aligning drivers

[mrkramer]

I was thinking about methods to align the acoustic centers of drivers. I'm not entirely sure that I will get any closer to time or phase alignment but all in all it seems like a good idea. So I was wondering what the merits of a couple different approaches might be.

-Angled baffles.
Seems easy enough to make.

-Stepped baffles.
looks funny to me. Seems that the shelf would cause diffraction.

-Waveguides.
Seems like it might be a great choice but might cause a lot of other issues. Also to get the mouth large enough for a given xover that the ctc distance would have to be pretty big too. Problem or not?

-nothing.
Too much hassle for too little benefit.

Would really love to hear peoples thoughts and experiences on this.

MrKramer

[Conrad Hoffman]

Stepped baffles work fine for me. I've also built angled cabinets that worked well. IMHO calculations and prediction might be a little shaky, but it's a great tuning tool and I'd never consider just mounting drivers on a flat surface and hoping for the best.

[trusound]

I build all mine using steps or angles... but I try to do steps first.. I find that the T/A and coherency is better then just angling the baffle or angling the listening position via stands..

time and phase is a lost art IMO

[abefroeman]

Active Crossovers

[David Gatti]

My previous design was sloped, but I think my next will be stepped.
It's true that a stepped baffle will cause some diffraction, but often the driver cone itself is a greater source of diffraction.

[454Casull]

Art Ludwig does it with angled steps.

http://www.silcom.com/~aludwig/Louds...Time_alignment

[trusound]

ahh.. a man after my heart... I guess this is the car audio side of me speaking... but full control over xover point,slope,T/A and eq makes me happy

Originally posted by abefroeman
Active Crossovers

[trusound]

here is what I am building now...


sorry I draw like a retarded gang banger

[The golden mean]

Sorry, while a sphere as the external image of an enclosure could be a good thing when it comes to spread diffaction with regards to frequency, a sphere or a tube as the internal shape of an enclosure isn´t the best shape because standing waves will be gathered at certain frequences. Having visited conserts in "the Globe" in Stockholm and the lectue-theatre that has a dome as aprominent part to it.

About the time alignment the problem is that time delays because of a crossover e.g. is not cured by a "step function" as it is a continuous rather than a descrete function.

[454Casull]

Originally posted by The golden mean
Sorry, while a sphere as the external image of an enclosure could be a good thing when it comes to spread diffaction with regards to frequency, a sphere or a tube as the internal shape of an enclosure isn´t the best shape because standing waves will be gathered at certain frequences. Having visited conserts in "the Globe" in Stockholm and the lectue-theatre that has a dome as aprominent part to it.

About the time alignment the problem is that time delays because of a crossover e.g. is not cured by a "step function" as it is a continuous rather than a descrete function.

If you stuff a long tube properly, you can kill most or all of the midrange reflections.

I think people are just talking about physical offsets, not those introduced by crossovers.