05/04/2026
Hi Everyone,
Long time no see! In the last few months, we worked on a few Dolby cars that I could not post build logs of immediately, and also some more simple projects for change that we donât usually do articles on. Plus I have been skiing a lot đ
But with the arrival of the end of ski season and more traditional projects , we are back to the old posting schedule.
First up in a car we have not worked on before, a 2025 Lexus NX350 F-sport. We had delayed this project for a while in the hopes that the Mobridge Lexus integration module would release, but in the end, decided to do a initial version with a secondary streaming signal source in addition to the stock Mark Levinson amp out, for now, prewired for the Mobridge module, so that when it releases, the car can come back and we simply swap in the module it do a subtle tune adjustment and be done.
I performed most of the work on this vehicle while Jesse did the underhood fuse holder.
The goal for this project is to substantially increase the sound quality from the stock ML system and be able to achieve a fair amount of low end at the same time. We wanted to retain the OEM locations for the car as they are too bad for our purposes. The customer wanted a full stealth look in the back with everything in the floor, in place of the stock plastic and foam trays that hold up the floor panels. These cars, like many new vehicles, do NOT come with a spare tire anymore.
The signal, as mentioned above, is a dual source system for now, with the stock oem post amp summed as one, and a Mosconi AMAS-LD4C high quality streaming module as the other. The AMAS sends an optical signal to the DSP directly and will eventually be replaced by the Mobridge module.
For amplification and DSP, we chose an Arc Audio Falcon 12 channel DSP amp with a built in 16 Channels of DSP, this amp powers the front 3 way with 75 watts on the midrange and tweeter, about 110 watts on the 3ohm midbass, and 75 watts on the rear oem speakers and center channel, additionally, it sends 200 watts to a front impact subwoofer to firmly anchor the bass note upfront. Using its DSP controlled RCA outputs, the signal goes to two Nighthawk amps, each powering a subwoofer with 800 watts RMS.
Whatâs really cool about these amps is that they can internally distribute the power to the channels needing them. meaning that despite a common RMS rating, what you end up getting is more power on the midbass and impact woofers, the two high power requirement drivers, and a little less on the other speakers that demand less. Thus these are amps, from experience, that always sounds more dynamic and cleaner at higher volumes than their ratings suggest.
For the front stage, we went with a set of the newly redesigned Gladen Pro 3 way components. These take over from the Gladen Aerospace set that has long been my favorite out of the box 3 way set, which has since gone up substantially in price.
We made 3D printed adapters for the midrange to go into upper door location, while the tweeter went into the stock top of the dash location. It is interesting to note that in the ML system, both of these locations are occupied by the same 3.5â coaxial and both are fed their own virtually identical signal. Very odd to say the least.
The Gladen Pro midbass went into the stock lower door location via a Metra adapter, and the entire door and door card was sound proofed with CLD damper.
As mentioned above, the OEM rear top of the door and center channel speakers were retained, and I used an integration harness to get the signal in and speaker wire out from the stock amp located in the center console. I also installed an LC-1 line level attenuator in the storage tray to act as master subbass control.
For the impact woofer, we used a Helix Ci5-F200 8â woofer, chosen for its super shallow mounting depth. It is located in a very small enclosure that took away less than 3âs of overall leg room. From past experience, I cut an open slot in the back for the enclosure to vent into the floor cavity below, as to prevent too much midbass build up that we simply have to tune down later. This worked out really well in this car.
The impact enclosure has a simple magnetic front grille that hides and protects the driver. Not meant to be showy, simply hidden.
For the subs, we had an abundant amount of room so we went with a pair of Wavtech Thinpro 12s, each run off a Nighthawk.
The main challenge for this fake floor build is that unlike previous generation SUVs, these newer vehicles no longer have a steel floor with a spare tire well. Instead, it is a low floor panel with a top layer propped up on plastic bins. While this gives us more room to play with, it also means more care has to be taken to properly support any floor pieces that will remain in the car.
After a lot of test fitment and mock ups, I came up with a design that uses all stock mounting points for the physical location of the structure. The only hole drilled is for the master grounding point on the floor, as all the OEM grounding points were deemed to be too far away or inadequate.
I installed a series of studs into existing mounting holes on the floor braces to allow me to bolt down a foundational mounting structure upfront. This anchors the amp rack and also spaces it up to the appropriate height and orientation.
I then built a 1.3 cubic foot sealed enclosure using the space in the back half of the hatch and into the mini well that is in the floor. This structure bolts using two existing holes and also locks into the amp rack foundational board upfront, creating a solid structure with zero additional holes drilled.
The amps and subs are wired up and installed and the design features a dual layer trim, with a 3/4 inch chamfered trim above the equipment wrapped in white vinyl, and another layer of 1/2" roundover trim on top wrapped in graphite vinyl, mimicking the interior and exterior color of the vehicle. These trim pieces and a block on the subbox, supports and sandwiches the side oem floor pieces so they remain secure and strong, as they previously clipped into the plastic bins that is on the floor pan.
Above that, I built a new top floor panel, wrapped in black carpet, and then dyed it slightly lighter to match the oem carpet. Then built a breathable grille with some strips of mdf for support and a 3D printed Lexus logo to set it up. The oem cargo mat goes on top without any issue. The end result is a 100 percent oem look when the carpet mat is in place.
From first power up, I knew this car on the AMAS signal (soon to be the ONLY signal once the Mobridge module releases) is going to be great. After some tuning with mike, it really sounded great.
The imaging and staging on this car is ROCK SOLID, with a very well defined center that does not move at all with various types of music and vocals, helped perhaps by the center channel utilization. Depth, height, and width is all well above average, going beyond the pillar in some cases, and about 8 inches off the dash and at the edge of the windshield.
Tonally, itâs very well balanced. This Helix impact woofer is a very good driver for this purpose, adding solid midbass reinforcement without coloring the midbass frequencies. It is less powerful than the Audiofrog GS8ND2 that we have used before, but it is more transparent also saves us almost 2 inches of leg room due to no hanging magnet, which in this car was very much appreciated. Midrange and highs, with this being the first time we are using the new Gladen Pros, sounded just like the Aerospace set I remember. It is extremely detailed yet not harsh, with very good resolution and conveys a great sense of space. I truly find no fault in this front stage and I would be happy to listen to it forever, at any volume.
The two big Wavtech Thinpro12s, in their preferred tiny 0.65 cubic foot box each, does an incredible job of produce smooth bass at a very high volume and goes extremely low. I would say it is flat all the way down to 20hz easily in this car yet can blend superbly well with subtle music and bass instruments, again, assisted by the front impact woofer.
This is just an overall very very good sounding car for all types of music; I spent hours listening to it during and after the tuning process and nothing I threw at it seems to phase it.
Canât wait to get the Mobridge piece in once itâs available to complete the project fully!
Thanks for reading and as usual, please refer to the individual pictures for more detailed information.
Cheers,
Bing
