Burning in Headphones ? WTF ?

[dannyf]

there will be a performance increase after run-in.

Why?

The fact that the speaker will perform differently after run-in doesn't, by itself, lend to the conclusion that it will perform better.

[Mark Hennessy]

there will be a performance increase after run-in.

Why?

The fact that the speaker will perform differently after run-in doesn't, by itself, lend to the conclusion that it will perform better.

Sigh

If the designer is half-way competent, the enclosure will be optimised for the stable, "burnt-in" drive unit. Hence, the box will be non-optimum for the brand new drive unit. I fail to see how I could have been any clearer about this.

It's really simple. Get some data about drive units (as new and "burnt in"), enter their parameters into a modelling program, and compare the optimum enclosures for each case. Then, transfer the new driver into the box that is optimised for the burnt-in drive unit and look at the differences for yourself.

[suicidaleggroll]

I thought Mark Hennessy explained it pretty well.

A speaker's enclosure and crossover network are designed and built for a specific combination of drivers.  The volume, shape, tuning frequency, crossover frequency, slope, etc. are all based entirely on the drivers' Thiele/Small parameters (T/S for short) and frequency response.  Speaker designers make sure that when they design the system, they use the T/S parameters for fully broken-in drivers, since that's how the speaker will spend the majority of its life.  This of course means that before the drivers are broken in, and the T/S parameters are out of spec, the enclosure, crossover network, and drivers are all mis-matched.  This can result in unnatural resonances and lulls in the response, a quicker-than-normal rolloff on the bottom end, some quirky behavior around the crossover frequency, etc.

Edit: too slow.

[tszaboo]

I agree that speakers/earphones may loosen up a little, though not as dramatic as people make out.

Though burning in DAC's etc is absolute nonsense!

Some two years ago, I've put together a small USB DAC with an output filter. I powered it up, put the sacrificial headphone on it, and it did not sound right. I was at the lab (workspace, lunch break), put a scope on it, and fired up the sinegen software. Ant there it was, strange clipping on the output on the positive side.
I went to the other room for a DMM when i returned, in front of my eyes the clipping disappeared, like something poped into it's place. It did not make this ever again. This wasnt 50 hour pink noise or whatever, just some 5 minutes, but it was there. Not everything audio related is bullshit.

[eV1Te]

If the designer is half-way competent, the enclosure will be optimised for the stable, "burnt-in" drive unit. Hence, the box will be non-optimum for the brand new drive unit. I fail to see how I could have been any clearer about this.

It's really simple. Get some data about drive units (as new and "burnt in"), enter their parameters into a modelling program, and compare the optimum enclosures for each case. Then, transfer the new driver into the box that is optimised for the burnt-in drive unit and look at the differences for yourself.

I would design the driver so that the material does not age to start with (this was maybe not possible 50 years ago when material selection was limited).

Sorry if I missed something written earlier in this thread, but I could not find any comparison of driver characteristics before and after they had been broken in, I did not find it in any datasheet from driver manufacturer when I checked a few.

Does anyone have data for any driver during the break-in period? I would be interested in knowing how big this effect is.

[dannyf]

If the designer is half-way competent, the enclosure will be optimised for the stable, "burnt-in" drive unit.

Why?

The volume, shape, tuning frequency, crossover frequency, slope, etc. are all based entirely on the drivers' Thiele/Small parameters (T/S for short) and frequency response. 

That's probably too simplistic of a view.

Speaker designers make sure that when they design the system, they use the T/S parameters for fully broken-in drivers, since that's how the speaker will spend the majority of its life.

I used to sit on the board of a fairly large pro-audio equipment manufacturer -  speakers, amplifiers and mixers + mics. I can tell you from personally experience that what you stated above cannot be further from typical design process in the industry.

You may want to think there is a lot of science in speaker design when in fact that's mostly an art.

[Mark Hennessy]

If the designer is half-way competent, the enclosure will be optimised for the stable, "burnt-in" drive unit.

Why?

Why not?

