Specs for Subwoofers

[Marchant89]

What’s the most important specs when looking at subwoofers for spl? Motor force, db, x max?

[SnowDrifter]

No one answer. There's a lot of interplay depending on what you want to do.

It's like buying a car, and asking what the most important feature is.

Short answers:
- Power handling appropriate for your needs
- QTS for ported / sealed applications. Lower QTS is more appropriate for a ported box, higher for sealed. But don't get too hung up on this because there's a litany of exceptions and install dependent variables. Just know it exists.
- xmax has an interplay here, but is not the sole decider. Subwoofer drivers need to displace a sizable quantity of air. All other factors equal, you can displace more air wit a driver that has a higher xmax. Again, don't get too hung up about it.
- Higher impedance results in higher damping factor from the amp. i.e. the amplifiers ability to mechanically brake the inertia of a cone when the signal stops

Anecdotally... And I have no data to back this up outside of some small-sample-size personal observations.... But for daily builds: I like drivers that have a very high BL^2/RE (motor force) for a given amount of cone area, with the lowest impedance coils I could possibly find (I simp for 0.35 coils), with stiff suspension, in a medium to larger box tuned fairly low with a medium to low amount of port area. Not the loudest enclosure, but they've always given me a rather ridiculous response range(think from 15-17hz up to 50-60+) with no muddiness / odd resonances, or issues with transient response / group delay artifacts.


TL;DR: Don't sweat individual specs. Just buy a driver from a reputable company that'll handle the power you need to throw at it, then make a box to suit your needs. Pay mind if the manufacturer indicates the driver is intended for sealed or ported use.

[Marchant89]

So I am really looking at either Fi teams or Fi neo 4.9 or 4.11 I usually wire at .5 with 2 15s I’d like to upgrade coming from the Ssd v4 only running a crescendo bc6k at .5 so really just trying to gain around 3 dbs im around 147db now the only thing that sets the neos apart are almost 100g more motor force x max and db basically the same +/- 1db also looked at the incriminator judges