Xmax

[wanderer1]

Whats with xmax ratings? Example, Boston claims 13mm xmax on their G2's then tell you they move 1 inch both ways. Seems that most woofers exceed their claimed xmax, so what good is it when choosing a sub? Thanks if this question is noob, I just don't get it.

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[wew lad 5,000+ posts]

Xmax

I like google

 

[massivespl]

Companies rate stuff different. Like the sundown nsv3 is 40mm at 70% BL and then the dd 9500i says 30mm at 50% BL

 

[wanderer1]

so really not a good way to judge when making a purchase?

 

[massivespl]

so really not a good way to judge when making a purchase?

No not really. I mean more excursion means more air movement most likely but no I would not buy a sub because of it's xmax rating

 

[raptor727 10+ year member]

@massivespl ; off topic here but are you only running four batteries on two xs8k's??

 

[massivespl]

[quote name='raptor727']@massivespl ; off topic here but are you only running four batteries on two xs8k's??[/QUOTE]
Four 31s in the back and a northstar 34 under hood and two 350 alts.. When I had both amps at 1ohm each I stayed 13v full tilt.. I'm about to wire both amps to .5ohm and shits gunna get real. Hopefuly lol

 

[raptor727 10+ year member]

Nice man. I have a 350 and 140 and couldn't hold 12v with four agm's on a NS1 @ .25 ohm lmao

 

[adulbrich 5,000+ posts]

I'm about to run an M4a on 5 group 49's (400 ah total). I've got a 320 amp alternator. Going to add a 370 amp one before I get another M4a and strap so each sees .5 before rise. I'm somewhat surprised about Massive running some 8k's on four 31's and a 34. He has quite a bit of alternator though.

OP, Xmax is good, but as stated, companies rate different. The more that a sub can move in a linear fashion, the better. Some companies rate it by actual mechanical clearance. You don't want to get the sub too close to mechanical limits, or bad things will happen (hit back plate or jump the gap).

 

[Haunz 10+ year member]

XMAX should be stated as coil in gap

Many companies state XMAG, which is at 70% BL, and is generally considered to be the point where further loss in BL becomes audible. I've never seen anyone rate it at 50% BL, but if DD does at least they are forward about it and state so in the spec.

XMECH is the most the sub can move mechanically

When you see a rating from a company such as Boston, Pioneer, whatever, it is most likely the XMAG spec they are giving you, unless otherwise stated.