Low freq. from small drivers? Is it possible

Yep Gregm.

In a series crossover you first put the woofer and tweeter in series. That would, of course, pass all frequencies through both drivers, briefly until the tweeter burned out. To avoid this you put an inductor across (in parallel with) the tweeter, so that LF signal bypasses the tweeter. Similarly, a capacitor across the woofer keeps HF out of that driver. The value, mH, of the inductor, together with the inductance of the driver determines the high pass frequency of the tweeter.

In summary, the inductor relates to the tweeter, not the woofer.

Perhaps the terminology just got mixed up, but, I wonder...

The terms "series" and "parallel" describe the basic topology of the circuit, and refer to the connection arrangement of the DRIVERS. Look at the diagram link from Sean above for the first-order "series", and note the difference in driver connection compared to a "parallel".

But regardless of whether it's "series" or "parallel", the main inductor is still in series with the woofer, and the main capacitor is still in series with the tweeter. If you don't understand how this can be, it's time to do some homework. I'll give you a hint to get you started: Always think about where the CURRENT flows at a given frequency, because that's what makes the driver move. It follows the path of least resistance, just like water.

Best Regards,
Karl Schuemann
AudioMachina

Karls...Having messed around with crossovers for more than 40 years, I don't need your schematic to comprehend a series network.

Let me ask you...which driver's crossover frequency does the inductor determine? Shouldn't we call the inductor by the same name as the driver it serves?

The way I regard a series crossover is as a series connection of two elements...(1) Tweeter/Inductor parallel pair and (2) Woofer/Capacitor parallel pair.

(And, to Sean's point, a "parallel" crossover is a parallel connection of two series-connected elements).

Makes sense to me, but you evidently have some other way of looking at it. There is more than one way to skin a cat, which we can perhaps agree is a good idea.

Eldartford,

If you want to learn a new way of thinking, perhaps you would do well to listen to what I said, and not continue to insist on thinking about things the way you have for 40 years. I will give you another hint, and perhaps this time you will listen and actually do some thinking.

In a simple two-way parallel crossover, there are two possible paths which the current may follow. At low frequencies, it follows primarily one path (the one through the woofer), and at high frequencies, it follows primarily the other path (the one through the tweeter). In the crossover region, it goes some through one and some through the other.

In a simple two-way series crossover (such as that shown on our website), there are four possible paths which the current may follow. I leave it up to you to (1) figure out what those four paths are, (2) figure out which two paths it primarily follows, one at low frequencies and one at high frequencies, and (3) compare those two paths to the two paths in the parallel case.

Hopefully, after you have done so, you will begin to understand what I was trying to tell you. The analogy between electrons and water is an old one, but still invaluable.

As far as your question of "which" element goes with "which" driver in a series crossover, the short answer is: they don't. Both elements affect both drivers, as a cursory glance at the circuit will tell you.

Karl Schuemann
AudioMachina

The current trend towards 6" drivers (or smaller) has been going on for quite some time...and i do think it is a good trade in relation to the large 10" drivers and cabinets of yesteryear...the gain in transparency and involvement of small two-ways at the expense of deep bass is a fair trade in my estimation...small speakers are capable of very good bass extension...especially in small rooms...