So it appears I may have made my box a touch to large and now im concerned about my sub hitting the back of my seat.

I originally intended to recess the sub .75inches in a 1.5 inch thick ring. Not being familiar with the metric system I wasn't aware until about a hour ago of how big 27 mm Xmax was.

Unless im mistaken that means the subs cone will have a hair over 2 inches of travel from peak to peak before getting into distortion.

My concern lies with forward movement.

I figured for .75 inches of forward movement, to find out now after the box is being constructed by me ( out of fiberglass ), that I didn't figure right.

SO, how accurate is the 27mm measurment? Is it truely Xmax or is it actually Xlim??

Pic of my problem, sorry the pic is at a funk angle, the ring is touchig the seat ar the top of the ring/box. The ring is 16" and the sub is a 12" the pat that is touching is actually 2" above where the sub will be. Do you think I will be alright?

Edited July 25, 200817 yr by TwistedMind

xmax is measured via one way overhang of the voice coil.........i think xmech is double that(not too sure)..

There are 10 mm in a cm and 2.54 cm in an inch. So 25.4 mm in an inch. That's what I always remember as my baseline for how far things move in inches.

So with your 3/4" baffle the sub will only be moving out an extra .3 of an inch or so. based on where I guesstimate your sub is within that ring, you'll be fine.

That's not going to work...you'll wear the edge of the surround out and rock the suspension...

Already had 1 guy do that in a F150 with a pair of 10's...

OKAY NDMstang65, do you think a half inch baffel will adequetly support the Q ? I can get a 1 inch recess if I have to im just concerned about the sub breaking the baffel.

Scrapping the box isnt really an option as ive already got about 8 hours and 100 bucks into it.

first is the box sealed or ported and how much power do you plan on using. if it is sealed is it on the small side or large side of the box reccomendations. the submay be capable of a large xmax but you might not use all of it so you might be ok

first is the box sealed or ported and how much power do you plan on using. if it is sealed is it on the small side or large side of the box reccomendations. the submay be capable of a large xmax but you might not use all of it so you might be ok

I just added a 3rd baffel and recessed the sub 1.5 inches

the box will be ported eventually, I don't know the final volume yet its going to end up somewhere in the 2 - 2.5 range im hoping around 33 Hz

you will be fine if its ported you wont get as much excursion especially around tuning if powering it with 1k or less you probably wont see near full excursion unless you dont set your subsonic filter correct and you unload the sub i have a q 18 ported with 1 k on it in a huge box in my dakota extended cab before displacement it is 13.35 cuft tuned to 28hz with 174sqin port final volume around 9.75cu and i still dont see full excursion unless i try running a 20hz tone. most music on full volume i see about an inch of total travel maybe a little more. its nice and loud though, i can burp a 142.7@41hz not bad considering its tuned to 28hz and the lows are just amazing. 33hz tuning might be a little high if you want killer lows try 30-31hz