08/23/2026
Besides sound quality and installation integrity, one thing I pride myself on is keeping things stealth and retaining as much daily usability as possible for a daily driver. Even when the design calls for some decent sized subwoofers and the accompanying enclosure, I try my best to retain as much room as possible.
This 2019 Lexus GX460 from a previous client, is perhaps one of the more extreme exercises in this regard in recent memory.
The customer takes this vehicles on mild overlanding and camping trips frequently, and since he does not need the third row seating, he wanted us to remove it wholesale and replace it with a system with decent amount of power and output that matches his previous build. But at the same time, there was a strict requirement that behind the structures we put in, a full folding stroller must be able to fit, additionally, the oem cargo cover, which actually sits quite low above the oem loading floor, should be kept if at all possible. Finally, he wanted us to build some storage space in any room we had left after the 3rd removal and audio components. For the rest of the car, he wanted to add carplay into the mix, and a front camera, while keeping the rest of the interior as OEM looking as possible.
The original design called for a rear facing enclosure with the amps integrated on the backside between the subbox and the 2nd row seats, which according to my calculations, would JUST barely allow the stroller to fit based on his measurements. But, as the install progressed, I figured out a way to gain an extra 4 inches or so of depth at the cost of having to squeeze a lot of components and wiring into a tight space…which lead to some pretty complicated wiring lol, but such is the norm with me I guess. One final requirement for this build was a secondary, isolated battery in the back so that he can run the audio and maybe some other accessories, without ever needing to worry about being stuck in the wilderness with a dead starting battery.
I performed all of the work on this car.
For the signal, being that it’s a late model Lexus, is a two fold affair. The OEM amp signal is summed and processed by the DSP, while a Mosconi MOS BTS LD4C high quality streaming dongle acts as a secondary, pure signal source.
I chose the ZZ2 GX460 carplay/AA kit and integrated it behind the stock headunit, being that this car has a stock touch screen, it made navigation through the menus quite easy. The ZZ2 also allows the input of additional cameras, so a simple license plate frame mount on the front bumper gave him forward video ability. The Front camera can be triggered off reverse gear, or the car’s built in radar proximity sensors, which I felt was a pretty cool touch.
For the front stage, we went with speakers that I know will fit great in the stock locations while providing excellent sound quality, The Gladen Pro 6.5” midbass and 2.75” midrange was installed into the stock door and dash location using Metra and 3D printed adapters, while an Audiofrog GB10OE went seamlessly into the stock tweeter location like it was designed to do.
The OEM rear door speakers were in good shape and retained as rear fill.
For processing and amplification, we went with a Mosconi ONE 6/10 DSP, this takes the stock front and rear amp signal, sums and processes them and then controls the entire system with its 6 built in channels and 4 external RCA channels. The mid and tweet receives 100 watts RMS a piece, while the 2ohm midbass gets 120 watts. A Musway P2 mini amp was used to provide rear fill on the stock speakers, while a Mosconi ONE 1/1000 sends a kilowatt RMS to the subs.
For sub duty, we wanted something that provides adequate bass in a tidy, most importantly, shallow package, without being too cost prohibit or power hungry. So a tried and true solution of two Arc Audio A12s provided the bottom end, working off 500 watts a piece.
Onto the design of the back, as mentioned before, after the 3rd row removal and measurements, I realized that if I put the two main amps UNDER the sub enclosure instead of behind it, I could gain about 4 inches of depth across the entire hatch, this meant however, that’s all the other components, the battery, the isolator, the mini amp, and all wiring and distribution would need to be installed in between the two subs, this was a tight squeeze but was I was fairly confident on my ability to squeeze wiring and componentry.
A foundational structure was bolted to the stock bare floor, with various spacers so that the front and the back sat at a consistent pitch (they were 7 degrees off from the factory). Then the amp rack was built that houses the two Mosconi amps, with openings cut to allow the fan to circulate air around. This amp rack also acts as the spacer for the enclosure, which is an odd looking one with appears to be a normal trapezoid single enclosure from the front, but in the back, there is a space in between the two separate boxes that houses all the aforementioned stuff. It also sits right below the cargo cover so that it can be retained fully to hidden everything.
This was one of the more backbreaking wiring jobs I have done recently, hunched over sitting on the folded down second row for about 2 days straight, but I got it all done and also wired in an additional protected 8 awg extension on an Andersen plug, to give him the ability to plug in external accessories running off the rear battery. A smart isolator ensure that the front and rear battery decouples once the car is switched off, but charges when the engine is running.
With the remaining space behind the enclosure structure, I built a simple carpeted tray with a divider to allow him to stow camping things under the floor, a new main loading floor panel was fabricated that sits on top of the tray via pin dowels. As the original floor was basically the seat backs of the 3rd row.
It is quite simple to look at when it’s done but perhaps one of the more intense design processes I have gone through, trying to obtain as much usable space as possible without sacrificing sound performance.
From the very first time I powered on the system, I knew it should sound quite good as it was already natural and decent without any EQ. After a few tuning sessions, we got it dialed down quite well. One interesting thing to note is that this base model sound system, not the mark Levinson, had a much better stock signal than the ML to work with. It is both flatter, and devoid of too much all pass filters and delay that makes the stock ML signal so bad to use. In fact, after some tweaking, I found that besides sub 40hz bass, where the stock signal rolls off gently (there is no stock sub in the base system), the oem signal sounded as good as I have heard on any car in recent memory. The direct streaming dongle sound better, but not by a lot, and even less so when driving down the road with all the ambient noise. The only truly noticeable part is playing heavy bass music with a lot of subsonic components; this is when you can tell the stock signal does go quite as lo.
Staging wise, despite not using the OEM center channel, the center image is rock solid above where the center channel grille is. Width is pillar to pillar and depth is superb. Height is about 6 inches above the dash. As good as I have seen oem locations do.
Tonally, with the component used, the strong points on the car is midbass snap impact and extension. All of the higher end gladen speakers I feel excels at this, just effortless impact and blends great both with the subbass and the midrange. The Gladen 70 midrange, which I have frequently used as a widebander, has a great amount of resolution and though we had to tame some windshield reflections on the eq, it was pretty good once dialed in. the stock tweeter location actually puts the driver semi on axis, and the GB10 did a great job here, never offensive and supremely airy and detailed.
The two A12s did what they are designed to do, to be a great all around sub while not taking up a ton of power or space. They effortlessly went down into the subsonic on the streaming source, giving the large interior a good bit of shaking, but are very clean and fast as to never make their locations known. It is the reason they are our number 1 used subwoofer currently, while they aren’t spectacular in any regard, they are really really good in virtually all facets, while at a very reasonable size and price point.
This should be quite a nice vehicle to take on long camping trips now.
Thanks for reading, and as usual, please refer to the individual pictures for more detailed info.
Cheers,
Bing
