Gransport Audio Upgrade – Part 1

One of the biggest complaints of the 4200 is the quality (or lack thereof) the factory sound system.

Maserati offered a “upgraded” Auditorium 200 system (code: A200) as a option on the Spyer/Coupes and included it standard with the Gransport. It consisted of better speakers (apparently no longer paper coned) and a external amplifier. The standard head unit (Becker Infotainment in the GS) also is a poor performer by today’s standards. Although I’m not aiming for anything near Audiophile quality, a substantial upgrade seems easy enough to do.

I wanted at the very least Bluetooth pairing. There are options to replace the CD player inputs on the Becker with a low cost ($20) Bluetooth adapter. Although I’m sure these would work, I suspect the audio quality would still leave a lot to be desired.

I decided that I would replace the built in head-unit with something a bit more modern. In my case, I went with a Pioneer SPH-10BT. This gives me a somewhat easy option for navigation (and of course Bluetooth).

Bigger than this is that there is no single DIN unit I’ve found that wouldn’t massively obstruct the controls (HVAC) above the head unit in the dash just because of the way things are laid out. The SPH-10BT also give me a way to mount my phone (which I needed anyways), but sits compact and fully controllable without a smartphone attached. When I need to use navigation, I can pop my phone in and it’s small enough to not obstruct much.

The head unit itself is pretty low cost at under $200. Since it has a built-in 4x50W amplifier, I figured it would be better than the Auditorium unit already installed in the car.

Bypassing The Auditorium Amplifier

The amplifier is located in the trunk of the car behind the battery ON THE COUPE. On the SPYDER, it’s located on the left side of car in-front of the CD changer, however Maserati went with a different design in that the entire trunk harness is different for those with the amp, and those without. Unfortunately, this means there is NO EASY bypass method for these cars.

The first step to accessing it is to remove some of the surround in the trunk itself. I suspect removing the battery may be all that’s needed, but I removed more in order to get a better look and find the cables needed to do the bypass.

Truck Ready to Pull Apart

The first step is to remove the plastic surround at the rear of the trunk. It’s held on by 6 simple screws. Once removed, the piece should come off easily. If not, you likely missed a screw so double check carefully.

Inner trunk Liner

Next is to remove the inner trunk liner. There’s nothing holding this in and so you just need to find a corner to lift and slowly but surely pull the whole thing. You may need to bend/squeeze it a bit to remove it.

Side liner Clips

Now that the inner liner is out, it will expose two plastic clips that hold the side panel into the trunk. Use a tool to pry both of these upwards (they aren’t screws/twist type/etc).

Side Panel Removal

Now remove the side panel. It isn’t held in with anything else other than a bit of Velcro and the fact its tucked under other panels/etc. You need to be a bit forceful again to pull it out but it should just pop free.

With the side panel removed, there’s a lot of access now to everything. Since the amplifier lives behind the battery, I removed the battery to get a better look. Now would be a good time to shut down power to the car as well using the shutoff switch.

Battery Removal

The battery hold down is simply a 13mm bolt so loosen that completely. Also disconnect the negative terminal on the battery using a 10mm wrench. There is no need to remove the positive terminal as all we are doing is rotating the battery out of the way. Once the battery is out of the way, you should see the amplifier (a silver metal box with heatsink fins on it).

Image result for ask hi-fi vhp series
The Amplifier

The next part is to try and follow the wiring harness coming out the back of the amplifier. It should be on the side facing the rear tail lights. If you follow that cable to the area on the LEFT of where the battery goes you should find it terminates at two large connectors.

The Main Connectors

The way that Maserati designed this is so that the amplifier could easily be installed by the dealer as a option. As a result, there is a short 12″ adapter cable that plugs into one end the amplifier, and the other end these two connectors. This places the amplifier in series with the system. To bypass, or remove the amplifier, we simply need to remove this adapter cable and connect the two ends of the main wiring harness back together.

The cable itself may also have a label on it indicating the Maserati part number (200647) which can help you identify you have the right cables.

Picture 2 of 2
The adapter harness (200647)

To disconnect the connectors, you need to follow two steps.

Step one to disconnecting the cables is to release the lock. This is the small grey plastic piece. Gently push it outwards.

Then, using a small screwdriver push the black clip under this shield up gently. At this point, it should be easy to pull the connectors apart. Then when you need to reconnect them, simply press together and then press the grey lock back inwards.

At this point you’re pretty much done bypassing the amplifier. I left the amplifier and the adapter harness in the car as is (just tuck the wires away). This will allow me to later on easily return the system back to stock.

As a note, the adapter harness is available as a separate part fairly cheaply. This would make a ideal adapter should you want to install an aftermarket amplifier without having to modify/permanently change the factory wiring.

With the amplifier disconnected, you can now reverse the process. Start by reattaching the battery and connecting the negative terminal. As sanity, at this point I turned the main power back onto the car and verified that audio still worked.

It did, and to my surprise I felt that even with the stock head unit, the audio quality seemed actually better WITHOUT the external amplifier in the path. I’ve read that the amplifier sits at a THD of around 10-15% so this doesn’t surprise me too much. The Becker headunit likely has a better amp built in! At the very least, get a upgraded stereo by removing some of the components.

Putting everything else back in is fairly straightforward. I had some difficulty with re-installing the side panel in the trunk. To make this easier, I just pulled off the trunk weather stripping, put the panel in and then carefully pushed the weatherstripping back in place.

Remove weather stripping

At this point, we’ve bypassed the amplifier. This would be a helpful step for those who have had their amplifier fail as well. It’s definiately not worth the cost, even for a used unit to replace it in my opinion, so you might as well just bypass at that point.

In the next section we will be installing the actual new head-unit along with making a plug and play harness for it.

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