I just realized my 2019 lariat with the B&O sound system has a rear sub!looks to be an 8 inch.can it be changed to something different to maybe put out a little more bass?

 

Yes of course. Any thing can be changed/updated/upgraded. Just depends on what you want and how much money you want to spend.
Kicker makes a drop in sub/amp combo that gets great reviews but is pricey in my opinion running around $600 last time I checked. Others put subs on the floor under the seat so if you don't use the cargo area under the seats that is an easy way to go. Others add subs behind the seats and what not. Lots of options just depends on what you want, want to invest and are willing to give up.
The kicker system is appealing to me since you don't lose any space. The price isn't though. Lol.
In my 18 the only bass I get is from the front door speakers. I don't detect anything coming from the rear when riding back there on top of the sub. It's woefully underpowered for sure. May be able to add power in line to it to help with that? Would be worth checking into.

 

I think people have said you can put some insulation in the sub box to help it along a bit but I would be interested to see if there is another efficient sub that could be swapped out for a little more output without breaking the bank.

 

Here is what I did on a 2006 Explorer and a 2005 F-150, both with the factory 8" sub and amplifier: Add a shallow-mount 8" subwoofer, a 300 RMS W amp, and dedicated 4-8 gauge power wire to the amp. $100 for the sub, $100 for the amp, and $50 for the amp wiring kit. Those prices are old, so figure $300 for the job.

Disclaimer: adding bass isn't for kids wanting to thump up and down the block. Solid bass will make every type of music sound more full, more complete ... just a lot better. Country, classic rock, whatever.

Use a factory wiring diagram or other online resources to locate your factory signals at the amplifier. There will be a 5 VDC turn-on, speaker signals, 12 VDC constant power to the amp, and ground. All of these will be used. But, we're not going to use the factory power wire to power the new amp. The speaker/bass signal may be line level or speaker level. On my older vehicles, they were actually line level, which was nice.

The biggest complication is the 5 VDC non-standard voltage Ford uses for the turn-on signal. Every amp in the world is going to look for a 12 VDC signal to turn itself on. So, you need a special relay that uses the factory 5 VDC signal and the 12 VDC constant power signal as the output to the amp. PAC makes one called the TR-4 (but mine was defective, never stopped power, and killed my battery) and NXT (I think) makes one, too. This re-purposes the factory 12 VDC constant power to the factory amp as the turn-on/trigger signal to the aftermarket amp ... using the factory 5 VDC turn-on signal as the gate to this specialized relay.

Buy a bag of Polyfil at Walmart in the arts and crafts section ... it's just polyester filling material for decorative pillows, stuffed animals, etc. It's good batting to improve the sound dynamics of the sub enclosure.

Usually, the factory amp is so small that it's not worth removing ... it's doesn't free up any space that you can subsequently use. So, I leave it physically in place, but it's not connected to anything. Remove the factory sub enclosure. Remove the factory sub from that enclosure. Fill it up with the polyfill. Add your new 8" shallow mount sub. I use silicone sealant for any factory holes and for the screws to mount the new sub. Reinstall.

Obviously, running wire from the battery to your amp is going to take some time. I like to route my wires under carpet and under panels for a clean look.

My F-150, I used the Kicker CompRT sub mated with a Kicker CX300 amp (my links to Crutchfield get re-routed to Walmart -- buy where you want, but you'll get better info at Crutchfield). Just fills out the sound amazingly well and can hit hard if you're into that, too. Obviously, won't be winning any sound competitions doing this, but the difference is night and day.

I have other projects ahead of this on my list, but I will eventually do this in my SD. 2020 or 2021 project.

 

Thanks for the replies,I just wonder what a kicker sub in the factory box would sound like?

 

I picked up a rockford sub of amazon to try to see if it got a little more thump. The hole for the ford factory sub isn't standard size. so i had to dremel the hole 1/4" bigger. the factory sub has a mount bolt in the center of the magnet. had to seal that up. the box has an indent for said bolt. that hits the magnet of the new sub. had to heat gun and massage that indent out to clear the sub. then filled with polyfill. was WAY more work than i expected. was hoping for a simple swap. In the end it sounded worse if any different at all. the stock amp just doesn't have any power to drive anything more than whats there. In the end i added a polk 5000.5 amp to power Infinity door speakers and this sub behind the rear seat. The bass is decent. a big improvement from stock.


EDIT: I just realized you have the B&O. all of the above was on my 2018 platinum with the Sony system.

 

I talked to my stereo guy today,and he wants to put a single 10 inch under the back seat with a kicker amp.but I’m wondering if 2 wouldn’t be better.

 

i put 2 jl audio micro subs behind the rear seat in my truck. kinda pricey but sounds amazing

 

several good threads on this. if you want more bass buck up and do it right. simply swapping the sub is a waist of money without sending more power to it