Low freq. from small drivers? Is it possible


Can you get really low freq. (lets say 30 and down) from a small driver (~6 inch? What is the relationship between driver size and frequency? Most speakers today have went away from a large base driver (10 inches or more). Have we really come that far or is it really a compermize?

Any recomendations for smaller floor standers with good bass?

Thanks,

Dr. Ken
drken
El: Series crossovers consist of the opposite components one would use in a parallel crossover.

While "common" crossovers are called "parallel" designs, they really are closer to a series circuit by their very nature. Some newer speakers ( and old ones like Fried and Koss ) use what is called a "series" crossover, which is really like a parallel circuit. You can see a diagram of a basic "series" crossover here at Karl's website. The terminology is quite confusing and i can understand why this baffles people.

As a side note, i was doing a search and ran across Clement Perry's comments about Karl's speakers. You can read it by clicking on the link to Stereotimes CES coverage. Sean
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Sean:
Series crossovers consist of the opposite components one would use in a parallel crossover
I think that's what El was asking about: how come the woofs are looking, so to speak, at an inductor rather than a cap...
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