LX-mini Crossover Article

Dear Mr. Pass,

If you could indeed provide the board for the Toshibas / Linear Systems, that would be superb! I built the smaller size SLOB with Coral Beta 8s and Eminence Beta 15As, thus I want to build the b5 as I'll have to tame the rising response in the treble (ca 10-14 kHz) and use the equalization for bass boost.

Thank you so much,



2010-11-06 7:07 pm
I might be being completely daft but the LX-mini XO is only 2-way. The chassis looks like it is 3 way ( which is what I am after ) - does this mean there is an imminent release planned for a 3-way design? I know NP had mentioned a 3-way in the original article.

just curious..dB
Also the chassis has balanced in and out.
Will that be supported by current PCBs?
So to get a balanced crossover you would order two full kits and chassis then you just plug them in. The 2 channels in each box combine into a balanced channel,- no switches, jumpers etc.

We added the 3rd pair of RCAs so you if later you want you can add one of the big woofer options to the LXmini
Last edited:


2006-08-06 11:05 pm
Small of topic but related to j113.
Any body tested j113 to brake down voltage?
I tried to kill one with voltage , but I dont have enough voltage.

With 80Vdc drain -source voltage and 3mA current, they steel working.

Test setup 1kohm base stoper to ground and 330 ohm Rs.
Hi Nelson, I have a pair of Altec 604-8Gs in homemade 620cabs. Have used different crossovers on them. Best crossover was an autoformer crossover that was later modified for my Altec A5s and currently used there ( great result ). It could be fun to do an active xover for the 604s ( and an excuse to build more amps ;) ). Would it make sense to use the lx-mini kit as a base or do you have plans for realeasing a more general 2way active xover kit later?

Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
Would it make sense to use the lx-mini kit as a base or do you have plans for releasing a more general 2way active xover kit later?

There are plans for a more general crossover.

The LXmini crossover can be stuffed for a variety of loudspeakers.

You have the board and existing schematic, and I have posted a
MicroCap sim file:

www.firstwatt.com/sims/LX_MINI_V1R0.CIR for you to play with.

You can download the Windows demo version of MicroCap from:

Spectrum Software - Micro-Cap 12. Analog simulation, mixed mode simulation, and digital simulation software. SPICE and PSpice(R) compatible circuit simulator.

and alter the values to see the resulting curves.

After installing MicroCap demo, you click on the file and it launches you
into the screen showing the schematic. On the top bar, click on
Analysis, then AC, then Run, and see the result. You can edit the values
right on the screen, and after a little practice you can be doing this on
your own.

Note that the active elements in this sim are VCVS, voltage controlled
voltage sources whose value (gain) is set up as a buffer.

Thank you for all. My kit is on its way. Don't have Lxmini speakers but maybe in the future.

The kit is needed for a OB setup with Mark audio 10.3 and Eminence Beta 15".

I need to change the values, however im a complete noob at this. Can you help? What do i have to do first? I think i must decide at what frequency i need to crossover, right?