what gives you bl?

[jusBloud 10+ year member]

does the size of the motor have alot to do with the bl? the way the coil fits the gap? or how strong the actual magnet is?

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[SicAudio 5,000+ posts]

magnet strength ( not always size ) and the way it is designed in relation to the coil

 

[groundpound4200 5,000+ posts]

I always thought a tight gap usually equated to ahigh bl

 

[SicAudio 5,000+ posts]

relation of motor to coil yes it is 1 of the key parameters

 

[Toxic Tuan 10+ year member]

There are two parts to BL. The B which represents the motor strength and the L which represents the inductance. For example: the same motor (same B) with different coils (L1 and L2) will have different BL values. How tight the coil sits in side the gap isn't a direct correlation to BL. The B variables are magnet size, grade, gap size, etc. The L variables are number of turns, height, grade, etc. With that being said: yes there is a best coil for a specific motor dependent upon operations.

Tuan

 

[Villeza1 10+ year member]

There are two parts to BL. The B which represents the motor strength and the L which represents the inductance. For example: the same motor (same B) with different coils (L1 and L2) will have different BL values. How tight the coil sits in side the gap isn't a direct correlation to BL. The B variables are magnet size, grade, gap size, etc. The L variables are number of turns, height, grade, etc. With that being said: yes there is a best coil for a specific motor dependent upon operations.
Tuan

Wow, I just learned something new today! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[Haunz 10+ year member]

Wow, I just learned something new today! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Sorry, no you didn't...

B is the magnetic force.. L is the length of wire in the magnetic force field..(measured in Tesla-meters)

Stronger magnets, tighter gap, larger coil diameter, and thicker top plates will all increase BL product..

 

[SicAudio 5,000+ posts]

now you have learned something lolz

 

[Kyle_Keating 10+ year member]

To add to what Haunz's said.

BL is also relative to the coil's resistance. So you cant just look at the BL and know if its high or low, you really have to look at the Resistance too. The formual for calculating the net force factor is BL^2/Re. With that number you can compare any two speakers and know which one has a stronger motor at the small signal. Note: Most speaks have some non-linear effects closer to xmax and the BL can drop dramatically, even as much as 50% which not only lowers the presumed low frequency or high signal sensitivity, but increases distortion. After all BL is simply a curve, so its somewhat inappropriate to compare two curves with just two points.

 

[jusBloud 10+ year member]

this is getting good

 

[Toxic Tuan 10+ year member]

Sorry guys if my info is incorrect or is poorly written. That is exactly how an tech at one of the major subwoofer manufacturer described it to me as. Let me try to re-phrase: "indirect correlation." L is indeed the length and I described it in terms of physical size. Motor topology and terminology isn't my good area.

Tuan