Newbie alert - First project, two way tower

[phokas]

Hi all

I have some units ready for my first project, a budget sealed two way tower.

They are Vifa BC18SG59 6-1/2" 8ohm

*Power handling: 80 watts RMS/160 watts max
*VCdia: 1"
*Le: 0.81 mH
*Impedance: 8 ohms
*Re: 5.05 ohms
*Frequency response: 53-4,000 Hz
*Fs: 33 Hz
*SPL: 89 dB 1W/1m
*Vas: 0.85 cu. ft.
*Qms: 3.35
*Qes: 0.78
*Qts: 0.63
*Xmax: 3.5 mm

Tweeters Vifa BC25SC06 4ohm
Resonance Frequency fs 1350 Hz
Mechanical Q factor Qms 2.37
Electrical Q factor Qes 2.3
Total Q factor Qts 1.26
Force factor Bl 1.7 Tm
Mechanical resistance Rms -- Kg/s
Moving mass Mms 0.35 g
Suspension compliance Cms 0.27 mm/N
Effective cone diameter D -- cm
Effective piston area Sd 6.8 cm2
Equivalent volume Vas -- ltrs
Sensitivity (2.83V/1m) 96 dB


I plumbed the data from the woofers into winisd but need a little advice on crossovers. I understand from reading on here that to achieve accurate crossovers requires measuring equipment and expensive software.

However given the tight budget and this being my first project can anyone give advice on trying different methods...maybe purchasing several components to try and tweak by ear?

Using online calculators to work out a 2nd order butterworth at 3000hz I came up with these:

High Pass
C1 9.375uf
L1 0.300133 mH

Low Pass
C1 4.6875uf
L2 0.600266mH

Is anything else needed for a simple crossover, I noticed the tweeters are more sensitive than the woofers 96/89

Thanks in advance

[mikje]

I would say at a minimum, you'll need to add an L-Pad to bring the tweeter sensitivity to within 3dB of the woofer, and you'll need to see if there are any peaks that need tamed?
How did you decide on the crossover point?
Here is a link to some free software for crossover design jbagby
If you check out the Parts Express forum, you'll find a lot of advice and possibly some help on the right crossover for your project.
Have fun with it...
Mike

[phokas]

Thanks mikje I will take a look at the software and do some searches about L-Pad's

I read that the tweeter fs should be at least half the crossover point.