Pros/Cons of large voice coils?

[theAnonymous1]

I have a pair of 12" subs that have dual 6.5" voice coils. I can fit my my hand inside the center motor vent.

Just curious as to why they were designed this way as it's not very common to see 6.5" voice coils. Is there any real advantage to this design?

[NEO Dan]

Could be interesting, what are they? Pics?

[theAnonymous1]

Well, I didn't want to mention the brand as I wanted to stay on topic without their cheesy reputation getting in the way. Maybe after one of you smart folk share some insight on the subject I'll post what they are.

[AndrewT]

power handling, or BL product, or ??

[pinkmouse]

Power handling and cooling usually.

[weltersys]

Originally Posted by theAnonymous1

I have a pair of 12" subs that have dual 6.5" voice coils. I can fit my my hand inside the center motor vent.

Just curious as to why they were designed this way as it's not very common to see 6.5" voice coils. Is there any real advantage to this design?

Larger voice coils have more surface area which aids in cooling, reducing power compression.

A larger voice coil pushes against more cone surface area, which can result in less cone flex.

6.5" seems overly large for a 12", perhaps the driver is a "smaller brother" using a voice coil designed for use in an 18" or 21", similar magnet structures and voice coils are often used with different size cones to reduce design and tooling costs.

[tinitus]

Originally Posted by theAnonymous1

.......6.5" voice coils. Is there any real advantage to this design?

hmm, being this big, I think it gets exceedingly diffult to make the voice coil precise and sturdy
might go againts the possible advantages

but regarding the cone, they only need to make sure the area between voice coil and surround is really tough
the rest could be just a big dust cap

but the much smaller spider will be stiffer and less 'flexible'

[theAnonymous1]

Here are the specs I just measured (both VC in parallel).....

* f(s)= 22.88 Hz
* R(e)= 1.05 Ohms
* Z(max)= 10.57 Ohms
* Q(ms)= 4.873
* Q(es)= 0.536
* Q(ts)= 0.483
* V(as)= 30.550 liters (1.079 cubic feet)
* L(e)= 1.07 mH
* n(0)= 0.07 %
* SPL= 80.24 1W/1m
* M(ms)= 465.20 grams
* C(ms)= 0.10 mm/N
* BL= 11.43

And at the risk of being told to just toss them in a pit and light them on fire, here is a pic.....

[revboden]

Originally Posted by theAnonymous1

I have a pair of 12" subs that have dual 6.5" voice coils. I can fit my my hand inside the center motor vent.

Just curious as to why they were designed this way as it's not very common to see 6.5" voice coils. Is there any real advantage to this design?

The answer is: It depends.

The number of windings, the length of the wire, the material the former is made of, the diameter of the wire etc...

My guess, since you say the driver has a cheesy reputation [cough]car audio[/cough], it's for heat dissipation / sheer size (mines bigger).

[theAnonymous1]

Originally Posted by revboden

.... My guess, since you say the driver has a cheesy reputation [cough]car audio[/cough], it's for heat dissipation / sheer size (mines bigger).

Well I let the cat out the bag, so I think you are half right at least.

They didn't market this as their highest power driver, and the higher power drivers had smaller voice coils, which made me question why they went with such a large voice coil here. Just a gimmick?