Silly question...why not dual voice coils?

[Darth Tater]

In the car audio and hi-fi speaker world, dual voice coil speakers are the norm. For instance, a dual 8 ohm voice coil speaker can be wired as 4 ohm, 8 ohm, or 16 ohm all in that single speaker.

Why not in guitar speakers? Is it because the extra voice coil would weigh too much? I know the goal in guitar speakers is to get as light as possible, so I'm guessing that's why. Thoughts?

[rodie]

well, think about which speakers are dvc. subwoofers aren't known for their dynamics, but are definitely needing heavy heat dissipation...speakers that handle dynamics and transients don't come dvc...the motor structure is way too heavy to be responsive, and they don't create high heat levels...

also, overhead is lower if the speaker can be tailored to suit the application, i.e. multi ohm taps mean you only have to sell one of each size in the line...

[gulliver]

I think it's because most guitar amps have the ohms selector switch based on the taps in the transformer ... we do it with the amps, where it's easier to reach.

:beer

[Darth Tater]

I think it's because most guitar amps have the ohms selector switch based on the taps in the transformer ... we do it with the amps, where it's easier to reach.

:beer

Over my 20 years of amp buying, I've only had one amp that had multiple impedance outputs...a Soldano Decatone. And I don't think I've ever seen a Fender amp with a 4/8/16 ohm output and that brand seems to be somewhat popular.

So I don't think that's it. I'd like to hear from a speaker designer on this. Speaker design has just always fascinated me and I'd like to know why a guitar speaker can't have dual voice coils. I still say it's the weight.

I'm not sure about the transient/dynamics thing either...subwoofers handle just as much transients and dynamics (if not more) than anything. I can't imagine anything with more transients than a double bass drum.

[~Abstract~]

In the car audio and hi-fi speaker world, dual voice coil speakers are the norm. For instance, a dual 8 ohm voice coil speaker can be wired as 4 ohm, 8 ohm, or 16 ohm all in that single speaker.



Can you explain how to wire dual 8ohm loads for an 8ohm final load?

If so, you're better than I.

[Darth Tater]

Can you explain how to wire dual 8ohm loads for an 8ohm final load?

If so, you're better than I.

You just use 1 of the 8 ohm coils. You don't have to use both, unless something changed since the last time I wired a DVC speaker (which has been a while!).

[blackba]

I think you could have DVC setups in guitar speakers, but since it wasn't done in the past, no one has switched to it. Much like 1/4" jacks, speakon connectors clearly have many benefits over 1/4" jacks, but very few new guitar amps or cabs have them as options. Unlike PA cabs which have pretty much switched over completely.

Guitar speakers are a pretty backward looking industry (lots of people looking to capture vintage speaker tones), unlike Car audio which is always trying to out thump what it did last year.

[teleharmonium]

The main reason is that guitar speakers don't need high frequency response that you would get from the dual cone approach where the second cone handles the highs. Guitar speakers only need to go up to about 5K, they're severely rolled off above that.

[stratovarius]

Gauss used to make 'em.

[Darth Tater]

The main reason is that guitar speakers don't need high frequency response that you would get from the dual cone approach where the second cone handles the highs. Guitar speakers only need to go up to about 5K, they're severely rolled off above that.

You're thinking of the little 'whizzer cone' things with a smaller cone in the middle of the woofer. I'm talking dual voice coils...2 actual voice coils, each with the same impedance.

Such as this:
http://www.electronixwarehouse.com/graphics/diagrams/dvc2ohm.gif
(http://www.electronixwarehouse.com/graphics/diagrams/dvc2ohm.gif)

[~Abstract~]

You just use 1 of the 8 ohm coils. You don't have to use both, unless something changed since the last time I wired a DVC speaker (which has been a while!).


It's my understanding that the unused VC moving thru the gap will gain EMF energy...if you don't add some resistance. Potentially burning the coil.

It'll also change the T/S requirements so your box may not be optimal.

Generally you don't want to use only half of the motor.


I got flamed on a car audio site I frequent for asking this a long time ago...I've not forgotten. :D

[Tone_Terrific]

It's my understanding that the unused VC moving thru the gap will gain EMF energy...if you don't add some resistance. Potentially burning the coil.
A coil moving through a magnetic field will generate a potential voltage.....but an unattached moving coil will generate enough current to burn itself out?!?!? Somebody HAS to be kidding or basic physics was lying.

It'll also change the T/S requirements so your box may not be optimal.
Cone resonance should remain the same the impedance curve might vary, hardly a consideration in the vast majority of guitar applications.

Generally you don't want to use only half of the motor.Elongating the voicecoil to accommodate the extra wiring, which would also have to be worthy of the power at each impedance, is the most likely reason you will not see a lot of these, imo. The added complexity and expense is not needed. The weight should be negligible. Guitar cones are heavy and stiff, already.


I got flamed on a car audio site I frequent for asking this a long time ago...I've not forgotten. :DFlaming and accuracy of info are only vaguely related....maybe I missed something, that happens.:eek:

[Jef Bardsley]

DVC woofers are great if you have a stereo and only want to build one sub.

Otherwise.... would you pay more for a 4/16 ohm Greenback if it wasn't as loud and didn't sound like a "real" 8 ohm Greenback? (8 ohms would be half-power, so that doesn't really count as an equal option)

Basically, I'm saying speaker design is like guitar design - more art than science. If all you had to do was wrap an extra coil around the former, then sure... but I bet Jim has some stories about how much "fun" it was trying to duplicate the sound of the old pre-Rollas. Except for the color of the paint and the binding posts, everything on a speaker can be heard, and if you change one thing, changing everything else to get you back where you started is dreadfully tedious.

Maybe I'm wrong, maybe a 1x12 that had the same 4/16 ohm options as a 4x12 would be a hit, but I'm thinking like TT. The cost and complexity aren't worth it for a very small market share.