IPB

Welcome Guest ( Log In | Register )

3 Pages V  < 1 2 3 >  
Reply to this topicStart new topic
Help with headphone break in
Nessuno
post Apr 18 2013, 22:20
Post #26





Group: Members
Posts: 423
Joined: 16-December 10
From: Palermo
Member No.: 86562



QUOTE (antz @ Apr 18 2013, 21:51) *
No, what he's referring to is standard practice for equipment that must not fail (e.g. military). All components and the resulting assembly suffer from what's called infant-mortality, whereby new equipment can suffer early failure. Once past a certain threshhold, equipment that didn't fail is likely to be highly reliable for a long (and usually predictable) time. Critical equipment will be taken out of service before it's time-expired. This doesn't only apply to electronic gear, things like jet-engines are treated similarly.

Those practices, and strict quality control in general, are required in fields like military, medical, avionics, automotive and the like, where failing devices could cause catastrophic results like death, injuries or economic loss or in fields like scientific or research labs where the customer is very competent and could sue the seller if the device acts out of specifications. And they do have a cost! DVDdoug, how much of the production cost (not selling price) of the device your company produce is due to QC (burn-in, factory calibration etc...)?

With audio gears we are in a completely different field: none will be actually harmed by a deviation of some percent of distortion, plus audiophiles often are technically very incompetent people who believe in magic and kitchen table tweaks to improve engineering choices and companies try to minimize production costs, no matter how disproportionately high they will charge their customers: that's business! A certain rate of warranty repairs or even rejects are far cheaper than a systematic aging procedure and higher rate production scraps.

That said, personally I've never experienced performance variations that can be consistently related to any burn-in effect and don't believe this could happen in just properly designed electronics, not after a few hundred working hours and not as an improvement, for sure. I only keep an open mind for transducers where mechanics is involved (and for the reasons above).


--------------------
... I live by long distance.
Go to the top of the page
+Quote Post
MikeFord
post Apr 19 2013, 00:58
Post #27





Group: Members
Posts: 132
Joined: 22-May 04
Member No.: 14241



Don't we have some type of acoustic memory, a frame of reference to what things are "supposed" to sound like, that may take some time to accommodate a change in that frame of reference?
Go to the top of the page
+Quote Post
Propheticus
post Apr 19 2013, 01:07
Post #28





Group: Members
Posts: 219
Joined: 10-September 11
Member No.: 93615



QUOTE (DVDdoug @ Apr 18 2013, 20:33) *
IMO burn-in/break-in is total nonsense! And if it's true (or to the extent it's true), it's a very bad thing!
3. If the specs/performance change after burn-in (or several hours use) by the end user, the manufacturer's factory tests & specs mean nothing... It's a poorly designed & built product by an incompetent manufacturer! If the performance/specs are not stable, the manufacturer has no idea if the customer is getting a great product or a crappy product. There's always going to be some performance drift, aging, and some measurement variation. But the drift should be insignificant, and most importantly the product shouldn't drift out of spec (at least for a year or more).


Can't it be the manufacturer is aware of changing specs due to ware and tare/burn-in and compensate for this? As conducers are not purely electronical but also mechanical (moving/vibrating parts), I expect they can ware. Bend something often enough and it's integrity will degrade (hair fractures). Compensating will likely have to be a compromise and aimed at an average if the performance keeps changing throughout the product's life. I wonder if this break-in or ware is linear or has a steep curve in the start and then levels out...

This post has been edited by Propheticus: Apr 19 2013, 01:10
Go to the top of the page
+Quote Post
greynol
post Apr 19 2013, 01:37
Post #29





Group: Super Moderator
Posts: 10085
Joined: 1-April 04
From: San Francisco
Member No.: 13167



QUOTE (MikeFord @ Apr 18 2013, 16:58) *
Don't we have some type of acoustic memory, a frame of reference to what things are "supposed" to sound like, that may take some time to accommodate a change in that frame of reference?

