Do recones need a break-in period?

[Altec Best]

I always thought you just mount them in your enclosure and run some tunes through them for a couple weeks :2thumbsup: Good To Go

[Audio_by_Goodwill]

Cone drivers break in, of that I am sure. Fs and Vas will change, and some other parameters. I've measured it, so have many folks I know. I can provide measurements, if you like.

No, not necessary, I'll take your word for it.

You're right tho that they do kinda plateau. Once they get loosened up, then they don't change a lot after that. It's no big deal. The surround and the spider flex and get more supple, that's all.

I just don't see the point, unless you're going to measure the driver and then design a box around those measurements. Then it would make sense to reach that plateau. However, I'd question any break in method that would allow the cone to move excessively. It seems to me that it would be possible to work the driver beyond the point normally reached during playback and end up with equally off numbers as a driver that hadn't been broken in. Please understand that I'm just speculating. I don't have intimate knowledge of the characteristics of the relevant materials.

[aditya]

IMO "panomaniac" is right.

Loudspeakers are electro-mechanical devices, and like any other mechanical device, they have a graph which shifts to a different value after few hours of initial use, which then continues with it for a longer steady period, and again changes that when they are ready to die. So breaking-in really does help in serious/professional cases. I personally always do a breaking-in thing with new drivers. Otherwise everything else suffers while designing something new.

There is also another side to it.....

The coil assembly also gets a kind of a heat/baking treatment which increases its life span, and also slightly raises its high-end power handling capacity. Most pro/studio users always benefit from this. Ofcourse many pro manufacturers always ( or rather should ) heat-treat the motor assembly prior to its assembly.

Regards
Aditya

[bfish]

...I just don't see the point, unless you're going to measure the driver and then design a box around those measurements. Then it would make sense to reach that plateau. ...

That's exactly the reason to do it. As I see it (born out with tests), it only takes about 30 seconds at xMax to get ~as far as it's gonna go. It'll take that much to have the same effect the next time you use them, getting less with frequent use. Even old drivers are best measured after being fully flexed a bit.

[Audio_by_Goodwill]

......it only takes about 30 seconds at xMax to get ~as far as it's gonna go........

That's it? I understood it to be something people would set up and leave running for hours. Maybe that's just over exuberance on their part, although, you did specify xmax, so maybe they aren't pushing them that hard, and therefor taking longer.

[valhallax]

the way i understand it..the original 515, pre-b, took quite a bit of breaking in due to the spyder being very stiff at first, but once broken in a bit they are amazing

[RonSSS]

When I got my reconed 411-8A's back from GPA, I measured the TS parameters. They were not close to what Altec spec'd......so I set one on the bench and ran it with a 10 hz sinewave, about a 1/4" excursion for 2 days.
Re-measured...no difference.
I think driver break-in is bs. Sorry.
Ron

[Panomaniac]

Actually you are the only person I know who has measured, run break-in, then measured again and found no difference.
Your procedure certainly seems right.

Strange....

[RonSSS]

The funny thing was, the TS paramaters measured closer to a 416 than the 411, so I designed the enclosures accordingly. I used them as sub woofers, vented. The orig 411 was meant to be a sealed box woofer. I went with 8 cubic feet with 6" round ports about 6" long. I tuned the boxes to 20hz. Worked great.
Mine were the first pair of 411 that GPA did, they may have different parts now.

Here is a photo of the subs with the duplexes.



Simple MDF, well braced.

BTW.....probably the best sound from Altecs I have ever made........

Ron

[Nipper]

Dont forget the break in period for the monster speaker wire.... Keep it under 10 watts for the first half hour.
:coffeedrinker: