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
Karl: My experience with even very high grade "passive parts" placed smack dab between the amp and drivers is that they drastically reduce sound quality. One can use even a lower grade electronic crossover and get better results than if one used very simple passive crossovers of the highest quality. At least that's been my experience.

My Brother argued with me about this for quite some time. That is, until i gave him an old electronic crossover that i hadn't used in years and he tried it out. Pulling even a single cap from his tweeters made a HUGE difference in terms of sonics. Why one can get away with running a MUCH more complex circuit at line level without near as much sonic degradation is beyond me, but i'm guessing it has something to do with the current levels involved.

After studying the circuit lay-out of a series crossover, i've often wondered how much more "low frequency leakage" there is into the tweeter as compared to a standard 1st order "parallel" crossover? I've also wondered about the differences in power handling between the two. Have you ever compared the two with identical designs? Sean
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PS... Thanks again for your taking the time to clarify your comments and respond to further comments / questions.
Sean,

I'm aware of the advantages of actives, but again it becomes an issue of the overall design compromise. As few people would be interested in a $15k/pr monitor, only a tiny fraction of them would even take a glance if it required biamping. Besides, using really high quality parts makes a huge difference, and keeping it simple helps perhaps even more.

The tweeter power handling (from LF leakage) in a series crossover is a function of the DCR of the woofer inductor. The tweeter attenuation "shelves" at some point, and the lower the DCR, the lower that point is.

The power handling in our case isn't even close to being an issue. The inductor is small with very low DCR, the crossover point is fairly high, the tweeter is padded down, and on top of all that, the response is designed to fall like a brick below the tweeter resonance, which is more than two octaves below the crossover point. So in this particular case, it is more than bombproof. But that isn't always the case.

Best Regards,
Karl Schuemann
AudioMachina
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...