Yes and it lasts on the order of a few seconds. Anything beyond that point is prone to being influenced by factors that may not even be related to the actual experience of interest.

This should not be news to anyone who has followed one of the many similar open discussions that exist on the forum.


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
DonP
post Apr 19 2013, 01:41
Post #30





Group: Members (Donating)
Posts: 1471
Joined: 11-February 03
From: Vermont
Member No.: 4955



QUOTE (Nessuno @ Apr 18 2013, 16:20) *
DVDdoug, how much of the production cost (not selling price) of the device your company produce is due to QC (burn-in, factory calibration etc...)?


The last time I was doing "shake & bake" testing it took a 25 cent part up to about 2 dollars. This was with hundreds of parts in a rack.

Go to the top of the page
+Quote Post
greynol
post Apr 19 2013, 01:43
Post #31





Group: Super Moderator
Posts: 10085
Joined: 1-April 04
From: San Francisco
Member No.: 13167



QUOTE (Propheticus @ Apr 18 2013, 17:07) *
Can't it be the manufacturer is aware of changing specs due to ware and tare/burn-in and compensate for this? As conducers are not purely electronical but also mechanical (moving/vibrating parts), I expect they can ware. Bend something often enough and it's integrity will degrade (hair fractures). Compensating will likely have to be a compromise and aimed at an average if the performance keeps changing throughout the product's life. I wonder if this break-in or ware is linear or has a steep curve in the start and then levels out...

I won't hold my breath for this to get beyond the realm of conjecture. If I did I'd be long dead.


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
DVDdoug
post Apr 19 2013, 01:45
Post #32





Group: Members
Posts: 2644
Joined: 24-August 07
From: Silicon Valley
Member No.: 46454



QUOTE
Wait.. doesn't that mean you essentially ship pre-damaged equipment?

You light a match and say "this one works!" and put it back in the box.
No... It's not damaged in any way. It's called burn-in not burn-up! biggrin.gif And, sure hope the headphones don't burn-up during their 1st use!

You may not want to buy a used car, but you probably don't want to buy one that's never been started or road-tested either...

If you are testing bolts, you can do destructive testing (pull or shear 'till it breaks) or non-destructive testing (pull to the specified strength). Obviously you can't sell one that's been destroyed (but you can sell one from the same batch). A bolt that has been non-destructively tested can be sold, and is generally preferred in critical applications. I guess the guys building the new San Francisco Bay Bridge forgot to (non-destructively) test the bolts!

Go to the top of the page
+Quote Post
DVDdoug
post Apr 19 2013, 02:13
Post #33





Group: Members
Posts: 2644
Joined: 24-August 07
From: Silicon Valley
Member No.: 46454



QUOTE (DonP @ Apr 18 2013, 17:41) *
QUOTE (Nessuno @ Apr 18 2013, 16:20) *
DVDdoug, how much of the production cost (not selling price) of the device your company produce is due to QC (burn-in, factory calibration etc...)?


The last time I was doing "shake & bake" testing it took a 25 cent part up to about 2 dollars. This was with hundreds of parts in a rack.
I don't have the numbers... We are not selling "consumer" products. We are manufacturing in small quantities in the USA, so our stuff is not cheap. But, burn-in isn't that expensive. It's just an extra week of inventory-holding time and a some electricity for the heat. The double-testing (before and after burn-in) does about double the test-time. But, that's only a small part of the total labor. The pre-burn test often involves some extra steps, such as programming, and since there are some manufacturing errors and pre burn-in failures to be repaired/corrected, there is often troubleshooting time involved in the pre-burn-in test. This can be significant. If it takes half a day to test 20 units, you might have one failure that takes another half-day to repair,* or maybe you spend a half-day and a PC board ends up getting scrapped. Since post burn-in failures are rare, the 2nd test usually goes faster than the 1st test. So if you look at "technician time", the burn-in and post burn-in test don't actually double the test-time.

