I installed this a few weeks ago and revised it last weekend when we finally got a day where it wasn't -40 outside.
The TL;DR: Great sub at a very reasonable price point. I highly recommend it if you want some extra bass without taking up a lot of space.
The long version:
I have absolutely no audio experience and am a novice overall with car stuff (panels, wiring, etc.). Thank you to the people on this forum who contributed, allowing me to give this a try. I struggled more than most will because of my lack of experience.
I have a Model 3 LR so this was a lot easier for me than for the people with SR models. Overall, I spent about 8 hours on day 1 to get everything in and working. I was out of time that day so I copied settings previously posted on here. I spent another 3 hours last weekend using a voltmeter to set the LOC and amp up properly. It took me a lot of time, but I could see it being a 3-4 hour job to install/tune for someone with experience. I turned the bass knob to max, set the LOC to output 5V at 75% volume on my 50Hz/-5dB test tone then adjusted my amp to be at 25.2V. The major difference is that after using the voltmeter, I had to increase the BassX a lot more. My output on the LOC also didn't cause the maximized light to go on with the test tone (which is how I set it up the first time). Overall I think the sub sounds a bit cleaner and less boomy now. The settings posted by others on here are excellent though and if you don't want to spend the time using a voltmeter, they'll do the job no problem.
My major struggles:
1) The fricken jack nut. There are not enough expletives in the world to describe this thing. I thought I'd be smart, use a smaller drill bit and take my time. I spent about 30 min making the hole a tiny bit larger and retesting. Once the base of the jack nut fit into the hole, I figured I could jam it in with a bit of force and it would stay in properly that way. Don't be an idiot like me...the jack nut ended up deforming so badly that I wasted another 30 min with needle nose pliers trying to make it useable. In the end I made the hole larger, put the jack nut through and superglued it to the frame so that it wouldn't spin. I had to use my power drill to get the bolt into the jack nut because I couldn't fix it up perfectly with the pliers.
2) Positioning the sub properly. I rotated the clip to get the hole to line up, but I couldn't get the sub to fit properly. It wasn't good enough to get the jack nut and upper plastic trunk liner on so I had to leave those out until I got time to fix it up last weekend. I took all of the trunk liners out and re-did the positioning, that seemed to do the job. I think the first time my liner shifted a bit so the sub was hindered from sitting in there properly. I still have a small gap so it's not perfect, but I was able to get the jack nut and my upper trunk plastic liner in so I'm happy for now.
3) The rear back seat pillar that I removed was really tough for me to get back on. I suspect someone with car experience can do this in 30 seconds, but it took me a good 45 min the first time and another 10 the second time. In hindsight, I wonder if it's way easier to put in before you put the rear seats back in, maybe that was my problem. Using excessive force on this is completely unnecessary...I got frustrated and was pounding a bit with my fist, that didn't help. When the clips are lined up, it'll go in with very little force. The second time, I tried to line up the large upper white clip first, then the bottom and it went a lot better for me.
The wiring for the audio was much easier than I expected. Posi-taps are a cheat code for novices like me. I used 4 blue and 2 yellow. I had the older wiring from NVX with the blue/dark gray speaker wire. The dark gray is perfectly rounded and fit in the blue posi-taps better for me than the blue, so I used all gray for the 4 harness wires and the blue for ground/power. I tapped into the harness before it goes into the amp rather than at the sub as there's more space to work with this way. The LOC is resting underneath the factory amp and is going nowhere. The NVX amp is velcroed to the frame behind that rear seat pillar that I struggled with. I grounded my NVX amp to the same spot as the factory amp.
If I was to do this all over again, I'd just put the NVX amp and the LOC under the factory amp, velcroed to the frame if necessary. There is plenty of room. I was overcautious and cut my wires so long that I can't squish it all in now unless I cut and revise all of the wire, which I don't have the time for now. The power cable for the NVX amp is easily long enough to reach the penthouse even if the amp is mounted in the back.
One tip that I didn't see mentioned...before you remove the rubber seal on the bottom of the trunk in order to get the plastic liner back in properly, put some cheap masking tape (the dollarama stuff is perfect) on the bumper of your car. The glue from the rubber seal is very sticky and is easy to get on your car.
I'm really happy with the sub, it's exactly what I wanted. I'm old now and listen at fairly low volumes (20% mostly), so I like having the BassX cranked up to get good bass. Mine's around 75% I believe. There's no need to put the BassX up that high when the volume is turned up. If I throw on In the Ayer by Flo Rida and go up to 50% volume, my rear view mirror will vibrate. I used double sided mounting tape to put the bass knob for the LOC by my driver seat controls so I can adjust the bass. I have to turn the knob down a bit if I turn up the volume or it'll give me a nasty headache. I didn't bother with the bass knob that came with the amp.
With the new update, I tried setting the sub volume to max and using the factory sub. It's woefully inadequate for me without the NVX sub now. I wired the NVX out of phase and left the factory sub connected, though it's difficult for me to even notice it at the low volumes I listen at.
