Help to Bi-Amp L300

[elshout]

I want to use an electronic crossover to bi-amp the L300's. I would like to build new crossovers to accommodate this change. I will be using a crossover schematic that member "4313B" posted several years ago. I have attached it below.

Can someone post a drawing that accomplishes the following:

"All you need is the full HF section and the low pass portion of the MF section. Protect the LE-85 with a 20 uF cap for DC and other nasties..."
This was a quote from another member, Uncle Paul.

This is what I would like to build for my project. I do not need the woofer portion and I do not need the the lower cut off section of the mid portion as this will be accomplished by the electronic crossover. I do want to keep the transition from the mid to the high and the full HF section.

Please respond if you know what portion of the attached crossover to leave out. Thanks in advance.

[4343]

No drawing, but you will have to replace the 0.30uH inductor with your 20uF protection cap and leave the rest of the components leading to the mid driver out. Simply a wire from the cap to the driver + terminal and of course the ground wire to the - terminal.

As it stands, that diagram is already setup for passive Bi-Amping, where you just parallel the inputs on a pair of amps and use the passive filters to separate the frequencies. That does lock you into the crossover frequencies that the passive has, an active crossover is usually much easier to change frequencies on.

[ivica]

I want to use an electronic crossover to bi-amp the L300's. I would like to build new crossovers to accommodate this change. I will be using a crossover schematic that member "4313B" posted several years ago. I have attached it below.

Can someone post a drawing that accomplishes the following:

"All you need is the full HF section and the low pass portion of the MF section. Protect the LE-85 with a 20 uF cap for DC and other nasties..."
This was a quote from another member, Uncle Paul.

.

Hi,
you have TO ADD to 0.30mH coil a capacitor of about 20uF OR EVEN LARGER (30uF)in 'series' with the coil.

regards
ivica

[ivica]

No drawing, but you will have to replace the 0.30uH inductor with your 20uF protection cap and leave the rest of the components leading to the mid driver out. Simply a wire from the cap to the driver + terminal and of course the ground wire to the - terminal.

.

Hi 4343,

Coil 0.30mH HAS TO remain, but mentioned cap has to be added 'in serie with the coil'.
coil is a part of the VHF/UFH crossover network

regards
ivica

[4343]

Sorry, but the UHF signal comes from the + terminal directly on this diagram, it goes straight to the 10uF cap. Break that cap free from the HF feed and you could easily passive Tri-Amp with that circuit.

[4343]

Sorry, but the UHF signal comes from the + terminal directly on this diagram, it goes straight to the 10uF cap. Break that cap free from the HF feed (and the ground of course) and you could easily passive Tri-Amp with that circuit. (If you put the LF components back that is.)

[4343]

Here with just the protection cap on the mid, I think it sounds better with the resistor, you can try it with and without and see what you think.

[elshout]

Hey 4343, thanks for the replies. I want to make sure I understand.

In your last diagram, the one above, I see the ultra high frequency circuit stays the same. No problem. My question is, in the new circuit above, does this only protect the Mid driver, or does this also remove the upper high frequency from the Mid driver. I want to make sure it does both, remove the ultra high frequency and protect the driver. The low frequency will be removed by the active crossover so I do understand why most of the circuit was removed.

Thanks

[just4kinks]

The inductor is part of the low-pass filter for the mid. You want to keep it unless you tri-amp. The last schematic removes the low-pass filter from the mid driver.

elshout, the first schematic you posted is pretty much what you want. You can put the 20uF cap in series with the mid+, or in between the 5 ohm resistor and the L-pad.

Hey... why is the 2405 polarity inverted?