Like most small manufacturers, most of our cost is overhead... Direct labor is not significant! The engineers & managers make the "big bucks". biggrin.gif We have about 9 employees (some part time). There are two of us in direct manufacturing (one Assembler and I'm a "Test Engineer" mostly doing technician work), plus one person in materials (purchasing, shipping/receiving & stockroom).


* If you've never worked in manufacturing, you might be surprised to learn that some "brand new" products off the production line have been repaired. I knew it was common in electronics, but I was surprised when someone who used to work for an autombile manufacturer told me she'd done "body work" on the production line! If you are doing high volumes, say making iPhones, you've got to do better and get almost 100% quality without "fussing around" troubleshooting & repairing things.

This post has been edited by DVDdoug: Apr 19 2013, 02:24
Go to the top of the page
+Quote Post
Arnold B. Kruege...
post Apr 19 2013, 20:37
Post #34





Group: Members
Posts: 4014
Joined: 29-October 08
From: USA, 48236
Member No.: 61311



QUOTE (MikeFord @ Apr 18 2013, 19:58) *
Don't we have some type of acoustic memory, a frame of reference to what things are "supposed" to sound like, that may take some time to accommodate a change in that frame of reference?


Do you think! ;-)

IME that is the biggest part of the audio break in myth.
Go to the top of the page
+Quote Post
Arnold B. Kruege...
post Apr 19 2013, 20:51
Post #35





Group: Members
Posts: 4014
Joined: 29-October 08
From: USA, 48236
Member No.: 61311



QUOTE (DVDdoug @ Apr 18 2013, 21:13) *
If you've never worked in manufacturing, you might be surprised to learn that some "brand new" products off the production line have been repaired. I knew it was common in electronics, but I was surprised when someone who used to work for an autombile manufacturer told me she'd done "body work" on the production line!


Right, before mass production, parts were hand fitted during assembly. Mass production was enabled by precise parts that all fit together on the first try.

Some hand fitting was common on automotive production lines through at least the 1960s. One stop on the line was a guy with a bar of lead and a torch, who smoothed over some of the sheet metal joints before painting, for example. The next guy took a few strokes with a file. The next guy had a power disc sander.

I worked on computers near the production lines at Buick in the late 1960s and about 1/5 of the cars took work to get off the end of the line. There were a few cars that were so flawed that they never left the plant and were used for tow and push and the like.

One big difference between Packard and Rolls Royce Merlin engines in WW2 were that the RR engines were all hand fitted, which made field repairs far more time consuming. Packard scrapped that approach for their US production and replaced hand fitting with precisely made parts that just fit, so any field repairs could be performed with off-the-shelf parts that fit into any engine.

The big pay off comes when it is faster to simply make parts right than hand fitting them. Often this involves making parts and then inspecting them and reworking or scrapping the ones that fail inspection.

QUOTE
If you are doing high volumes, say making iPhones, you've got to do better and get almost 100% quality without "fussing around" troubleshooting & repairing things.


We could hope for that to be universal, but there is still a lot of breaking equipment down into subassemblies that are individually tested before final assembly.

For example 100% testing of chips is usually still done by the chip manufacturers.
Go to the top of the page
+Quote Post
pdq
post Apr 19 2013, 21:09
Post #36





Group: Members
Posts: 3426
Joined: 1-September 05
From: SE Pennsylvania
Member No.: 24233



Where I work we use a factor of ten rule. It costs ten times more to fix or discard a defective module once it is assembled into an instrument, and ten times more to fix an instrument at a customer site than to fix it before it ships.
Go to the top of the page
+Quote Post
julf
post Apr 19 2013, 22:20
Post #37





Group: Members
Posts: 283
Joined: 14-January 12
Member No.: 96426



QUOTE (Arnold B. Krueger @ Apr 19 2013, 21:51) *
One big difference between Packard and Rolls Royce Merlin engines in WW2 were that the RR engines were all hand fitted, which made field repairs far more time consuming. Packard scrapped that approach for their US production and replaced hand fitting with precisely made parts that just fit, so any field repairs could be performed with off-the-shelf parts that fit into any engine.


