- Posted by Robert Bastani (M) on October 20, 2005 at 03:53:45
In Reply to: Thoughts on Break-In of Bastanis Drivers posted by Lynn Olson on October 19, 2005 at 23:42:21:
Hi Lynn,thank you for your in- depht thoughts about the burn- in of the widebands, i agree we have to do a pre- burn- in for the widebands.
The two aspects of burn- in you named can be solved by your method, i will discuss this with Bill. The maximum power- input to the widebands
depends on the signal. When you allow frequencies below 30Hz the voicecoil is cooled by it`s movement, then only the maximum- excursion is important for not- destroying the driver. The maximum- excursion for a 48 hours burn- in (imho better than 24 hours) should be setteled at around 4-5mm max. in each direction (max. 1 cm total), the cone can move more than 2 cm without mechanical crashing the voicecoil but better stay in a save range on permanent signal. Also the woofers need a burn- in to soften the suspension, maybe using the second channel of the power- amp for this is fine.
The re- forming of the cone- and glue- structures is also done by this method and i am shure that Prometheus can play music (also the cap, tweeters, cables and soldering- points need some signal and the mechanical de-stressing of mounting needs also some time)after a few hours when the assembling is finished. This method will help to make it much easier for customers.
There is a third aspect of burn- in regarding the Prometheus- widebands which can`t be solved by on a short string, doesn`t matter which method: The cones are flexing over a wide frequency- range, the re- forming of the structures can be done by your method but not the softening of the cone- structures in the microscopic range which is also very important for listening. This microscopic flexibility is needed for all the fine informations which doesn`t result a movement of the whole cone- surface. When the cone is too stiff in this range it can not follow the microscopic signals, like violins or guitars when new. It takes around 6 month until this cone- behaviour is stable and there are many customers who report that they get music out of the speakers relatively quick and then they thought there is no more change in sound until "the one day" they listened to the music and there was only music left, no more hifi- sound at all and every customer who reported this rated the change in sound very high.
My method of cone- treatment to achieve the flexing behavoiur is matched to this point to get 100% out of them.
Following my experiences i would rate the sound- quality of a new Prometheus wideband- driver at 40%, when the high- level burn- in is done they are at 85%, to achieve the 100% it needs time, i haven`t found a method to speed up the fine burn- in but the drivers don`t need high levels for this and also with your method for the high- level burn- in customers can listen to their music on a satisfying level after a few hours.Thank you again for your thoughts and working out a method on this string, it will be a big step ahead!
Regards
Robert Bastani
