relation between power handling and x0ver pt

[Daniel-A]

I know if i xover a tweeter at 4000hz it can handle more power than at 1000hz. But is there a rule other than using computer simulation ?

Daniel

[Mr Evil]

It depends on the type of music. There are various graphs and tables floating around out there somewhere. They all give different values but will give you some idea. I'm afraid I don't have any links, but I do seem to have a graph saved here, which I have attached (I have no idea where it came from originally).

[AndrewT]

Hi,
In terms of heat dissipation using these graphs or look up tables will give reasonable predictions.
But I believe that the Vpk requirement for the treble unit is not well predicted by these methods.
Can I suggest you find some sources for the voltage drive requirement, but in the meantime try applying a factor of 2 (maybe even as high as times 3) to the voltage (=4 to 9 times the power) after choosing your xover point.
Another factor affecting powerhandling is the steepness of the xover rejection out of pass band. eg. a 4pole 4kHz tweeter will accept more power than either a 2 pole or a single pole 4 kHz version.
regards Andrew T.

[5th element]

Actually its not up to power handling really that much with a tweeter. Yes you have the power split as shown by Mr evil, but if you look at that graph at say 2khz representing a low xover and 4khz representing a high xover the difference in the % of power it handles is only about 6%.

What its all mainly about with tweeters is where its free air resonance is and what its excursion capabilities are.

The lower you cross the more excursion a tweeter requires because its having to handle more low frequency material. If the excursion goes out of the tweeters xmax distortion rises and the sound begins to deteriorate. If resonance is approached the excursion then begins to increase because of that. Ferrofluid cooled tweeters have a damped resonance and are less affected by this, tweeters like the XT25 and Scans revelator dont have ferro and are more at risk from this.

Tweeters tend to have about a 10 watt (maybe more maybe less) power handleing, this means they can handle 10 watts of power. This means you can put a 10hz sine wave or 4000hz sine wave through the tweeter @ 10 watts and the tweeter will remain within its thermal limits and not fail because it gets too hot. But at 10hz the tweeter is likely to exceed its linear xmax so will sound terrible, but in this case is likely to suffer mechanical failure.