Cross over design

[JDeV]

I would like to build a small bookshelf speaker using the following components.

Tweeter: Vifa D25AG-05-06
Mid/Bass: Vifa P13MH-00-08
Cross over: Ar SXO (generic series)

Can some 1 help me to design the values for this crossover, since the drivers are 6ohm and 8ohm respectively.

Herer are the specs:
D25AG-05-06

Nominal impedance [ohm] 6
Voice coil resistance [ohm] 4.6
Nominal power [W] 100 Aluminium Alloy
Short term max power [W] - diaphragm
Long term max power [W] -
Operating power [W] 4 Magnetic Fluid
Sensitivity [dB] 91
Frequency range [kHz] 2.5-35 High Loss Suspension
Free air resonance [Hz] 1500
Voice coil diameter [mm] 25 Piston movement
Voice coil height [mm] 1.6 to above 20 kHz
Air gap height [mm] 2
Voice coil inductance [mH] - High precision Phase
Eff. diaphragm Area [cm²] 7.1 Shield
Moving mass [g] 0.3
Magnet weight [g]/[oz] 240/8.5
Force factor [Bl] 3.5
VAS [l] -
Qms -
Qes -
Qts -
--------------------------------------------------------------------------------
P13MH-00-08

Nominal impedance [ohm] 8
Voice coil resistance [ohm] 5.8
Nominal power [W] 40/90 Low resonance
Short term max power [W] -
Long term max power [W] - Very low distortion
Operating power [W] 4.5
Sensitivity [dB] 89.5 Optimized off axis
Frequency range [kHz] 0.2-6 response
Free air resonance [Hz] 60
Voice coil diameter [mm] 25 Neutral midrange
Voice coil height [mm] 8 reproduction
Air gap height [mm] 6
Voice coil inductance [mH] - Mineral filled polycone
Eff. diaphragm Area [cm²] 86
Moving mass [g] 6.5 Vented through V.C.
Magnet weight [g]/[oz] 415/14.6 former and pole piece
Force factor [Bl] 5.8
VAS [l] -
Qms -
Qes -
Qts -
--------------------------------------------------------------------------------

 

[JDeV]

AR SXo

Here are cross over:
http://www.acoustic-reality.com/ar-sxo.htm

Thanx for all help.

 

[JDeV]

Inductor core?

Another question, I noticed on my existing speaker's crossovers, that there are inductors with air cores and ferrite cores, why would this be? Aint it a bad idea to use ferrite cores in a crossover inductor? (These speakers are Monitor Audio and Mission. )

 

[kelticwizard]

Re: Inductor core?

Another question, I noticed on my existing speaker's crossovers, that there are inductors with air cores and ferrite cores, why would this be? Aint it a bad idea to use ferrite cores in a crossover inductor? (These speakers are Monitor Audio and Mission. )

Generally, ferrite cores are used when the cost of an air core inductor would become prohibitive for the speaker's price. The more wire muct be wound, the less the gauge must be to keep DC resistance down.

Lesser gauge wire costs more because it takes more copper to make it thicker.

Ferrite cores allow you to wind less wire for the same inductance as air cores. It all comes down to the judgment of higher distortion from the ferrite core becoming a lesser evil than the high resistance of the air core-or the high cost of increasing the wire thickness to keep the air core DC resisitance down.

 

[kelticwizard]

This DIYAudio member here, Andy Graddon, has a series crossover spreadsheet, plus lots of other series crossovber links. Try filling in the values of the spreadsheet and see how close it comes to the series crossover of Acoustic Reality.

Haven't tried the spreadsheet, not interested in series crossovers, (yet, anyway). But other members here have tried it and found it okay.

http://home.iprimus.com.au/gradds/

Good luck!

 

[JDeV]

Thanx alot Mr.Keltic , much appreciated.