissipation factor, dielectric thickness, film thickness, film material, types of termination, type of solder, connecting wire leads, charge and discharge rate, conductivity of the film, contact material, type of covering, etc.

Dan Banquer · « **Reply #51 on:** 21 Sep 2005, 02:12 am »

Danny: I have a question for you.
The long post that you did on page 5, is that the data that I asked about earlier or is my question premature?
Thanks;
d.b.

Steve · « **Reply #52 on:** 21 Sep 2005, 02:47 am »

Danny,

Couldn't have said it better myself.

Quote from: Danny

Quote
What else is there? Can't any capacitor or crossover be described using R, C, L?

Well, lets just look at variances in capacitors to start with.

Variances can include differences in dielectric constant, dielectric absorption, dissipation factor, dielectric thickness, film thickness, film material, types of termination, type of solder, connecting wire leads, charge and discharge rate, conductivity of the film, contact material, type of covering, etc.

Danny Richie · « **Reply #53 on:** 21 Sep 2005, 02:47 am »

Quote

The long post that you did on page 5, is that the data that I asked about earlier or is my question premature?

If you are asking about measured data, be patient and I'll get you some as time permits.

Danny Richie · « **Reply #54 on:** 11 Jul 2006, 04:16 pm »

As promised, some measured data.

http://www.gr-research.com/burnin.htm

I am sorry it has taken me this long to get to this. I just haven't had the time to get it done.

I actually started the process with a SW-12A, but then I installed it into the box and it just hasn't had enough play time and nearly zero hard play time on it and I could see that it was going to take a while to get it there. So I started over with a M-130.

Dan Banquer · « **Reply #55 on:** 11 Jul 2006, 04:25 pm »

Thanks; I will forward your link to Gene DellaSalla. Hopefully other speaker manufacturers will come up with data that correlates with yours.
d.b.

Danny Richie · « **Reply #56 on:** 11 Jul 2006, 07:03 pm »

For whatever it is worth, I have had custom drivers produced by seven different, large, well known manufacturers and their burn in data has correlated with my own.

One in particular won't even give me their measured data until the adhesives have had time to completely cure (2 days) and they put at least 20 hours of burn in time on them.

ZooDog · « **Reply #57 on:** 12 Jul 2006, 04:07 pm »

Interesting post, Danny. I wonder why no one has done this before? Would you say that some drivers need considerably more break-in than others? I know that Dynaudios in particular require a long break-in period (>300hrs).

Danny Richie · « **Reply #58 on:** 12 Jul 2006, 08:13 pm »

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I wonder why no one has done this before?

I am sure lots of people have. This stuff is common knowledge with driver manufacturers. You just haven't seen it posted for public view too often.

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Would you say that some drivers need considerably more break-in than others?

Yes, some drivers use materials that will relax more quickly than others. Some will burn in for longer periods of time electrically too. Many of the Dynaudio drivers (even the small ones) used large diameter voice coils. This could add to the time required as well.

Danny Richie · « **Reply #59 on:** 18 Jul 2006, 04:55 pm »

New data from 40 hours of burn in has now been posted, plus some responses from other industry professionals. Scroll to the bottom of the page.

http://www.gr-research.com/burnin.htm