mid frequencies X-over: cap or inductor first?

[elac310]

Hello all,

I never really cared about the order of connections of the serial capacitor and the serial inductor in the X-over branch devoted to the mid frequencies in a classical 3 way system...until some time ago I had to rewire the X-overs of my self made speakers and wondering whether the cap or the inductor should be connected first (to the amplifier output), I decided to change the arrangement I had until then and connected the capacitor first and then the coil. I assumed that, theoretically, because of the well known problem of coil resonances and vibrations (I thus only use large foil-inductors), mine would appreciate to be isolated from the lowest frequencies by coming second.

Whether this view is theoretically/technically valid or not (I'm not a pro in this area), the fact is that the sound was slightly more accurate after the change. The funny thing is that when one looks at the schematic of commercial and non-commercial x-overs, the order of connections places (apparently) indifferently either the cap or the coil first and I've never read anything so far in speaker manuals or DIY magazines about this issue.

Has anyone made similar experiences that would confirm or infirm this?

Chris.

[hpolkerman]

He Elac,

Haven't tested it yet, been thinking about it as well, I've allways been told that it doesn't matter to the sound.

Now I have a test speaker with the filter on 'wires' So I can change the setup quite easily, got first the mox-resistor, then the coil and last the capacitor, i'll change all of them to see if it has any (noticable) effect (for me..).

Keep you updated in a day or two!

[AndrewT]

if the inductor is first AND there is a route after the inductor that takes some signal to return without passing the driver VC then you are wasting power.
The cap first prevents LF directly bypassing the driver, if there is an alternative route.

[elac310]

@AndrewT:
I should have mentioned that I use basic 6dB slopes on the bottom and the top / only serial components so no return path.

[hpolkerman]

Is serial mostly used is: Resistor-Cap-Coil or Cap-Resistor-Coil, coil allways at the end... In LCR order doesn't seem to matter, but I'll test it anyway!

[elac310]

So, no other practical experience to report about the sonical impact of the order of serial components cap/inductor or inductor/cap in a mid band, 6dB slopes, crossover?

[rabbitz]

From what I have seen in design books is for odd order (1st, 3rd) the inductor comes first and for even order (2nd, 4th) the cap comes first. This is consistent in all the design books I have.

Someone may be able to enlighten us on the reasons.

To answer your question it looks like the inductor first for 6dB slopes.

[crazyhub]

If your filter doesn't have component(s) // then it doesn't matter the serial inductor or cap first; if you heard some differencies I guess they were due to placebo effect, haha.