Still, the North American Mustang only become a success in the WWII when the Allison was replaced by the RR Merlin...
Go to the top of the page
+Quote Post
greynol
post Apr 19 2013, 22:24
Post #38





Group: Super Moderator
Posts: 10085
Joined: 1-April 04
From: San Francisco
Member No.: 13167



Let's not drift any further off-topic. Use the PM system or start something in the off-topic forum if you wish to add your two cents on WWII-era manufacturing.


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
MikeFord
post Apr 19 2013, 23:11
Post #39





Group: Members
Posts: 132
Joined: 22-May 04
Member No.: 14241



QUOTE (greynol @ Apr 18 2013, 17:37) *
QUOTE (MikeFord @ Apr 18 2013, 16:58) *
Don't we have some type of acoustic memory, a frame of reference to what things are "supposed" to sound like, that may take some time to accommodate a change in that frame of reference?

Yes and it lasts on the order of a few seconds. Anything beyond that point is prone to being influenced by factors that may not even be related to the actual experience of interest.

This should not be news to anyone who has followed one of the many similar open discussions that exist on the forum.

Not the direction I was thinking about, more like how long does it take before we stop noticing some acoustic variation. Like staying in a hotel and having trouble sleeping due to road noise the first night or two, but after a few days you don't consciously hear it and sleep just fine.
Go to the top of the page
+Quote Post
greynol
post Apr 19 2013, 23:38
Post #40





Group: Super Moderator
Posts: 10085
Joined: 1-April 04
From: San Francisco
Member No.: 13167



Ok, that makes sense too.


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
MagR
post Apr 20 2013, 09:18
Post #41





Group: Members
Posts: 14
Joined: 17-March 13
Member No.: 107264



Hi

I'm the OP - I've been reading all your posts and it has been very informative. I've also looked at some of linked articles and it seems that break in may exist but is pretty minor. I'd like to update on two matters which might affect my position:

1. I was originally using a Fiio E7 docked into the top of my E9 (had been using for over a year for gaming audio). About two weeks after getting the HD650 I docked the E7 into the E9 using the normal line in for the amp (the wobble in the dock port had been annoying me for ages but never got round to using the adapter for the E7 which allowed me to do this before). I wonder if this inadvertently cured the problem - I was switching the set up around for a different reason. I'm now using an O2 with ODAC inside so this won't occur again.

2. I got a pair of AKG K701's yesterday and have listened to them for hours. They seem fine - nothing sounds out of tune or harsh at all. They sound different to the HD650 but both sound good and tuneful/musical.

In the light of the above I'm inclined to think my docking error probably caused the problem I put down to break in since it seemed to clear up later.

Thanks for all your help.

Regards

Mag
Go to the top of the page
+Quote Post
dhromed
post Apr 20 2013, 10:31
Post #42





Group: Members
Posts: 1328
Joined: 16-February 08
From: NL
Member No.: 51347



QUOTE (MagR @ Apr 20 2013, 10:18) *
both sound tuneful/musical.

You need to understand that these words don't mean anything.
Go to the top of the page
+Quote Post
Arnold B. Kruege...
post Apr 20 2013, 16:20
Post #43





Group: Members
Posts: 4014
Joined: 29-October 08
From: USA, 48236
Member No.: 61311



QUOTE (dhromed @ Apr 20 2013, 05:31) *
QUOTE (MagR @ Apr 20 2013, 10:18) *
both sound tuneful/musical.

You need to understand that these words don't mean anything.


To clarify, exactly what those words mean to everybody but their author is highly variable.

