Series crossover-can i use l-pad on tweeter

[Akrambash]

I have just tested this lc audio series two way crossover network on my speakers and they sound fairly decent and not shabby like ar-sxo crossover. I would like to know if i can add an l-pad to the tweeters or rather if l-pads can be used with serial crossovers. secondly i want to know if impedance correction circuits or zobel can be added to a serial network

[PeteMcK]

yes & yes

[rabbitz]

If you mean an L-pad using a series resistor and parallel resistor for the tweeter then it works fine but a variable L-pad can have some weird effects. I've never been able to get the latter to work correctly in a series crossover but used a range of parallel resistors that could be externally switched for SPL variations.

Zobels work fine but the complete filter has to be designed to suit. A zobel on the woofer also effects the tweeter roll off in a series xo and in the extreme, will make the tweeter roll off plateau so will have little reduction at Fs. It has to be designed as one circuit as you just can't add a zobel to an existing filter. Model one and you'll see what I mean as every component change effects both the tweeter and woofer.

There's nothing wrong with a well designed AR series crossover and in fact most of my speakers use them. They just have to be designed like any other xo to suit the drivers and design. If you use the info on the AR site, there's a low chance of it working correctly. Use it only as a rough guide.

[Akrambash]

Since I'm using component values described in the LC audio website...It is not possible for me to know the actual crossover frequency. Is there any way to know(may be a calculation) the crossover frequency...I'm familiar with parallel crossover calculations, but illiterate about series networks..but i love the way these networks sound

[PeteMcK]

Series vs. Parallel Crossover Networks

[Akrambash]

I have always struggled designing series crossover because i don't know how to calculate the component value to cutoff a particular frequency.....where as in a parallel network you can easily calculate the capacitor or inductor value for the desired frequency...........
I know that series network work differently but i have found no resource to understand this...what determines the component value for a particular frequency in a first order series crossover...
Kindly educate me on this..Thanks a lot

[PeteMcK]

the equations are in the linked article above

[sreten]

Hi,

If you up the 2R0 resistor in value you end up with a parallel 1st order c/o.

If you short it you end up with a series c/o, 1st order bass, 2nd order treble.

So its some kind of hybrid, not the easiest to analyse.

rgds, sreten.

[GloBug]

Oh I-pad, not iPad, lol

[AllenB]

Actually GloBug, it's L pad, due to the way a series and parallel resistor are placed like an 'L' (or more like a '7')

Anyway, a series crossover isn't a great place for a first timer to be. With a basic series crossover, anything you do to bring the impedances closer to flat and equal between each driver (and this means L-pads and zobel networks), the closer the filter itself comes to working as it should. Still though, this doesn't mean that's exactly what each driver happens to need.