Breaking in a subwoofer

[t&t tech]

If you actually need to do that for any subwoofer, you probably should be investing your money in better subwoofers

That statement is absolutley positively incorrect!

The info provided by rovin from the dd site is quite right! Any one remotely familiar with audio will know this! It doesn't matter what sub you have the laws of physics apply to all, in one and the same manner! Doh worry boy Mr Rovin yuh eh mad! LOL!

[Firewall]

i think that also since the suspension is stiff post production, the cooling of the coils is decreased and if you throw the full power or "trini" power (doh worry bai, it underrated) one time the coils may overheat and may be damaged

[t&t tech]

Yes! Spot on!

[Brian Steele]

so if i understand what ur saying i cud buy a brand new sub rated 1500wrms just drop it in a box designed for it (proper install of course) & play it right away with full the 1500wrms without any worries of damaging it ???

Continuously at its rated rms powerhandling? No. I would not advise that be done for either new or supposedly broken-in subs. However, as most of us listen to music and not continuous sine waves, and the average power supplied to the subs when playing music is likely to be 1/5 or less the peak power, I think you should be fine playing new subs at the same level as their supposedly broken-in brethren.

so um :

taken from DD site :

We recommend to allow at least several weeks of playing time to break in DD Woofers, full break in may take many months. DO NOT play subwoofers at max amplifier power in the first couple of days, give the suspensions a chance to loosen up. As the suspension breaks in, the subs will play lower and louder.

whats up with this ? ...

LOL - ask them to explain WHY a subwoofer would handle MORE power when its suspension "breaks in". Better yet, ask them for actual test results that support their position. And how is that power rating derived, BTW? Until those can be shown and explained, my BS-Detector is blinking .

FWIW, frankly, if a subwoofer manufacturer told me that it would take "several months" to fully break in the suspension for their subs, I would look elsewhere. Why on earth would I want to spend my $$$ than have to wait several months to get the best performance from my subwoofers?

Perhaps their advice is really geared towards ensuring that their subs aren't blown up by those who are uninformed enough to believe that just because a subwoofer is rated at xW rms that you can drive it continuously at xW rms at any frequency in any alignment. Perhaps their advice is given to basically suggest that an abundance of caution should be exercised .

[t&t tech]

Nowhere in the quote from the dd site did it say anything about the speaker being able to handle more power after being broken in! it makes mention of not playing the sub at max until you have given the speaker a chance to loosen up!
No sub needs to be broken in to prevent it from being damaged!
As said in the quote and one of my earlier posts! This time allows the speaker to loosen up and become more compliant to the frequencies and thus resulting in better sound!
This isn't an arguement or a law of audio! It's simple physics! It hapens naturally! Whether or not you like it!

[nervewrecker]

Brian Steele, you have to understand where rovin is comming from as well.

I understand the fact that people dont listen sine waves (although I wont doubt that some do) & that the sub will not be seeing the full amount of power from the amp most of the time with audio playback so the sub will be aloowed to be cooled etc & loosen up but trinidadians will mash up ball bearing slug & bulldozer wheel if they get a chance. typical trini mentality as Firewall stated is "it under rated, it calling for more power" so they put bigger amps on the subs. this seems to be the trend nowdays, this is the reason why the sub will be seeing way more power that it would be seeing from an amp that puts recommended power on it.
then you have to take into consideration: how many of them have the subs in the recommended enclosures &/or at recommended tuning frequencies or anything close.
then it have the set who dont have double & tripple the power so they turn the gains & bass boost right up and say that amp have wayy more power that its rated to have, I now reach volume 5 or 6 & hear how the sub getting on, imagine when I turn up the volume more.
they they go down by the nearest rum shop, drink a few beers, turn kant & believe that thier music can go louder (about the same time when they turn irrestible to the opposite sex & the waitress looks like a supermodel) so they turn it up. then the usual story is the sub no good & the amp have real power.

trinis want to put 2 & 3 times the rated power on a sub & expect to jam it with full power one time, like I said ball bearing slug & bulldozer wheel.