I know for sure that tuneful means something quite different to people who are musicians and people who are music listeners but not musicians.
Go to the top of the page
+Quote Post
markanini
post Apr 20 2013, 20:00
Post #44





Group: Members
Posts: 552
Joined: 22-December 03
From: Malmö, Sweden
Member No.: 10615



F*ck the effect of break-in. OP is claiming his headphones are changing the pitch of the recording, why does that sound completely nuts?
Go to the top of the page
+Quote Post
greynol
post Apr 20 2013, 20:52
Post #45





Group: Super Moderator
Posts: 10085
Joined: 1-April 04
From: San Francisco
Member No.: 13167



Another term was added to the placebophile lexicon.

PRAT -> PRAPT

???


--------------------
Your eyes cannot hear.
Go to the top of the page
+Quote Post
Yaztromo
post Apr 21 2013, 09:52
Post #46





Group: Members
Posts: 236
Joined: 28-July 03
From: England, UK
Member No.: 8031



QUOTE (extrabigmehdi @ Apr 18 2013, 12:21) *
The guy Tyll from innerfidelity measured the effect of "break in".
From what I've understood of his article, the changes are too small, and he didn't want to conclude anything .
What I see, there are less changes in the frequency response with time, than there are differences between left & right.
http://www.innerfidelity.com/content/measu...headphone-break


On every well thought out piece of audio blogging, the first comment will be from some nut job that still believes in the magic. This one is no different.

Comedy rage inducing gold.
Go to the top of the page
+Quote Post
MikeFord
post Apr 21 2013, 10:19
Post #47





Group: Members
Posts: 132
Joined: 22-May 04
Member No.: 14241



QUOTE (greynol @ Apr 20 2013, 12:52) *
Another term was added to the placebophile lexicon.

PRAT -> PRAPT

???

Whats not to love about placebo? Other than expense.
Go to the top of the page
+Quote Post
db1989
post Apr 21 2013, 12:34
Post #48





Group: Super Moderator
Posts: 5275
Joined: 23-June 06
Member No.: 32180



The fact that people are deluding themselves and others unnecessarily? Assuming we’re talking about faith-based and/or pseudoscientific concepts, whose proponents tend to staunchly oppose efforts to evaluate them in a proper way, I don’t really care how good that type of placebo makes people feel. It’s a toxic mindset that hampers their own understanding of the world and, if propagated to others—as many people evidently feel the need to do—spreads those misconceptions as if truth and reduces everyone’s ability to gain an accurate understanding of existence. The ability to collect and transmit knowledge using valid methods is probably the best thing we have going for us as a species; why shouldn’t we be annoyed whenever said methods are subverted/perverted into nonsense?

Um, </soapbox>. This isn’t directed at the OP or anything, but for the record, that’s my idea of “What[’]s not to love about placebo”.
Go to the top of the page
+Quote Post
andy o
post Apr 22 2013, 06:38
Post #49





Group: Members
Posts: 1333
Joined: 14-April 09
Member No.: 68950



QUOTE (DVDdoug @ Apr 18 2013, 11:33) *
4. Why is it that the product always seems to improve with burn-in? Why doesn't it sometimes get worse?

I think this one is the most compelling for it being psychological rather than physical.
Go to the top of the page
+Quote Post
andy o
post Apr 22 2013, 06:53
Post #50





Group: Members
Posts: 1333
Joined: 14-April 09
Member No.: 68950



Placebo is not to be loved, but not hated either. It's to be understood so that people who are told that they may be experiencing it don't immediately feel offended as if you're saying they're nuts. We're all susceptible to it. Ben Goldacre and other MD skeptics have written quite a bit about it, and as it turns out, it usually is more powerful than even many skeptics believe. I was surprised that the color of the placebo pill, for example, can vary its effect. Less surprising is the pill vs. injection form.
Go to the top of the page
+Quote Post

3 Pages V  < 1 2 3 >
Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 31st October 2014 - 23:21