^ It is going to take more force to control the larger cone but most 15s have a larger motor to accomplish it. Plus if you are looking for a certain amount of output, a 15 won't have to move as far to get there compared to a smaller driver (albeit you could just use more smaller drivers but that's a whole new set of problems)

Generally the only caveat with using larger drivers is that it is even more important to get your midbass right.

 

It's tricky because there are a great deal of 10" subs that don't have enough motor to control the cones properly. It's more an issue on proper driver choice for the space you have available. I'm a fan of good 15's because they can do everything you need and do it efficiently. depending on how high you need them to play, sometimes you need some more serious midbass like dedicated 6.5's or even 8" midbass drivers.

 

I use a OZ Matrix Elite 15 in my SQ CX-7. It's a beautiful SQ driver. I use dedicated 8's up front for midbass.

 

^^these guys know of what they speak...15's are great...if you have the midbass to keep up, otherwise your system will be very bass heavy and may sound dull.

 

In sealed boxes, a bigger sub usually gives a better roll-off point and sometimes QTC than their smaller counterparts.

If you're worried about not hitting 20Hz as audibly as the rest of the frequencies than port/tune to 25Hz (so that 20Hz is close to -12dB), it'd be the same as a sealed boxes FC being QTC .707 with roll-off at 30Hz, which is rare if you don't have an LMS motor or a very low FS, so porting that low could be better than sealed as per response. A lot of mainstream brands offer specs like these, the Type-R 15 and 13.5W7 model to around FC @ 30-35Hz in a medium sized sealed box, which is great.

Why does Fi offer a "high-Q" option and not low-Q?

You might not need mids to keep up if the QTC is low and the sub already dropped off when it gets to where the comps are crossed at.

The raw sound is another story -_-.

If you don't think it's faster than 10's, couldn't you just throw more power at it? Does that make the cone move faster? I guess it would make it move farther too, not really helping.

 

Once again, Dukk and I are on the exact same page.

If I had my way, I would have a 15" sitting in the middle of my dash!

 

like to hear this cause in most sq installs i see, its mostly 12's or 10's. Another thing is the box doesn't have to be sealed to be considered a sq set up either, does it? I use to have my subs in a sealed box and now they're in a ported box tuned to 30hz and i like the way the ported box sounds better. Does anyone use ported enclosures in sq set ups?

 

I used sealed, why? it's easier, it's smaller, power is cheap and it is more versatile.

For subs, my SQ/Daily setup only play 31.5 down, my windows down fun setup play from 31.5 to 100...

Yes you can have a ported box for SQ, but then you would need to have removable ports like i was planning to do and gave up. One for SQ tune very low and small port, one for daily tune a little higher with a good port size and one for SPL match to gain the max of the setup. All this to get the best of the box at different listening level.

 

With ported enclosures though sometimes it's harder to get your midbass blending since you start to have group delay issues between the cone and port. In a car unfortunately it's all about comprimise and trade-offs.

 

Many people have successfully ran vented boxes for SQ. You don't need interchangeable ports and group delay can be managed during the design stage.

Yes they are a little more involved to design and build but well worth it IMO.