[- Rovin's car audio -]

^^^that trini thing is a whole other discussion for another time


DD & other good manufacturers of course for warranty issues wud not want customers to fully power up & F up their new speakers right away which wud ending costing the company time & $


i wud think\hope most ppl by now wud know if u have a rated 1500wrms sub & using a 1500wrms amp on it that the sub wud hardly likely see 1500wrms since music is dynamic & not a continuous flow say like a sine wave


doubt most ppl have the patience to wait mths for their sub\s already installed to break in so if they do some searching online they might come across the "run ur sub free-air with sine waves so it breaks in faster" method , most good installers shud already know this too


imo i still recommend breaking in especially with some of those new powerful subs which have extra stiff spiders : (music speaking of course) ought to to played lesser than its rec rating when its brand new


better safe than sorry than risk messing up a good new sub .....

[t&t tech]

Here is a simple illustration that i came across!
Think about the muscles in your body and exercise! At the beginning you are stiff and unable to flex comfortably! After time you become loose your body can adapt to new excercises easier, as it were second nature!
Similarly with a sub when it's new, its's unable to respond to all the frequencies as it should! As time progresses the sub becomes loose and more compliant, it can adapt to the frequencies (especially the lower ones) easier and as a result sounds better!
All happening naturally without any co-ercion whatsoever!

[t&t tech]

That illustration is just for brian eh fellas! Seems like it kinda difficult for him to grasp nah! So i tryin to help him see!

[- Rovin's car audio -]

t&t tech, thats 1 way of looking at it too



when im telling ppl who ask me i use running shoes as a example - i bet if ur going to run a marathon or any rugged course u wont be wearing a brand new pair of running sneakers ....doubt i need to explain that even further .....

[t&t tech]

I hear yuh Rovin! Daz a good illustration too! By the way slacker jack ah like dah piece ah trini talk dey! LOL

[nervewrecker]

I think I understand what Brian Steele is trying to say guys.

what he is saying is that putting the recommeded power on a sub in recommended enclosure it will not be seeing full power all the time with music playback. the sub will get time to cool & will not be moving like it will if it was hit with a sine wave.
listen to radio for a day & see how much songs make the sub reach full excursion or even get full power from the amp. it will get an occasional thump & boom but not continious.
that is his arguement with respect to breaking in a sub (the fact that it will be broken in anyways from proper use & that its just that some subs have a longer breaking in time than others).

I could speak for myself when I say I have more than twice the recommended power on my sub & it barely gets any jamming from daily use, hit it with a sine wave & the whole car rattles. at volume 15 - 20 with a sine wave I get the same bass response like I get from normal audio playback @ volume 46.

[- Rovin's car audio -]

slacker_jack,


Brian Steele, is a foreigner so u might want to use a bit more clearer way of typing with less trini slangs & splitting up sentences into paragraphs wud make it easier to read & understand it too ....

[nervewrecker]

I hear yuh Rovin! Daz a good illustration too! By the way slacker jack ah like dah piece ah trini talk dey! LOL

what I said is sad but true.

what brian is accustomed to is not what takes place in Trinidad. yes you can put a bigger amp on a sub but it will mean that it will be seeing close to its max power handeling more often than it will be see with a recomended amp. but the its how you use it too, is it for daily use in the car where you listen to it on your way to work & back home or is it where you park up by the rum shop & blast it out from dusk till dawn.

the sub will handle the double power at the low volumes for daily use better than it will outside the rum shop whole night.

if anyone begs to differ take a look in the classifides & see the kind of amps people use on subs. take a pass in a car show & see that people using insane amounts of power on subs (way more than they were built to take). at the end of the day is how you use your system, the car show system that plays for 45 seconds 3 times for the night will outlast the one that plays dusk till dawn friday, saturday & half day sunday at full volume.

[Brian Steele]

Nowhere in the quote from the dd site did it say anything about the speaker being able to handle more power after being broken in! it makes mention of not playing the sub at max until you have given the speaker a chance to loosen up!
No sub needs to be broken in to prevent it from being damaged!
As said in the quote and one of my earlier posts! This time allows the speaker to loosen up and become more compliant to the frequencies and thus resulting in better sound!
This isn't an arguement or a law of audio! It's simple physics! It hapens naturally! Whether or not you like it!

Funny thing about physics - usually hypotheses need to be confirmed by actual measurements before they become accepted theory .

I've yet to see ANY measurements that suggest a driver's parameters change significantly after break-in. In fact, the only published test that I have seen actually DISPROVES the hypothesis that "break-in" makes a significant difference, and that's the one Tom Nousaine did with the Dynaudio sub for CSR several years ago.

