power response and acoustical phase

[crazyhub]

Hi all,

To the forum's theorists:

Does it exist an obvious/direct relationship between a speaker's power response and its summed acoustical phase?

And between power response and each acoustical phase of the drivers? In other terms i.e. does the difference between the angles of the phases of two drivers at Fx and/or on the overlap have any importance on the power response?

Thanks

[JLH]

Yes, if the phases are not aligned, then there will be a dip in power response.

[gedlee]

Originally Posted by crazyhub

Hi all,

To the forum's theorists:

Does it exist an obvious/direct relationship between a speaker's power response and its summed acoustical phase?

Thanks

No, none that I can think of.

[john k...]

There are two basic cases to consider. If the sources are acoustically close together (a small fraction of the wave length at the crossover frequency, then the power response will be identical to the system frequency response (assuming the sources are omnidirectional). There is no effect of system phase or the individual phase of the crossover. For example any odd order Butterworth or even order LR crossover would yield flat response and flat power response. Any crossover that sums flat would yield flat power response.

The second case is when the sources are acoustically far apart. In that case, flat power response is obtained only with any order Butterworth crossover (to the best of my knowledge). All other types of crossovers will exhibit a dip or peak through the crossover region. In this case, the behavior is a result of the phase relationships between the crossover filters and how the response sums.

You may wish to view http://www.musicanddesign.com/Power.html

[crazyhub]

Thank you guys for your thoughts especially John k! In fact I asked after having read your PR tech paper; so for what I understand is that phase by itself doesn't play in this matter but one have to consider both the type of filter and directivity patterns.
Regards