Pre planning adding powered underseat subwoofer

I just had an 4 channel amp installed in my 4runner after upgrading my speakers. I went to a car stereo place as I was not confident enough to trybsnd pull out my head unit for access. I was wondering if I could tap into the amp connections to add a powered subwoofer using rca y connectors and power distribution block to connect to the 12v line they ran. I watched some YouTube videos that say this should be fine. Thanks.

 

What I’m reading here is that you replaced speakers, it didn’t satisfy and you got sold a 4 channel amp and nobody thought to prepare for the next step, which is add a sub and you’re trying to salvage it with Y connectors and like a $200 “subwoofer” because this whole time your priority has been budget.

Say so if I’m way off but that’s what it’s looking like, and I don’t blame someone wanting to spiff up their shitty Toyota sound system because that’s what they are famous for, being shitty.

Here’s what’s going to happen with a powered sub under the seat. It’s going to be annoying because there is a vent under your seat and very limited height/space, so whatever you find that fits is going to be underwhelming and you’ll spend a week or two pretending like it’s good enough because you’re so far down this wrong path already that it’s hard to admit you kind of want to start over and the money you’ve spent so far wasn’t really well spent. I’ve never met a compact powered subwoofer that size that can do any/much more than what the 6x9 speakers in the front door already do. Odds are you’ll overdrive it and it will fail.

My advice is to think more about the whole system, what your expectations really are, and consider taking a break to think about a real solution that will definitely meet your goal. You’ll need to know that whatever you add can keep up with whatever you already have.

So what are some possible solutions here? If I was where you are, first I’d be looking for a subwoofer that I KNOW will do the job I want it to do. That means figuring out size, power handling, placement and cabinet. Once I nail that down I’d find the subwoofer amplifier I want to use with it to accomplish this.

Once you are set on that stuff you need to figure out what you want to do for signal. You could replace your current amplifier with something that has RCA pass through outputs. You could replace your current amplifier with a 5 channel amplifier. You could use a DSP for signal routing to your current amplifier as well as the additional mono amplifier.

It’s not a good idea to split the signal for your subwoofer and door speakers because you should high pass the door speakers when adding a subwoofer.

There are a lot of other factors to consider, but you didn’t say what radio you are using, what speakers you installed, or what amplifier you bought, or what size power wire you have so directly answering your question about running power requires more information.

 

Actually I am pretty happy with my setup right now. The combination I have is pretty good. It's more that I'm toying with upgrade ideas since I've started. I'm likeca kid with a new toy. I replaced all my stock speakers with memphis audio ones. Component 6x9's with tweeters up front and 6.5 coaxials for the rest. I even put baffles all around when I saw how easy water gets in the doors. The bass seems ok but I was just considering a way to add a sub without having to pay for installation again. I figured the underseat options may make it easy without taking up much space. Looks like there are plenty of options from good brands. Long ago I had a system with 2 bazookas along with Boston acoustics components all around. That system cranked.

 

It’s good to see you have something to work with but to answer your original question I still need to know what power wire you have, what amp you have, and what sub you are considering.

I still recommend not splitting signal and you should consider a different solution.

 

I have mephis audio PRX690C up front and 2 pairs of PRX602 speakers in the rear doors. I just had an alpine BBX-F1200 amp installed. 4 channels 50w rms. The weather has been crappy so I am not sure of the gauge of the power wire installed. I plan to take a closer look and take some pictures. I have looked up jbl, mb quart and Blaupunkt subwoofer options a bit. I see a few from Rockville that seem popular but don't know much about them. I see memphis audio also offers a version. Say my power wire is 4 gauge (I assume from reading). Is it too much power with the added amp to expect to push through the wire or is it necessary to run another line to the battery?

 

280W RMS @4 ohms means you would have the ability to add a subwoofer that does around 500W if they ran 4AWG, but if they ran 8AWG (probably did) you’ll need to add a run to power an additional subwoofer amplifier.

Knowing if you have CCA or OFC would make a difference as well. Generally you should upsize for CCA.

I also see that this amplifier does not have speaker level inputs so you either have an aftermarket stereo or they installed some kind of line output converter. Knowing what you have would help resolve the signal issue.