Underhung TC Nomz

[ciaonzo]

Been after one of these for years, finally got a pair.

[gckless]

Gimme!

What's the model/name of those motors?

[J31Rob]

fapfapfap

[Linkz]

Dem some nice woofers

---------- Post added at 12:02 AM ---------- Previous post was at 12:02 AM ----------

xmax?

[ciaonzo]

Gimme!

What's the model/name of those motors?

It's basicaly a beefed up MASS able to drive the shit out of a port (MASS drivers were designed for sealed applications). A nice 10 layer flatwind with a Kapton former, nice and light to stay snappy tight.

[gckless]

It's basicaly a beefed up MASS able to drive the shit out of a port (MASS drivers were designed for sealed applications). A nice 10 layer flatwind with a Kapton former, nice and light to stay snappy tight.

Ahh ok. What are the advantages/disadvantages of a coil that short?

[Beatin']

Ahh ok. What are the advantages/disadvantages of a coil that short?

I was just going to ask that. It is very unusual.

I would guess that with triple stacked magnets and high Xmech, the coil needs not be so long. It's probably the same amount of wire found in the usual 4 layer 2.5" DVC subs, but compressed........with 10 layers.

[ciaonzo]

Ahh ok. What are the advantages/disadvantages of a coil that short?

Underhung is usually intended for very low distortion applications. Obviously, there's much less moving mass and inductance so very good for wide bandwidth use. BL is more linear than overhung so THD stays very low, but it's like a brick wall when it's done.

[gckless]

Underhung is usually intended for very low distortion applications. Obviously, there's much less moving mass and inductance so very good for wide bandwidth use. BL is more linear than overhung so THD stays very low, but it's like a brick wall when it's done.

Ok. I understood the reason behind underhung, guess I just never seen a flux diagram with an underhung motor. So, with the shorter coil, the entire coil should stay within the main motor force area (don't know what that's called ) throughout the full stroke? As opposed to a longer coil that would have part of the coil inside, part of the coil outside on each side of it's stroke. What are the differences there?

[hispls]

Ok. I understood the reason behind underhung, guess I just never seen a flux diagram with an underhung motor. So, with the shorter coil, the entire coil should stay within the main motor force area (don't know what that's called ) throughout the full stroke? As opposed to a longer coil that would have part of the coil inside, part of the coil outside on each side of it's stroke. What are the differences there?

In underhung the coil stays within the gap through the whole stroke. Original RE XXX was underhung and AFAIK MT was as well. More often used in midrange. You save mass for sure and get a very even BL curve until the coil leaves the gap. As OP stated, they're great until you get into big excursions. Big downside from manufacturing standpoint is you need a big arse top plate.

[nu2spl]

damm those are nice,what do these run?what kind of power do they like?

[Go2Sleep]

Nice find ciaonzo! I almost picked up a SVS proto with the same motor.
Wish I had picked it up now ;(

[sundownz]

Pretty sweet ; I am doing an under-hung project too w/ 60mm TP / 25mm coil / full copper pole sleeve.

Have always had a soft spot for the under-hung design -- used to have a prototype TC Sounds unit as well with that same gap treatment, it got down big time and sounded great.

[ge_off_me]

Since this has the copper ring on the inside, doesn't that classify it as an xbl2 motor?

[sundownz]

XBL has to do with grooves on the top plate and pole :