Help with a speaker tweak

[NewtonSheep]

it seems the speaker has two voice coils on the same former.
Use an amp, push current through the voice-coil immersed in the speakers magnetic field - the coil moves, and with it the speaker cone = sound out.

But the unconnected second voice coil attached to this cone is also being moved through the driver's magnetic field, so it works like a generator - a voltage will appear across its terminals.

Connect those terminals together with a wire link, or a resistor, and the amplifier has to do more work - because the second voice coil is now acting like a brake on the speaker cone's movement. Changing the resistor value changes the added braking. It will be none when open (unconnected), least effect for a high value resistor (little current flow) to most when you use a very low value resistor, a wire link - or a powered amplifier with no applied signal like the article! And essentially that's why the article noted such a config gave 'lean' /'taught' bass.

Any help?

Yes, very helpful. I understood that Thanks.

 

[bugbear]

Actually, it does.


Don't confuse a filter with a crossover. One is cause; the other effect. The inductor on the woofer and the capacitor on the mid are electrical filters. They effect the crossover from LF to MF. Same thing goes for the MF/HF crossover. Except that the midrange uses the mechanical / voice-coil inductance to limit its upper range and the HF uses a transformer to effect the transition.

I'm pretty sure (*) there have been several two-way speakers whose only "cross over" was a capacitor in series with the tweeter.

BugBear

(*) cannot name a single model

 

[PigletsDad]

I'm pretty sure (*) there have been several two-way speakers whose only "cross over" was a capacitor in series with the tweeter.

BugBear

(*) cannot name a single model

Epos ES14.
Various small models from Monitor Acoustics in NZ.

 

[mega lord]

I'm pretty sure (*) there have been several two-way speakers whose only "cross over" was a capacitor in series with the tweeter.

BugBear

(*) cannot name a single model

I believe the NVA cube uses only a cap on the tweeter. Mid/bass driver is upward firing.

Stu

 

[James]

Epos ES14.
Various small models from Monitor Acoustics in NZ.

ES11 too, I believe.

The point I was trying to make, but obviously failed, is that multiway loudspeaker systems have crossovers. It's how they are multiway. The crossover(s) can be effected by electrical filters (even if it's a single capacitor in series with the tweeter) or self-inductance or mechanical limitation of the diaphragm. The deleterious effect of crossovers that I think people worry about is less about insertion losses (attributed to complex filters) than how well the crossover integrates a complimentary pair of drivers.

 

[Fatmarley]

I'm pretty sure (*) there have been several two-way speakers whose only "cross over" was a capacitor in series with the tweeter.

BugBear

(*) cannot name a single model

Acoustic research AR18 and Royd Minstrel (probably lots of other Royds too)

 

[awkwardbydesign]

Martin has nailed it.

Why would you drive a car with a foot partially on the brakes?

to stretch an a analogy grossly - because you have FWD and a big turbo? had my fill of overboosted Saabs, and a judicious dab of brakes was a useful skill to get them to turn-in smartly

[size=-2] or just rotate on the spot until you learned moderation ...![/size]

Or if you have a powerful motorcycle use of the rear brake while accelerating reduces the risk of wheelies or high-siding. Look at MotoGP.