Driver Break in - Fact or Fiction? - Page 4 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #31 of 98 Old 08-19-08, 02:10 PM
cyclopsitis
Inactive
 
Posts: n/a
Re: Driver Break in - Fact or Fiction?

I have a speaker tester and I've noticed that parameters change after the speaker has been used. I noticed one person said it is a question of what you can hear or measure? For me because I design speakers I have been able to test many of the same drivers side by side! I know that I can hear an audible difference after about 20 hours. The drivers tend to even out and loose a bit of that "hiss" sound on "s's" and "t's". I know of a few speaker manufactures’ that only test their raw drivers after they have been brought to "normal" operating conditions. It is then that they administer the tests that you will see on the data sheets.

As for the person above here who has posted a question. Our ears can trick us much like a magician can trick our eyes. It has been a while but if I remember correctly. With psychoacoustics if a person hears a set of speakers in a show room the last ones they hear will always sound the best. Finally, what ever model is being "pushed to sell" is turned up the loudest. This will make them sound the best in the show room.

However, no matter how "good" they sounds in the show room your room is much different. I think a combo of psychoacoustics and the fact that a certain type of speaker and placement will drastically affect the sound quality in your room probably play a bigger roll in the if someone takes their new speakers back to the store. If people are truly buying high end speakers most high end manufacturers have already played their speakers to what they call the "break in" point. With my business I play every set of speaker for at least 30 hours before I’m happy with them. Besides it gives me the time I need to perfect them before I ship them.

K
Sponsored Links
Advertisement
 
post #32 of 98 Old 08-19-08, 08:20 PM
Bill
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 185
Re: Driver Break in - Fact or Fiction?

Driver break in is real, especially with woofers. It takes a good 24 to 72 hours of use for the suspension and spider to loosen up and for the driver fs to come down to spec. OTOH I've seen it claimed by some speaker (not driver) manufacturers that up to 400 hours of use is required for full break in. What really happens in that instance is that you get used to how they sound and no longer notice that they aren't very good.
Bill Fitzmaurice is offline  
post #33 of 98 Old 08-20-08, 02:39 AM
Elite Shackster
Steven
 
Join Date: Jun 2007
Location: Midwest
Posts: 1,405
Re: Driver Break in - Fact or Fiction?

I disagree. My skeptcism of the way my HT sound only gets more critical, and not the opposite. That does make since they would recommend such however because by 400 hours they may have forgotten what they wanted it to sound like to begin with.
thewire is offline  
 
post #34 of 98 Old 08-20-08, 05:08 AM
Shackster
andru
 
Join Date: Aug 2008
Location: Kewarra Beach
Posts: 14
Re: Driver Break in - Fact or Fiction?

I think it is really possible to hear the difference in a "brocken in" driver, especially a bass or say a 10" driver.
As a guitarist with a bunch of old tube amps I am always looking for a way to get a vintage (used) sound from a new speaker or driver.
This topic brings to mind my method of aging a speaker... for better or worse, (if it breaks, get another one until you get it right...)
well anyway...
Recently I wanted get a vintage sound (more bass/low mids from a pair of new 10" speakers) when I put the two new celestion 10" speakers in an open backed cabinet, there was just no gut wrenching low end, just a sort of honky hi mid...
so the old musicians trick/methodology goes something like this...

Take the speakers out of the box, sit them on their backs and pump a reasonably low tone through them. Something that makes the speaker really work hard, but don't kill it....by over doing it. (if it's a 10" don't go too low with the sine wave...)

Using some kind of protective gloves for hands and skin and the wife's new carpet.... paint some acetone around the rims, evenly... leave them to cook (play for a while... how long is up to you.)
But you may well notice a change in the timbre/quality of the tone after a while....
test them again to see if the bass end has improved/changed. If not try again ...maybe longer... more acetone (but again... don't over do it.)
It worked for me, and is how I always used to break in the new Jensen 10" to get the real blues warmth...
Now how this will translate to HiFi is anyone's guess, but it is fun, however my cat, wife and children were not impressed.
It could be something you might try on a cheap sub speaker or two... just to get the hang of it....
and to see if you can tell the difference or even improve the beastie.
Thanks for listening.
Andru
andru is offline  
post #35 of 98 Old 08-20-08, 08:29 AM
Bill
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 185
Re: Driver Break in - Fact or Fiction?

Quote:
andru wrote: View Post

Take the speakers out of the box, sit them on their backs and pump a reasonably low tone through them. Something that makes the speaker really work hard, but don't kill it....by over doing it. (if it's a 10" don't go too low with the sine wave...)
That should be standard proceedure with all woofers. I break mine in with a 20-25 Hz tone at 8volts for 24 hours. Then I measure the fs to be sure it's at spec before mounting the driver. With mids and tweeters break in prior to mounting isn't as critical.
Typically a woofer fs will run at least 10% higher than spec prior to break-in.
Bill Fitzmaurice is offline  
post #36 of 98 Old 08-20-08, 01:07 PM
Senior Shackster
 
looneybomber's Avatar
Looney
 
Join Date: Sep 2006
Location: Topeka, KS
Posts: 430
My System
Re: Driver Break in - Fact or Fiction?

