2 way speakers with mechanical crossover

[Hiten]

Hi all
I had seen some 2 way speakers (Not sure but AR I think) where the woofer was said to be mechanically constructed in such a way that it damps (attenuates) high frequencies and this served as a low pass filter. The tweeter had a capacitor and resistor.

So my question is. Can a mechanical crossovered 2 way speakers be made ? I guess this would not be high fidelity but would be interesting. We can use 2 or 3 inch driver to produce high frequencies. it would be sealed from behind the cone. (see below picture) So cone movement is highly restricted and serves as high pass filter. Or by any other mechanical means which attenuates low frequencies.
Is it Possible ?

Thanks and regards

 

[ewollowe]

Epos have several models not using crossovers on their woofers. I'd imagine there are more companies doing this too.

You can mount a driver "basket out" to restrict it's high frequency output.

 

[Sonce]

Can a mechanical crossovered 2 way speakers be made ? I guess this would not be high fidelity but would be interesting. We can use 2 or 3 inch driver to produce high frequencies. it would be sealed from behind the cone. (see below picture) So cone movement is highly restricted and serves as high pass filter. Or by any other mechanical means which attenuates low frequencies.
Is it Possible ?

May be possible, but power handling will be extremely low because there will be no electrical high-pass filter for the 2 or 3 inch tweeter. Another problem is matching the woofer's mechanical low-pass frequency to the tweeter's mechanical high-pass frequency to be the same.
You may use 2 or 3 inch "fullrange" driver (the power handling will be good!) in a small closed box, but it's "mechanical" high-pass frequency point will be rather low, so there will be a problem to find a woofer with such a low "mechanical" low-pass frequency. In this case bandpass woofer box will do the trick.

 

[Sonce]

Epos have several models not using crossovers on their woofers. I'd imagine there are more companies doing this too.

Mordaunt Short in some older models, too.
They all use electrical high-pass filter for the tweeter, which is not the OP want.

 

[ewollowe]

Mordaunt Short in some older models, too.
They all use electrical high-pass filter for the tweeter, which is not the OP want.

OP is interested in 2 way crossoverless speakers, I was just pointing him towards other speakers with some similar characteristics to help get the ball rolling.
I never claimed to be offering him a complete solution.

 

[Hiten]

Thanks. So I think main obstacles would be frequency matching of both drivers and mechanical high pass filter for tweeter or small cone drivers is not possible.

Since audio transformers are said to be band limited can they be used ? One can design specific transformer for specific frequency bands. Like windings in such a way that it will deliberately have some capacitance and attenuate low frequencies. Pardon for noob queries.
Regards.

 

[Sonce]

Audio transformers are not band limited in that way. So stick with the fullrange-in-a-closed-box plus bandpass-woofer solution.

 

[eriksquires]

Apparently so. Check out the full range drivers at Madisound. Fostex makes some very affordable drivers like this.

Best,

Erik

Hi all
I had seen some 2 way speakers (Not sure but AR I think) where the woofer was said to be mechanically constructed in such a way that it damps (attenuates) high frequencies and this served as a low pass filter. The tweeter had a capacitor and resistor.

So my question is. Can a mechanical crossovered 2 way speakers be made ? I guess this would not be high fidelity but would be interesting. We can use 2 or 3 inch driver to produce high frequencies. it would be sealed from behind the cone. (see below picture) So cone movement is highly restricted and serves as high pass filter. Or by any other mechanical means which attenuates low frequencies.
Is it Possible ?

Thanks and regards

 

[sreten]

Hi,

All tweeters by default are mechanically hi passed.
All tweeters by default will blow fed a full range signal.

Shedloads of cheap speakers are built with no x/o
on the bassmid unit and a single capacitor on the
tweeter to prevent low frequency power blowing it.

rgds, sreten.

 

[planet10]

It could be done, but getting the speakers to match is problematic, and i’d want to use a good midTweeter (ie small FR) up top. A sealed alignment creates a 2nd order HiPass, but they still get all the LF crap. Putting even a 1st order filter helps this driver in its passband by releiving the driver in the bass. Note that the mechnical XO point is going to be fairly low. The 2 problems presented are often dealt with by simply hi-passing the tweeter with a single cap at the point where the midWoofer starts rolling off.

By the way, those alnico National/Panasonic tweeters are quite decent, but i would not use them without a high-pass.

dave

PS: a fullrange with a whizzer cone is a driver with a mechanical crossover built-in.

 

[Hiten]

Thanks gentlemen.
I know laws of physics can not be bypassed. I read some drivers have fan attached to it. A highly rugged and highly efficient small driver which can handle power and dissipate generated heat can be useful.
Regards.