Ok, let's apply some logic to the situation. ANY change in compliance that results in a significant change in how the sub sounds WILL be reflected in a significant change in the driver's measured T/S parameters, end of story. So, it should be very easy to observe and quantify this "big change" that occurs during break-in by simply comparing the driver's measured T/S parameters while new to its measured T/S parameters a few months down the road, right?

So guess what - I just did my own test using those test guidelines. I've got some Infinity subs in my ride at the moment that I purchased almost a year ago. I measured the T/S parameters of one of the subs back when I'd just purchased them, and I just yanked out one and measured its T/S parameters a few minutes ago. See results below:

New driver measured specs :
Fs : 18.8 Hz
Qms :6.26
Qes : 0.49
Qts : 0.457

(see http://www.diymobileaudio.com/forum/diy ... e-see.html for the thread where these specs were published)

Current measured specs:
Fs: 18.8 Hz
Qms: 5.86
Qes: 0.50
Qts: 0.46

(I can send you the captured image from WT3 if you don't believe me, LOL).

I didn't measure Vas as I didn't think it necessary - any change in compliance should show up as a change in Fs. In any case, the Qb of my sealed box is still basically the same (it would shift dramatically if Vas shifted dramatically).

Conclusion: The changes are minor and well within usual limits. This suggests NO significant change in the subwoofer's parameters, after several months of operation (and I do tend to be heavy on the bass knob at times ).

Now, if I can get consistent performance like this from a cheap US $100 subwoofer, why on earth would I spend $$$ more for inconsistent performance from another manufacturer's subwoofer?

[Brian Steele]

Here is a simple illustration that i came across!

That illustration would only make sense if the surround and spider, like the muscles in your body, are living tissue which continuously adapts and changes based on the amount that they are exercised. This is of course clearly not the case with your typical subwoofer, unless Cyberdyne Technologies has started manufacturing one to go with their latest Terminator models .

[Brian Steele]

t&t tech, thats 1 way of looking at it too



when im telling ppl who ask me i use running shoes as a example - i bet if ur going to run a marathon or any rugged course u wont be wearing a brand new pair of running sneakers ....doubt i need to explain that even further .....

You're comparing chalk and cheese here - the materials used in a "running shoe" are not the same as the materials used for subwoofer's spider and surround. Same family perhaps, but not the same .

[Brian Steele]

slacker_jack,


Brian Steele, is a foreigner so u might want to use a bit more clearer way of typing with less trini slangs & splitting up sentences into paragraphs wud make it easier to read & understand it too ....

LOL - don't forget I used to live in Trinidad for quite awhile . When people hear me speak, one of the first things they usually ask is "are you from Trinidad?"


B.

[Brian Steele]

what brian is accustomed to is not what takes place in Trinidad.

LOL - Trinidad doesn't hold the patent on that kind of behaviour. I used to observe a lot of it in Grenada too . Things have cooled down a bit though, now that big music installs in the minibuses is now banned.

[t&t tech]

Oh well! What more can i say! That theory brian is accepted by installers of a vast array locally and on an international scale! Where are you from brian? Are you an installer of car audio? If you don't mind me asking!

[- Rovin's car audio -]

t&t tech, thats 1 way of looking at it too



when im telling ppl who ask me i use running shoes as a example - i bet if ur going to run a marathon or any rugged course u wont be wearing a brand new pair of running sneakers ....doubt i need to explain that even further .....

You're comparing chalk and cheese here - the materials used in a "running shoe" are not the same as the materials used for subwoofer's spider and surround. Same family perhaps, but not the same .

never said d materials are the same but d principle is



btw - are u really the owner of that site & were u born here or did u work here in trinidad ? ....

[Brian Steele]

Oh well! What more can i say! That theory brian is accepted by installers of a vast array locally and on an international scale! Where are you from brian? Are you an installer of car audio? If you don't mind me asking!

Well, at one time a "vast majority" used to think the world was flat too .

The lessons learnt while obtaining my engineering degree taught me to observe and measure to confirm correlation between theory and reality, and not to accept something simply because other people say so.

So far, Tom Nousaine's measurements, and my own measurements just performed for your benefit indicate little or no change in parameters. Have you seen any similar tests performed that indicate otherwise, or are you just accepting someone else's word for it?

