Random question about big surrounds on some subs...

[Staynlean 10+ year member]

So obviously some subs have some HUGE surrounds on them, does having this extra linear ability/motor force sacrifice cone area?

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[LosIsATool 5,000+ posts]

It's a dumb thing to do, they are separating from the basket and spiders, it's not any better.

 

[d77543020 10+ year member]

big surrounds are the new big motor it makes the sub look beefy and more attractive

 

[big scott]

is that it ?

i was thinking these subs have more excursion ? meaning more spl ?

 

[Staynlean 10+ year member]

is that it ?
i was thinking these subs have more excursion ? meaning more spl ?

Right, I was wondering if there's any specs somewhere that show the possible limits of cone area and where higher excursion and more motor force would start to be an advantage???
No idea if any such thing exists...

 

[brian84corvette 10+ year member]

if you mean - is the fat rubber surround on the subs sacraficing cone area for the added ability to x max movment more

yes its a give and take situation. give up some cone - get more throw

from what ive gathered around the net - subs with this type of fat surround have a diffrent sound to them as well

maby because the surround is so huge it acts like part of the cone in some ways - that a normal surround does not

 

[Staynlean 10+ year member]

if you mean - is the fat rubber surround on the subs sacraficing cone area for the added ability to x max movment moreyes its a give and take situation. give up some cone - get more throw

from what ive gathered around the net - subs with this type of fat surround have a diffrent sound to them as well

maby because the surround is so huge it acts like part of the cone in some ways - that a normal surround does not

Right on man, I was actually wondering about that as well.

 

[T3mpest 10+ year member]

You lose very little cone area using a fat surround. 1/2 of the surround is considered part of you cone area. You don't lose motor force, but you do increase weight which is similar, since your moving a heavier cone. That lowers effeciency on the top end of the bass spectrum while increasing your output down low with a given box size, good for when you want lots of low bass in a small box.

Over the last 10 years subs have come a long way. The original high xmax was was probably the JLw7. Standard motor design, but they made a custom basket and a nice long coil to increase excursion along with decently beefy softparts, good for 30mm one way or so. On the online front, Adire audio came out with XBL^2 which greatly increased the subwoofer motors linearity, pushing xmax to around 30mm as well, however the standard off the shelf 12 spoke baskets were only good for about 35mm on the inward stoke, so this was about the limit, even if XBL^2 could do more. After that it was on, lots of companies started using XBL^2 and other companies followed JL audio's design philosophy and used standard motors and long coils to get high xmax, relying mostly on the softparts and coil. We started seeing TC sounds with the rubber surrounds, larger spiders, and their TI baskets good for 45mm of xmax or so. Their new basket was the gamechanger for todays market, allowed them to push past the 35mm mark, even if their softparts were able to be damaged easily if you went much past it. (dented cones, ripped spiders, were somehwat common still) Anways, surrounds are currenlty the weak link in overbuilt subwoofers. TC sounds patent is expired any company that wants to use the TI basket can, so baskets are good for 45mm if you want them to be. Large and long 3 and 4inch coils are the norm, 10+inch spiders are common and companies learned from TC's issues in the car audio realm, they are durable now and soft bottom, instead of hard bottoming like an LMS Ultra will do.. The main issue is most companie still use the same oversized foam and rubber surrounds we have been using since drivers were in the 20-30mm xmax range. While the surrounds CAN reach past the 30mm mark, they really begin to get tight once you get past 20-25mm or so. The surrounds like what sundown uses don't do that and are linear well out past 30mm, just like his spiders and custom basket can support.

The "sound" what your hearing is increased linearity. It's a lack of the surround tightening a bunch, which raises the FS of the woofer and makes it punchier. A light cone also raises FS and a big surround sub tends to be heavy. So it's sound is quite a bit different than most, some like it, some don't, similar to XBL^2. The suspension tightening is distortion, but mostly second order so it generally doesn't sound "bad" and in most cases gives a linear response once you add cabin gain on top. Poeple accuse the new Sundown X and Z of not being able to play high. It's not that they can't play high, they just don't play high as loud as some, since they are heavy and ineffecient up top PLUS the don't gain exaggerated high end at high excursions, they start as a low end monster when they are barely moving and stay that way even when moving 60mm peak to peak.