Quote:
Bill Fitzmaurice wrote: View Post
That should be standard proceedure with all woofers. I break mine in with a 20-25 Hz tone at 8volts for 24 hours.
I used to do something simliar (used a sweep from 15-25hz or so), but now I try a different method. High power, short duration with this song. It has a lot of 20-30hz energy.
YouTube - SDX-15 video 2
It gives a good stretch with a short enough duty cycle to keep heat from being an issue.

This method is a different story though.
YouTube - Fs3 Sub Speaker best Excursion Prototypes
looneybomber is offline  
post #37 of 98 Old 08-21-08, 12:16 AM
Shackster
andru
 
Join Date: Aug 2008
Location: Kewarra Beach
Posts: 14
Re: Driver Break in - Fact or Fiction?

I guess so, but a lot of people probably never remove the speaker from the box/cabinet... if it's pre installed...
some small thing called warranty I guess. But.. well, I am a tinkerer... some are... and some not.
I call it freedom to experiment... but I'm off track... sorry.

Andru
andru is offline  
post #38 of 98 Old 08-21-08, 01:01 AM
Senior Shackster
 
Join Date: Mar 2008
Posts: 349
Re: Driver Break in - Fact or Fiction?

I had a pair of vifa 7" midbass woofers I put in the doors of my jeep. I was really upset with the way they sounded at first. They had no depth to them at all and didn't play very loud.

So I figured I would give them some break in time.
I would spend hours in the parking lot of our apartment just listening to music in my jeep.

I noticed that after about 35 hours...(yes I kept track) they sounded much cleaner...and had really nice definition, and played pretty low.

I don't know the math behind the electronic side of this...but from an audible standpoint I think that yes it does make a huge difference.

My dad used to work at a ultra highend audio store and they did a break in process on all the speakers on the floor were they played pink noise through them for 48 hours on a test bench.
BrianAbington is offline  
post #39 of 98 Old 10-17-08, 09:16 AM
Bill
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 185
Re: Driver Break in - Fact or Fiction?

Quote:
SQCherokee wrote: View Post
I don't know the math behind the electronic side of this...but from an audible standpoint I think that yes it does make a huge difference.
.
The math is unimportant. The result is major, about the same as how comfortable a pair of leather shoes are after a few months of wearing them compared to when they were new, and for exactly the same reason.
Bill Fitzmaurice is offline  
post #40 of 98 Old 10-17-08, 11:47 AM
Kevin
 
Join Date: Nov 2007
Location: Port Angeles, WA
Posts: 1,026
Re: Driver Break in - Fact or Fiction?

I'll stay away from the subjective side of this debate but the following happens with suspension components.

The Cms will rise after some initial break-in period (Cms is distance of movement/unit of force so larger means that the suspension gets softer). How much, depends upon the suspension of the driver and the construction of the spider & surround. On subwoofers, you can see about a 10% change in Cms with break-in.

One thing to note, the suspension of a driver is the loosest spec'd parameter. Spider Cms is typically +/- 10-20% so there is a variation in normal production runs. The good thing is it doesn't matter much. If you change Cms and remodel the driver there just are not large changes in the final response of the system so difference due to production tolerance or break-in, are not likely to be audible.

Another thing to consider is that the spider will actually stiffen after sitting. It goes through another micro break-in period during every use. There is also a static coefficient of friction, that makes the initial movement of the spider more difficult than dynamic operation. And of course, all suspensions change with stroke so you get a higher Cms as the cone leaves center. Good progressive ones give you a good range without large changes in Cms.

Tempeture is also a significant contributor. I've taken a halogen light out and shined it on some drivers to loosen them up for measurements in my cold warehouse. It easily can make 10-15% differences.

All of these things are very easy to measure (except maybe the dynamic vs. static) so there is NO controversy about these types of changes. The significance of them are often greatly exaggerated but their actual occurance is beyond question.

The claims of electrical break-in and it's audibility is another topic. Suffice it to say that there is no credible research showing any correlation with electrical break-in. That is, nobody has proven any correlation between a wire that has had a signal running through it for a given period of time and one that hasn't. There doesn't seem to be any credible research showing that cones break-in after a given period of use either. By credible, I mean something that is backed by research with peer review. There may be some self appointed gurus who can show you a waterfall with changes but there isn't any studies that show any meaningful correlation with audibility. Suffice it to say that the small changes are of a magnitude to be WAY below what we typically consider audible.

I'd say the most likely way to describe people's experience with break-in is due to psyco-acoustic mechanisms rather than physical ones. In other words, it is mostly between your ears rather than in the system. That may not be a comfortable thought, because I've heard differences after break-in also, but given the information we have it is the most credible explanation.

Kevin Haskins
Exodus Audio
www.diycable.com
Kevin Haskins is offline  
Reply

Bookmarks

Tags
break , driver , fact , fiction

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome