# modifying a passive x-over to be bi-amp/bi-wire capable?



## tophatjimmy (Dec 16, 2005)

Anyone know if this can be done or want to assist in figuring it out?

I can't tame this tweeter down enough using the passive as-is and running active isn't an option for me in this install. Components are Hertz HSK 165's.

I can get some pics of the xovers in question if anyone feels like helping tackle this.


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## MarkZ (Dec 5, 2005)

Yup, it can be done for most crossovers (all "regular" ones, at least). Each branch of the crossover receives the same input signal. You need to separate them. Basically means lifting one of the inputs from the board and wiring it to a new terminal. Do the same with the minus leg. A multimeter will tell you all you need to know. Figure out which components show continuity with the + and - input terminals.


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## MarkZ (Dec 5, 2005)

And yes, a picture would be a helpful start. Preferably top and bottom of the board.


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## Oliver (Jun 25, 2007)

buy new tweeters


> Allan74
> DIYMA freshman
> 
> Join Date: Jun 2010
> ...


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## Allan74 (Jun 17, 2010)

Oliver said:


> buy new tweeters


Yup. My ML28's are in transit as we speak.

Even though I thought I had it covered by running my HT25's on a seperate Amp, Active (_near supertweeter x-over point @ [email protected]/oct_), deidicated EQ channels and with much less power - I still decided to replace in advance due to what I experienced before.

HV165's love power. HT25's do not. For Hertz's most popular retail kit, in 2006 they sure did a piss-poor job of driver matching.

At medium volume with moderate power, the 2006/08 HSK-165 kit's HT25's sing. Anything higher (from what I found) simply makes them SCREAM.....5-6khz was almost painful.


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## Volenti (Feb 17, 2010)

All he needs is an L-pad, no need to mess around in the x-over unless you really want to.


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## tophatjimmy (Dec 16, 2005)

Thanks for the responses. After studying the traces on the boards, I went ahead and modded my existing xovers. I found that isolating the woofer circuit was the easiest since it was just a single cap and coil.

So far it works just as I was hoping.

I may eventually swap tweeters as well. I have a set of Focal TN-52's that I loved in my previous car.


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## MarkZ (Dec 5, 2005)

good job!


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## drumcrusher (May 4, 2008)

I don't suppose I could get a photo of your work could I? I've been thinking about doing this to my hertz too. I need to get some amp repairs done before I can go active...


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