As for where I'm from, I was born in Grenada, but spent a good portion of my life in other islands, and a good portion of that in Trinidad, where I did most of my schooling (up to BSc in Electrical Engineering from UWI, specializing in Telecoms and Control Systems). I do my own car audio installs and assist with others when I have the time (not much these days, unfortunately). I suck at fabrication as well, so I try not to get too involved in that .

[Brian Steele]

btw - are u really the owner of that site & were u born here or did u work here in trinidad ? ....

Yes, I'm the owner of www.diysubwoofers.org. I gave a brief bio of myself in my previous message.

[- Rovin's car audio -]

cool bro ...

[Vtec Vigilante]

i followed the method given in the link

http://www.the12volt.com/installbay/for ... PN~1~TPN~2

Here's a procedure I learned that is fairly simple to use to break in a woofer. If you are installing your own woofers, be it for car or home use, and have found this thread because you're the type who wants to go about the installation systematically, covering all bases, then this procedure is for you:

You need a test tone CD (here is a download) with a 10 minute track of the tone that corresponds with the Fs of the woofer. You need to be able to hang the woofer up in mid air, through one of the mounting holes in the frame, letting it hang freely. There should be no walls close to the woofer, and the woofer certainly shouldn't be laying on the table on its magnet (as you often see in videos). The nearby table or wall acts to compress the air behind the cone so avoid those types of disturbances.

The idea is to play the sine wave tone through the woofer at resonant frequency in free air. A very slight amount of power will enable the woofer to move at full excursion. You have to first find out what the Xmax is so that you can look at the excursion and gauge (by eye) the approximate excursion you're putting the woofer through. A subwoofer with a one-way excursion of 12 mm would look like its moving about an inch as the voice coil moves back and forth. You'll note that you are allowing only a few watts of power to reach full Xmax, so be careful with the volume control.

If you're working with a car subwoofer, you can prop the trunk lid and hang it from that. If you're working with a home sub, you can hang it from the ceiling of the room near the amplifier. Play the tone at Fs, watch the cone movement while adjusting volume, and let it flap and whirrr for the 10 minute period. It will sound more like a fan than a subwoofer. Allow 10 minutes cooling time, then run it again a few sets. Your woofer is now broken in.

There is only a small percentage of DIYers who will go through this procedure. They are the ones who make sure they have a test tone CD for setting gains, who make sure they damped all the sheet metal while the car is torn apart, who made sure they grinded all the paint off the metal before securing the ground wire. This is just another of the steps to ensuring that when you are ready to debut the system, it will sound the way you had hoped it would.

This is true..but to my knowledge, the DD Subs..has thier own way of breaking in thier woofers....



This is what they recommend for thiers subwoofers :

We recommend to allow at least several weeks of playing time to break in DD Woofers, full break in may take many months. DO NOT play subwoofers at max amplifier power in the first couple of days, give the suspensions a chance to loosen up. As the suspension breaks in, the subs will play lower and louder.After you give the woofers a chance to break in (you'll know when this happens because the woofers will be playing lower and louder) you can start to look at port changes to alter the sound to your personal taste and your vehicles acoustic loading conditions.

[Brian Steele]

One more thing on this subject - the "power rating" given by a car audio manufacturer for their subwoofers is likely more marketing-speak than anything else. Don't believe me? Ask them how they came up with the rating .

So, if the typical car audio subwoofer "power rating" is questionable, any sort of procedure that's based on this rating should be subject to question as well.

[t&t tech]

Me personally! No i don't have any tests to prove this! Never had the cause to! However, i personally interact with audio enthusiasts of a calibur way superior to myself, the little i do know on this topic was imparted to me from a personal speaker designer and audio installer, with over fourty years of knowledge under his belt, backed by some of his colleauges who i also interact with! The sticky under the headings, So you think you know bout sounds, it makes mention of an audio enthusiast by the name of dan wiggins, I interact with guys who have been personally taught by him! Who have the experience and the skills to back whatever they teach!

P.S. Just so you know had people ever enquired of a simple book known as the bible which existed whilst the "vast majority" believed the world was flat, they would have seen that the bible states, the world is a sphere and hangs on nothing! check it!

Compare the people who believed that back then to this argument, the facts are present, yes, just some people believe "ignorance is bliss".

I out fellas, this thing just plain stretching now! Allyuh have ah good one! See y'all around.

