Designing a crossover

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I was wondering when designing a crossover the passive network load for each driver .Do you leave the network load at 8ohms or for each driver do you use the RE that you have measured for each driver?
Also when doing the bandpass how do you determine the crossover points in relation to the woofer and tweeter crossover points ?
I am also wonder if anyone can point me to a tutorial on the right way to measure loudspeaker spl.
Maybe someone should do one so when someone new decideds to do it it is there in the wiki for it .

 

[Ron E]

I was wondering when designing a crossover the passive network load for each driver .Do you leave the network load at 8ohms or for each driver do you use the RE that you have measured for each driver?

The best is to use the measured impedance and phase that varies with frequency.

Also when doing the bandpass how do you determine the crossover points in relation to the woofer and tweeter crossover points ?

That is a difficult question, and I would begin an answer by saying that one should not try to design a 3-way without optimization software and measurements of both SPL/phase and impedance/phase. Success is possible, but not probable without the right tools.

I am also wonder if anyone can point me to a tutorial on the right way to measure loudspeaker spl.
Maybe someone should do one so when someone new decideds to do it it is there in the wiki for it .

There is a program called Speaker Workshop, and there is an unofficial manual that goes through the measurement steps.

Other than that there are a few good books on loudspeaker design, such as Testing Loudspeakers by Joseph D'Appolito.

 

[PeteMcK]

some of this may be useful:

Getting started in Crossover Design

The basics (You've got to understand the rules before you can break them
http://sound.westhost.com/lr-passive.htm
choosing xover point:
http://www.speakerbuilder.net/web_files/Articles/xover article/xpointmain.htm
Baffle Step Compensation: http://sound.westhost.com/bafflestep.htm

Getting it done:
Jay has a page on designing xovers using manufacturers specs without measuring:
http://www.geocities.com/woove99/Spkrbldg/DesigningXO.htm

Calculators:
http://ccs.exl.info/calc_cr.html#second
http://www.sengpielaudio.com/calculator-Lpad.htm

Measurement freeware:
Synrta - http://libinst.com/SynRTA.htm
ARTA http://www.fesb.hr/~mateljan/arta/download.htm
ARTA Jig - http://zobsky.blogspot.com/2008/01/simple-loudspeaker-measurement-jig-for.html

Examples from the designs of others can be quite instructive:
http://www.zaphaudio.com/
http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm
http://www.rjbaudio.com/projects.html
http://www.humblehomemadehifi.com/