Bass drivers which cleanly roll-off without a low pass filter.

[theophile]

As a life long music-lover and hi-fi user for over 30 years one of the paths to refining the amp/speaker interface - the elimination of the passive network which interposes between the amp and the driver - has been a touchstone for me.I have used an active crossover with absolutely no amp/speaker interposing crossover for the past 8 or so years.

I have in the past used a small speaker(the original AR 18)which used an 8 inch paper cone driver that had absolutely no low-pass crossover element.In fact the 8 inch driver got the entire frequenct spectrum via the rear terminals.The only crossover element was one capacitor for the tweeter at 2KHz.

I philosophically like the idea of an arrangement which obliviates the need for an electronic filter by virtue of the natural characteristics of the driver(caused by materials,design or any other means).

Are there such beasts?

I know this is very open-ended,not the least because I haven't laid-out any particular roll-off frequency I'd like to commence from,what efficiency I'd like to the utilising,minimum or maximum cabinet sizes that I would consider,how much I'm prepared to spend (etc).If I were to be specific I'd be looking for a driver having 500Hz roll-off equiv to 12dB per octave with efficency of 98 dB/W/M.

Is there anything out there which has characteristics such as those?

[CLS]

4th order band pass?

[theophile]

Originally Posted by CLS

4th order band pass?

Mate It's sometimes around the 14th order of drinks that I'd start hoping the band will pass on doing another set.

[Helmuth]

Originally Posted by theophile

Are there such beasts?

I know this is very open-ended,not the least because I haven't laid-out any particular roll-off frequency I'd like to commence from,what efficiency I'd like to the utilising,minimum or maximum cabinet sizes that I would consider,how much I'm prepared to spend (etc).If I were to be specific I'd be looking for a driver having 500Hz roll-off equiv to 12dB per octave with efficency of 98 dB/W/M.

Is there anything out there which has characteristics such as those?

May be a voice coil of 2,6mH without copper ring in motor assembly can cause such roll off far i can see they all done their best to get extended midrange.

You shout make a front loaded horn like this.
Back Loaded Horns

[jwmbro]

I agree with Helmut. A front-loaded horn functions as a natural accoustical lowpass.