Difference in coil type.

[412 CVX]

so i guess nno one has heard of Kapton voice coils? hmm must be in low end subs then

i've never even heard of them. but my extensive research (30 second google search) tells me they're made of plastic... which doesn't sound right. i'm thinking it might be referring to the voice coil former, but again, not sure.

[KenC210]

Ok found somethings just now

3 What is the difference between Kapton and aluminum voice coils?

Kapton is a non-conductive material and is therefore not influenced by the eddy-current effect like aluminum, when situated in a magnetic gap.

In practice this means no mechanical brake and therefore a very high mechanical Q-factor and low Mechanical resistance.

Drivers with Kapton voice coil former often perform a more detailed midrange with higher dynamic and less coloration and distortion.

Due to the lack of mechanical brake, we do not recommend the use of Kapton drivers as bass driver, because if the x-max is exceeded there is nothing to prevent the driver from bottoming out. For sub woofer applications, please use drivers with aluminum voice coil formers.

For use in the drivers with 77 mm and 102 mm voice coils, we have made a hybrid between the two - the Kapton Alu system (KA system). It utilizes the advantages from both systems. When the driver is within it´s x-max, the voice coil works as a Kapton voice coil but if the driver exceeds x-max, it works like an aluminum voice coil, braking the cone.

Drivers with Kapton voice coil former, can have a tendency to a more pronounced break-up before roll off, because of the lack of mechanical brake.

anyone capable of explaining this??

other references http://www.diyaudio.com/forums/multi-way/102842-voice-coil-formers-kapton-vs-nomex-vs-aluminum-vs-gf-til.html

What's the difference in sound between paper and kapton/synthetic voice coil formers? Is the choice of material substantial to the sonic character?

Larry, despite the fact that using a paper former is a great marketing tool for vintage style speakers, the fact is it has no effect on the sound itself. It, like Kapton, is a diamagnetic material, and it's effect on the magnetic field and the effect of the magnet field on the former itself is negligible. The big difference is in the mass, or weight of the formers. In the early 70's when the race was on to have the highest powered solid state amp, speaker manufactures had to keep up by making their speakers take alot of power. Therefore, Kapton was put into use. Because the Kapton is thicker, heavier, etc. (a typical one looks like an orange plastic pill bottle), it takes alot of power to get it moving. So, the movement was to heavier Kapton voice coils, heavy, damped cones, and damped surrounds for a high powered, relatively low sensitivity speaker. Now we're going the other way. Low powered amps, light weight speaker components, and high sensitivity to make the lower powered amps sound huge. The one possible exception to the coil former having an effect is the use of an aluminum former. Some believe that since it is a closed loop of metal, there are 'eddy' currents circulating in the former. These eddy currents could affect the sound by causing a braking action to voice coil movement, thereby increasing the damping of the speaker.

[412 CVX]

Ok found somethings just now

3 What is the difference between Kapton and aluminum voice coils?

Kapton is a non-conductive material and is therefore not influenced by the eddy-current effect like aluminum, when situated in a magnetic gap.

In practice this means no mechanical brake and therefore a very high mechanical Q-factor and low Mechanical resistance.

Drivers with Kapton voice coil former often perform a more detailed midrange with higher dynamic and less coloration and distortion.

Due to the lack of mechanical brake, we do not recommend the use of Kapton drivers as bass driver, because if the x-max is exceeded there is nothing to prevent the driver from bottoming out. For sub woofer applications, please use drivers with aluminum voice coil formers.

For use in the drivers with 77 mm and 102 mm voice coils, we have made a hybrid between the two - the Kapton Alu system (KA system). It utilizes the advantages from both systems. When the driver is within it´s x-max, the voice coil works as a Kapton voice coil but if the driver exceeds x-max, it works like an aluminum voice coil, braking the cone.

Drivers with Kapton voice coil former, can have a tendency to a more pronounced break-up before roll off, because of the lack of mechanical brake.

anyone capable of explaining this??

other references http://www.diyaudio.com/forums/multi-way/102842-voice-coil-formers-kapton-vs-nomex-vs-aluminum-vs-gf-til.html

What's the difference in sound between paper and kapton/synthetic voice coil formers? Is the choice of material substantial to the sonic character?

Larry, despite the fact that using a paper former is a great marketing tool for vintage style speakers, the fact is it has no effect on the sound itself. It, like Kapton, is a diamagnetic material, and it's effect on the magnetic field and the effect of the magnet field on the former itself is negligible. The big difference is in the mass, or weight of the formers. In the early 70's when the race was on to have the highest powered solid state amp, speaker manufactures had to keep up by making their speakers take alot of power. Therefore, Kapton was put into use. Because the Kapton is thicker, heavier, etc. (a typical one looks like an orange plastic pill bottle), it takes alot of power to get it moving. So, the movement was to heavier Kapton voice coils, heavy, damped cones, and damped surrounds for a high powered, relatively low sensitivity speaker. Now we're going the other way. Low powered amps, light weight speaker compon having an effect is the ents, and high sensitivity to make the lower powered amps sound huge. The one possible exception to the coil formeruse of an aluminum former. Some believe that since it is a closed loop of metal, there are 'eddy' currents circulating in the former. These eddy currents could affect the sound by causing a braking action to voice coil movement, thereby increasing the damping of the speaker.

what i'm taking from the article is that kapton VC formers are heavier, but handle power better than their lighter weight counterparts. however, since they are heavier, it takes more power to get them moving. this,if i interpreted correctly, potentially translates into a loss of accuracy, especially among higher frequencies. kapton is a plastic, therefore it doesn't have any affect on the magnetic feild/current and is not prone to the "eddy" currents like aluminum is. this translates to less mechanical resistance on paper. however there is no mechanical "brake" to stop the woofer from bottoming out when it's operating outside of it's xmax.

aluminum has more of a "brake" to prevent the dreaded bottom out, but is prone to "eddy's" (which i still don't understand). i think i read somewhere that this can cause distortion... not sure.

paper formers are the lightest, but do not handle heat as well as some others.

i may just be bullshitting here, but that's my interpretation.