Xmax - how does it affect spl and overall sound?

[xephonics 10+ year member]

Ok I know it stands to reason that higher xmax = louder subs, but is it in some kind of proportion? like double xmax = ( original DB's) * X?

or is it different?

im a pseudo newb (as you should be able to tell from this question), but with the new RE on the horizon, I'm wondering if almost double the xmax of previous versions, how much louder this beast will be.

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[xephonics 10+ year member]

bump, id really like to know :/

 

[helotaxi 5,000+ posts]

Xmax CAN indicate the ability to get loud. I say can because you have to be able to get the sub to Xmax in a suitable enclosure at a suitable frequency for it to make a difference. You can, for instance, get most subs to reach the limits of their travel below the tuning frequency of a ported enclosure, but they will produce almos no output at that frequency. In a ported enclosure, the most efficient frequency is also the one where the cone travels the least. To get the cone to move more and produce more output at that frequency requires an absolutely stupid amount of power and SPL setups rarely get to the mechanical limit of the sub. Usually you will thermal the coil or the forces invloved (massive air pressure changes) will tear the cone to shreads before you actually get the sub to its max excursion.

Most of the so called "super-subs" were designed as sound quality drivers. They have a large Xmax to ensure that the sub stays within its linear operating range at high volumes. The large Xmax (and ability to get pretty loud) was a byproduct of the design rather than a design goal in itself. Many dedicated SPL oriented subs don't have a very large Xmax but they have a strong enough motor to use all the available travel right around tuning and as a result can get frighteningly loud without having a large Xmax.

 

[tobz 10+ year member]

I follow that guy around for a reason ^ //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[xephonics 10+ year member]

ahhh, thx helotaxi //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

so the new RE sub is most likely to have a better SQ at higher volumes than say the XXX, but it is not technically meant to get louder, just to sound better at the higher volumes?

 

[helotaxi 5,000+ posts]

It will have a larger range of volumes at which it can sound its best.

 

[xephonics 10+ year member]

gotcha, now it makes sense (mostly )

 

[scottrc5391 10+ year member]

Is there anything Helotaxi doesn't know? I understand what you are saying and how x-max really only shows a range of volumes the sub can play well at, but I'm still a little confused. How can a sub at lower excusion play louder than one at higher excursion? If surface area and xmax were the only factors determining output that wouldn't make sense. The louder sub at lower excursion would have to have more cone force than the sub at higher excusion right? The force is really the determining factor right? thanks.

 

[kickerlivinloud 10+ year member]

Is there anything Helotaxi doesn't know? I understand what you are saying and how x-max really only shows a range of volumes the sub can play well at, but I'm still a little confused. How can a sub at lower excusion play louder than one at higher excursion? If surface area and xmax were the only factors determining output that wouldn't make sense. The louder sub at lower excursion would have to have more cone force than the sub at higher excusion right? The force is really the determining factor right? thanks.

Someone correct me if I am wrong but at lower excursions that cone is able to go back and forth much faster than 1 long excursion. Some in the time the 1 long excursion happens several samller excursions can happen. I don't know if that is right or not but it makes since to me....

Jon

 

[nweibley 10+ year member]

Most of the so called "super-subs" were designed as sound quality drivers. They have a large Xmax to ensure that the sub stays within its linear operating range at high volumes. The large Xmax (and ability to get pretty loud) was a byproduct of the design rather than a design goal in itself. Many dedicated SPL oriented subs don't have a very large Xmax but they have a strong enough motor to use all the available travel right around tuning and as a result can get frighteningly loud without having a large Xmax.

Point madeD 9915... one hell of an SPL sub, but the X-max is nothing insane.

RE XXX... great sound, flat response, gets loud, but nothing insane. Lots of linear travel.

If you put two DD9915s vs 2 15 XXXs with 3000w or more, the DDs would tear the XXXs a new *******. If you put the DDs against the XXXs in a nice sealed box, the DDs would bottom out often and not be anything special, and the XXXs would sound very nice... so no, x-max is not everything.

 

[scottrc5391 10+ year member]

Yep, we can't judge a sub only by its x-max or magnet size. And about the excursion, the cone must move faster at 10 mm excursion than at 2 mm at the same frequency because it must cover more distance (move more) in the same amount of time. They both move at same frequency, but the one with the farthest throw must move the fastest (linearly) to maintain the same frequency. If you have two of the same sub at different excursions, the one with furthest excursion obviously must be louder due to more air displaced and if I'm right, more force in doing it. What I'm saying though is that maybe the SPL sub (designed to get loud at lower excursions) moves with more force than a higher excursion sub. Heck, I don't know.