Split coil Fi? Sexiness!

[galacticmonkey 5,000+ posts]

Im going to need more subs soon. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[Reimers 10+ year member]

cerwin vega used a split coil in the stroker and stroker pro

 

[galacticmonkey 5,000+ posts]

Im going to need more subs soon. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[Reimers 10+ year member]

cerwin vega used a split coil in the stroker and stroker pro

 

[bass_lover1 10+ year member]

5'8 Pat ..sound like I'm a 6'9 prize fighter that will rip the soul out of any being through the phone lol.

In all seriousness there is no issue doing some 'normal' split coil type stuff either...the Alumapro M-16 is still one of my favorite subs of all time //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif..and it is very practical...

The carbon mids are a split coil design...with 11.2mm of xmax on the 6.5, still my favorite mid to date..things will get down and boogie in the low end (60Hz range with ease) and still play within +/- 3dB up to 5500Hz //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

5'5", 5'8" what's three inches? //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[Kyle_Keating 10+ year member]

As Neil point out, this coil can be used for more than one kind of motor.

underhung motor - ends up being a linear design (with proper spacing between coils) with overall lower average BL than a standard overhung design with a simialr size magnet and xmax limit. This is be very simialr to the current RE-xxx

use this coil (wire each out of phase) and then use it with two overhung gaps with reverse magnetic polarity and you have the JBL design - its a non-linear design that improves power handling by increasing the surface area of the coil by 2. This design yields a BL curve much like a standard overhung non-linear design. beyond xmax you enter a negative BL and the coil breaks - natural limit of the design.

Careful about inductance. The majority of the inductance comes from the thickness, number of layers, on the coil. JBL does have natural cancellation but not in the same area so its not a true cancellation. They also use less L which is deceiving because they have a lot less inductance simply from that alone. I have seen high and low inductance with nearly every kind of design. You also have to account who and how the inductance was measured. Not all measurements are the same.

 

[NDMstang65 10+ year member]

As Neil point out, this coil can be used for more than one kind of motor.
underhung motor - ends up being a linear design (with proper spacing between coils) with overall lower average BL than a standard overhung design with a simialr size magnet and xmax limit. This is be very simialr to the current RE-xxx

use this coil (wire each out of phase) and then use it with two overhung gaps with reverse magnetic polarity and you have the JBL design - its a non-linear design that improves power handling by increasing the surface area of the coil by 2. This design yields a BL curve much like a standard overhung non-linear design. beyond xmax you enter a negative BL and the coil breaks - natural limit of the design.

Careful about inductance. The majority of the inductance comes from the thickness, number of layers, on the coil. JBL does have natural cancellation but not in the same area so its not a true cancellation. They also use less L which is deceiving because they have a lot less inductance simply from that alone. I have seen high and low inductance with nearly every kind of design. You also have to account who and how the inductance was measured. Not all measurements are the same.

The WGTi is a single layer edge wound coil...

What's this about 'natural cancellation' ?

 

[ciaonzo 5,000+ posts]

The WGTi is a single layer edge wound coil...
What's this about 'natural cancellation' ?

I think he's suggesting that it's not a bifilar coil.

Also, Kyle, with the Differential Drive, wouldn't both magnet assemblies have a positive magnetic charge so that when one coil is wired out of phase, the non-linearities in the BL curve are effectively canceled due to the face-to-face orientation of the motors? Or is that not the case with this one?

And did you mean the motor brakes, as in dynamically, as opposed to "breaks"? That would not be cool if your coil breaks.

 

[MegaloJntariac 10+ year member]

Split coil is the opposite of XBL^2; in their most basic forms, XBL^2 has two gaps and one coil, split coil has one gap and two coils. Split coil's advantage is more linear BL and lower inductance than your standard overhung design.
Differential Drive is quite different. It has way, way lower inductance than basically every subwoofer out there, and is well suited for high power handling.

I've been waiting for Scott to utilize more split coil for a long time now. Glad to see it happening.

Thanks for clarifying.

 

[80INCHES 5,000+ posts]

ahhhh i love motor talk

80

 

[negative3five 10+ year member]

Nick Could you post pics and a description of the XMX motor design and how the coil guide in it worked I like learning about motors to. I tried searching but all the pics don't work or all the old threads don't work because the forum is no longer active.

 

[Kyle_Keating 10+ year member]

The WGTi is a single layer edge wound coil...
What's this about 'natural cancellation' ?

Ok, to be correct then it would be "cross-sectional area"

electromagnetic fields of the two separate coils in the gti are opposing each other.

 

[Kyle_Keating 10+ year member]

I think he's suggesting that it's not a bifilar coil.



Also, Kyle, with the Differential Drive, wouldn't both magnet assemblies have a positive magnetic charge so that when one coil is wired out of phase, the non-linearities in the BL curve are effectively canceled due to the face-to-face orientation of the motors? Or is that not the case with this one?

And did you mean the motor brakes, as in dynamically, as opposed to "breaks"? That would not be cool if your coil breaks.

Only 1 magnet and two gaps.

Good observation - but be careful about the word 'linear.' What you are suggesting is true, but its not the non-linear effects that get canceled its the asymmetrical effects - and they only get canceled if the both gaps are nearly identical but (inverse on the y-axis)

When displacement goes beyond xmax, we see the bottom coil enter the top gap (or vice versa) One coil is out of phase from the other so the force vector quickly reaches zero and continues going the opposite direction during the gap switch (this is opposite of the input signal) So it makes for some considerable distortion, but its also a nice way to prevent mechanical damage without the issues of many extremely stiff spiders - which also have their own distortion issues.

 

[ciaonzo 5,000+ posts]

Only 1 magnet and two gaps.
Good observation - but be careful about the word 'linear.' What you are suggesting is true, but its not the non-linear effects that get canceled its the asymmetrical effects - and they only get canceled if the both gaps are nearly identical but (inverse on the y-axis)

When displacement goes beyond xmax, we see the bottom coil enter the top gap (or vice versa) One coil is out of phase from the other so the force vector quickly reaches zero and continues going the opposite direction during the gap switch (this is opposite of the input signal) So it makes for some considerable distortion, but its also a nice way to prevent mechanical damage without the issues of many extremely stiff spiders - which also have their own distortion issues.

I see. I didn't realize the motor was set up that way in the JBL. In a sense, it has two top plates but they're locate at either end of the motor, using the same slugs and that's what provides the revers magnetic field for one of them. I'd never considered the braking force that would occur in that configuration. Most interesting. What I thought it would look like inside the JBL is pictured first, which as actually a CoDrive product. The JBL is pictured below it.

I'm right with you on my misapplication of the term 'linear', thank you for pointing that out. I was indeed referring to any potential asymmetry of the BL curve if you were to reference a graph plotting BL product versus excursion. Linear would better describe a system like the LMS coil working within it's mechanical limits. As I said, sometimes I'm not very good at articulating things. Thanks for taking the time to chime in.

 

[yikes vR 10+ year member]

Just saw these. Here for who hasn't, pretty sweet.