The volume, shape, tuning frequency, crossover frequency, slope, etc. are all based entirely on the drivers' Thiele/Small parameters (T/S for short) and frequency response. 

That's probably too simplistic of a view.

Why?

I used to sit on the board of a fairly large pro-audio equipment manufacturer -  speakers, amplifiers and mixers + mics. I can tell you from personally experience that what you stated above cannot be further from typical design process in the industry.

In which case, it appears that there is a world of difference between large-scale pro audio and the better small hi-fi manufacturers in the UK.

You may want to think there is a lot of science in speaker design when in fact that's mostly an art.

I strongly disagree. That might have been valid in the 1970s, and that might have been your experience more recently than that - unfortunately - but today good designers will use the science to get them most of the way there. Good designers will use simulation tools extensively, and know how to interpret the results. Good designers are constantly refining their models and their science. Good designers design their own drive units from the ground up. Good designers might even design their own blends of polymers to make their diaphragms, rather than relying on "stock" polypropylene. But despite all this, good designers recognise that you can't do it on measurements alone, and subjective testing will be the final arbiter. The final 10%, if you will.

In my experience, at least...

[suicidaleggroll]

Sorry if I missed something written earlier in this thread, but I could not find any comparison of driver characteristics before and after they had been broken in, I did not find it in any datasheet from driver manufacturer when I checked a few.

Does anyone have data for any driver during the break-in period? I would be interested in knowing how big this effect is.

From my post on the previous page:
http://www.klippel.de/uploads/media/Aging_of_loudspeaker_suspension_Klippel.pdf
http://www.gr-research.com/myths.htm

[coppice]

Some two years ago, I've put together a small USB DAC with an output filter. I powered it up, put the sacrificial headphone on it, and it did not sound right. I was at the lab (workspace, lunch break), put a scope on it, and fired up the sinegen software. Ant there it was, strange clipping on the output on the positive side.
I went to the other room for a DMM when i returned, in front of my eyes the clipping disappeared, like something poped into it's place. It did not make this ever again. This wasnt 50 hour pink noise or whatever, just some 5 minutes, but it was there. Not everything audio related is bullshit.

The 5 minutes of bias needed to properly form an electrolytic cap, maybe?

[SteveyG]

Better instrument separation

The track was mixed in the studio. you can try all you want , but you will not be able to alter that mix

    A more open sound stage

thae recording studio had a certain size. try all you might, you cannot change the stage that was used from your home. it would involve hauling your butt to the recording studio and the usage of heavy equipment like bulldozers to alter that stage ...

You've obviously never heard the difference in sound stage between open and closed back headphones.

Also, please link in some of the speaker manufacturers who specify a burn-in time on their products. I want to make sure I'm doing it right!

My B&W speakers stated the burn in period, and also to avoid using them at high volume levels during that period.

[n45048]

My new solid wood headphones arrived today! I'll be sure to burn them in ;-)

[IanB]

My new solid wood headphones arrived today! I'll be sure to burn them in ;-)

What's the deal with all those seams on the plastic parts? It makes them look really cheap 

[n45048]

My new solid wood headphones arrived today! I'll be sure to burn them in ;-)

What's the deal with all those seams on the plastic parts? It makes them look really cheap 

I assume you mean the stitching on the leather/pleather? How else would you design it?

[IanB]

I assume you mean the stitching on the leather/pleather? How else would you design it?

No, I mean the ridges in the plastic from the moulding process. They make the product look poorly finished.

[n45048]

I assume you mean the stitching on the leather/pleather? How else would you design it?

No, I mean the ridges in the plastic from the moulding process. They make the product look poorly finished.

Ahh. *shrug* It was a Kickstarter project, not bad for a first shot. They actually do sound rather nice and are very comfortable to wear.

[SteveyG]

I assume you mean the stitching on the leather/pleather? How else would you design it?

No, I mean the ridges in the plastic from the moulding process. They make the product look poorly finished.

Ahh. *shrug* It was a Kickstarter project, not bad for a first shot. They actually do sound rather nice and are very comfortable to wear.

600 ohm drivers I hope?