2way lowvolume speakers alchemy

orfeus

Member
2008-01-24 8:41 am
I designed a 2 way BR system of volume restrictions (maximum 10 liters).use Vifa 14 plw, visaton dsm 25 ffl titanium.
i have calculate my speakers filters from impedance diagramm,RL,Le, 1w-1m db and infinite distane db (for reference). I also used the composite impedance of mechanical properties and the divided impedance since the systems (woofer-tweeter are parallell, with different Ztotal, for every frequency. In result i must turn the tweeter 25 degrees off axis from woofer,use a 0.220 microF capacitor for tweeter and at least a 2200microF for woofer phase correction. My absolute db variation is about 3db in 100hz-20khz. Anyone has any idea of the result or mistakes?
It might be a failure? Thank you.
 
"I also used the composite impedance of mechanical properties and the divided impedance "

Orpheus, you don't need to do this;
Use the impedance of the woofer at the crossover frequency for calculating the woofer part of the crossover, and the tweeter impedance at the crossover frequency for calculating the tweeter side of the crossover.
 

orfeus

Member
2008-01-24 8:41 am
Let me be more detailed.

We have some mechanical and some electrical resistances in a woofer. The impedance diagramm of a woofer gives the composite resistance. I did calculate the electrical resistance of the Rl and Le parameters for a frequancy spectrum. Then i realized that mechanical resistance is somewhat additive to the electrical resistance and extract the mean value. From the sensitivity diagramm, i calculated the db in contrast with impedance. Next i suppose i put the 2 drivers in parallel and a virtual 1st order crossover with a trial to make zero the coil value. To flat the response on high freqs i need a 40 degrees turn to the tweeter and a 15 degrees turn to the woofer, so i turned eachother about 25 degrees and decide to turn 15 degrees the speaker from the listener axis. So, the result on sensitivity was a 8db peak in about 1.5k and a constant 5db higher state on tweeter above 2k. The solution was to put a .220microF in series with tweeter. The 2200micoF of woofer has been put just for phase correction. As you may realize there is no crossover.Since i havn't built it yet my question is if there are errors that i didn't calculate. If there is anyone who has experience with crossoverless systems, he may help.
 
Ok, I think I understand what you're doing now.
I think your main problem is going to be stopping the low frequencies causing distortion in the tweeter.
But it's simple enough to impliment and try at a low level.
It would also be interesting to try the woofer without the 2200uF and see if you can hear a difference...