wanna see why TC sounds doesnt use aluminum cones anymore???

[dcole18 5,000+ posts]

Even the 3" coil is generally going to be wound thicker than a regular coil, that is what I meant, not the fact that most use a 4" coil. But yea, the BL and Le is not a horrible trade off if you have the space for the drivers as they perform amazingly.

iirc the lms coil actually uses the same amount of copper as a regular 3" Tc9 coil

so no, it doesnt weigh more

 

[snoopdan 5,000+ posts]

I dont think anyone is using this thread to bash TC, but it is what it is - ya know ?

 

[bose301s 5,000+ posts]

iirc the lms coil actually uses the same amount of copper as a regular 3" Tc9 coil
so no, it doesnt weigh more

Never said it weighed more either, the lobes on the coil are obviously thicker wound than the valleys, that means a standard 8 lays coil may be 10 or 12 layers at the thick point and only 4-6 and the thin points, those extra layers at the thick points means that the gap must be larger to accommodate it, it has nothing to do with the weight.

 

[dcole18 5,000+ posts]

Never said it weighed more either, the lobes on the coil are obviously thicker wound than the valleys, that means a standard 8 lays coil may be 10 or 12 layers at the thick point and only 4-6 and the thin points, those extra layers at the thick points means that the gap must be larger to accommodate it, it has nothing to do with the weight.

nvm, i lied //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[bose301s 5,000+ posts]

yes, and the gap being so wide is what makes the enclosure requirements so screwy...
we both know this //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

I know, I just wasn't coming off clearly so i felt like explaining, lol.

 

[delvryboy 5,000+ posts]

Old video, but lets take a look at it for the fun of this thread.
ps. this is really old news...but fun to watch.

lol... that's what all the flat cone 15A's did.

 

[mtlhead 10+ year member]

meh, ive been running my TC 1000s for over a year with 2kw with no problems

 

[revrider1 5,000+ posts]

Dam, I hope mine dont do that... lol

 

[Kyle_Keating 10+ year member]

Also LMS is a HUGE coil and large gap increasing Le and also decreasing BL, but they handle a lot of power and from what I have heard are slightly more linear than XBL^2 drivers. XBL^2 generally has lower power handling and a smaller gap which can cause problems if there is any coil rock. IMO split coil is the coolest tech, but also the hardest to implement and uses a lot of power, lol.
Anyway, definitely take pics of the LMS coils, I want to see some of them out of the driver.

I have foun that split coil is the least efficient design also, and it also is difficult to make it linear because you are minimizing the coil with respect to the fringe field so its more susceptible to non-linear behavior. - hard to get a flat bl curve at least in my modeling.

I have programmed software to dynamically model motors, actually i'm writing a paper on the whole deal to lay to rest many of the misconceptions about the motor topologies.

For example, LMS does not have a "huge" coil for example, its bigger than xbl but its also smaller than the standard overhung design. The gap's for and lms can be made the same, that has nothing to do with the variable coil wind... split gap can be made to be as linear as lms, it just requires more attention to asymmetrical flux density behavior.. There are a lot more details than just that, but i have gone thu iterations after iterations because I wanted to know what some of the fundamental differences were too, but just working from a hunch was not good enough or me. I was actually surprised by some of the results I found

 

[Kyle_Keating 10+ year member]

yes, and the gap being so wide is what makes the enclosure requirements so screwy...
we both know this //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

you guys have it backwards, lol.

think of it like this.

take a standard 4 layer overhung coil, say its 60mm winding width in a 10mm gap, This give you an xmax of about 25mm.

and LMS design would then start from 4 layers and work down. On average the LMS coil would have 2.8 layers in the gap within +-50mm.

thats how it works. Gaps dont get wider, coils dont get heavier.

you CAN make the gap wider and add more L, but then you're just changing the reference point.

 

[J31Rob 5,000+ posts]

dcole, i wanna see your collection.

 

[Kyle_Keating 10+ year member]

Ah, that is a disadvantage of a metal cone, it can "ring", ie. vibrate at a seperate frequency unintentionally due to the fact that metal is very acoustically alive. Paper is in some ways a better choice as it has better dampening characteristics. They all have their disadvantages and advantages though.

yes you're right.... and this happens around 2,000Hz.

if you wanted to use your subwoofer up there, i would say look for a paper cone, and while your at it... very low inductance and high sensitivity.

 

[Kyle_Keating 10+ year member]

powder coat.

...its really hard to anodize titanium and make it look pretty.

 

[NDMstang65 10+ year member]

I have foun that split coil is the least efficient design also, and it also is difficult to make it linear because you are minimizing the coil with respect to the fringe field so its more susceptible to non-linear behavior. - hard to get a flat bl curve at least in my modeling.

If built/designed properly a flat response curve (which is really what matters) isn't hard to achieve...

You don't listen to Bl curves //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[bose301s 5,000+ posts]

yes you're right.... and this happens around 2,000Hz.
if you wanted to use your subwoofer up there, i would say look for a paper cone, and while your at it... very low inductance and high sensitivity.

Ok, I didn't know what frequency it happened at, thanks for clarifying it.

Anyway, you used to work for TC correct? You helped design the LMS tech and other stuff? If you are that kyle PM me, I would love to pick your brain and get some more education on this stuff.