Crossover design

[Leif S]

For the record, the crossover schematic I had and showed was symmetric second-order sections, same LC values for LPF and HPF, just reoriented in the circuit to accomplish the desired filter function. That is a valid configuration. I proposed changing both caps, changing the pole and zero symmetrically with a single component value change (to two components). That will change the crossover frequency and maintain symmetry. Not the best approach, but since the OP clearly was not going to run the equations and do the simulations himself, it was an easy thing to try.

If that was not the right schematic, all bets are off.

Of course knowing more about the components (crossover and driver) and doing the full-blown analysis is better. All I was trying to do was provide something that would be close if he wanted to just swap the caps and see.

I have not listened to an old Altec system in years but IIRC driver integration was not that great to begin with compared to today's better speakers... Integrating a horn and a cone can be tricky, and it still seems like 1.35 kHz is driving the woofer pretty high, so I wonder how distortion and dispersion will be impacted.

Hi Don,
My comment wasn't directed at you and I apologize if it came across that way. I just wanted the OP to understand that changing a cap value will have an affect on the other components in the crossover. You are absolutely correct about the Altec crossovers. They are horrid lol.

 

[DonH50]

Hi Don,
My comment wasn't directed at you and I apologize if it came accross that way. You are absolutely correct about the Altec crossovers. They are horrid lol

Thanks Leif, the Internet as a conversational medium sometimes sucks. And sometimes I should leave out the word "sometimes".

Horrid, I wasn't going to go quite that far, but if the crossover fits... Different times.

 

[Leif S]

Thanks Leif, the Internet as a conversational medium sometimes sucks. And sometimes I should leave out the word "sometimes".

Horrid, I wasn't going to go quite that far, but if the crossover fits... Different times.

Yeah....over the years I have modded several Altecs for fun but did a lot of measurements before redesigning the circuits. The phase relationship between drivers was really bad. But if you bypassed their crossovers and ran processing in a biamp or triamp configuration, you could get them to sound far better. But what worked best was just redesigning a new network.

 

[Folsom]

800hz, 1.35khz, it's all past the breakup of the woofer...

 

[Leif S]

800hz, 1.35khz, it's all past the breakup of the woofer...

LMAO!!!