Driver TS parameters
- Vas in liter (l)
- Qts
- Fs in Hz
- Vd in liter (l)
- Becareful, use Qts'=1.1*Qts for taking into account the resistances of the circuit
(amplifier, cables, low pass filter inductance)
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Loudspeaker parameters
- S=5.7
- Ka=0.39
- Qb=7
- Those values give the flattest response.
- You can change it, use mainly S and Ka.
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Enclosure volume Vb
- Resonance frequency, Fb(Hz)=Ka*Fs/Qts
- Enclosure volume, Vb(l)=S*Qts^2*Vas
Port Calculation Sp, Lp
- Minimum area, Spmin(cm2)=8*Fb*Vd
- Maximum lenght, Lpmax(cm)=34000/12/Fb
- Let's calculate Kp=1000*(170/PI/Fb)^2/Vb
- If you know your port area Sp(cm2)
- Ap=Sqr(Sp/PI/10000)
- Lp(cm)=Sp*(Kp-0.465/Ap)/100
- If you know your port lenght Lp(cm)
- B=PI*0.465^2+2*Kp*Lp/100
- Sp(cm2)=2*Lp^2/(B-Sqr(B^2-4*(Kp*Lp/100)^2))
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Frequency response
- A0=(Fb*Fs)^2/Fs^4
- A1=(Fb*Fs^2/Qb+Fs^2*Fs/Qts)/Fs^3
- A2=(VAS*Fs^2/Vb+Fs^2+Fb^2+Fb*Fs/Qb/Qts)/Fs^2
- A3=(Fs/Qts+Fb/Qb)/Fs
- Let's write Fr=F/Fs where F is the frequency of interrest
- G(Fr)=20*log10(Fr^4/Sqr((Fr^4-Fr^2*A2+A0)^2+(Fr*A1-Fr^3*A3)^2))
- G(Fr) in dB
- You can extract the -3dB frenquency from G(Fr) table
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