[Brian Steele]

So you think you know bout sounds, it makes mention of an audio enthusiast by the name of dan wiggins, I interact with guys who have been personally taught by him! Who have the experience and the skills to back whatever they teach!

LOL, I've communicated with Dan via e-mail a few times, and via various forums at other times. I even have two of his Adire Audio Shiva subs. Guess what - the specs of those subs didn't shift significantly either, and this is after years of extended play. Ok, one shifted, but that's only after I cut the dustcap off .

In any case, I really couldn't care less WHO proclaims that as gospel. Show me the facts, the measurements that back up the posturing, or the lights on my BS detector will keep blinking away whenever that subject comes up... .

[Brian Steele]

Here's what Tom Nousaine had to say about "break-in" of subwoofers in his 1997 CSR article:

"The bottom line: Based on this test, break-in had no effect on real-world performance. [] breaking in a high-quality driver has no more effect on performance than ordinary sample-to-sample variations among consecutively manufactured drivers.

Consider that speakers are made from a bunch of electromechanical parts that can all vary slightly. When these parts are assembled, we get speakers with bigger sample-to-sample variances than any change caused by break-in.

If you think about it carefully, the only thing that can change significantly with break-in is the compliance of the speaker. Human beings get bigger and stronger when they work out; speakers don't. Exercise won't change the moving mass of the system. It won't change the magnet or the motor strength. And it doesn't change the voice coil, the pole piece, or the top plate. A change in compliance produces a lowered Fs and an increased Vas, which are exactly offsetting in both a mechanical and a mathematical sense. This means that changes - when they can be confirmed - result in exactly the same speaker design and identical performance with or without break-in".

He goes on to say the following:

"In fact, the concept of a component break-in often turns out to be a clever merchandising tool. When you complain about the sound of your new Godzilla speakers, the salesman tells you that they'll need extended break-in to sound their best - thus encouraging you to keep them for a little while longer".

...and...

"It's a well-known fact that humans lose sensitivity to a stimulus with continued exposure. For example, you only hear a fan just after it's been turned on or off. With continued exposure, we equalize ourselves to our environment; given time, we just fill in the blanks and tune out the peaks. Extended break-in simply gives you time to equalize yourself to the speakers and may prevent a manufacturer from having to deal with a costly return.

Break-in periods allow normal adaptive changes in the listener to masquerade as changes in the product. "

...and finally...

"There's nothing inherently wrong with breaking-in your speakers. It just doesn't lead to design enhancement or an improvement in performance."


B.

[3stagevtec]

I've yet to see ANY measurements that suggest a driver's parameters change significantly after break-in. In fact, the only published test that I have seen actually DISPROVES the hypothesis that "break-in" makes a significant difference, and that's the one Tom Nousaine did with the Dynaudio sub for CSR several years ago.

Ok, let's apply some logic to the situation. ANY change in compliance that results in a significant change in how the sub sounds WILL be reflected in a significant change in the driver's measured T/S parameters, end of story. So, it should be very easy to observe and quantify this "big change" that occurs during break-in by simply comparing the driver's measured T/S parameters while new to its measured T/S parameters a few months down the road, right?

So guess what - I just did my own test using those test guidelines. I've got some Infinity subs in my ride at the moment that I purchased almost a year ago. I measured the T/S parameters of one of the subs back when I'd just purchased them, and I just yanked out one and measured its T/S parameters a few minutes ago. See results below:

New driver measured specs :
Fs : 18.8 Hz
Qms :6.26
Qes : 0.49
Qts : 0.457

(see http://www.diymobileaudio.com/forum/diy ... e-see.html for the thread where these specs were published)

Current measured specs:
Fs: 18.8 Hz
Qms: 5.86
Qes: 0.50
Qts: 0.46

(I can send you the captured image from WT3 if you don't believe me, LOL).

I didn't measure Vas as I didn't think it necessary - any change in compliance should show up as a change in Fs. In any case, the Qb of my sealed box is still basically the same (it would shift dramatically if Vas shifted dramatically).

Conclusion: The changes are minor and well within usual limits. This suggests NO significant change in the subwoofer's parameters, after several months of operation (and I do tend to be heavy on the bass knob at times ).

Now, if I can get consistent performance like this from a cheap US $100 subwoofer, why on earth would I spend $$$ more for inconsistent performance from another manufacturer's subwoofer?

This evidence has changed my thinking about subwoofer break in! Can't argue with facts!

Thanks for the info..