Toyota Supra: Upgrade


Toyota Supra: Upgrade

Toyota Supra… here she is!

The latest Toyota Supra is a stunner. It really is a fabulous looking car. As you may know, it is based on the BMW Z4 and while a great platform it does mean unfortunately it has inherited the BMW audio system. That’s a big let-down!

Fortunately, we have a tried and tested solution for the BMW and this can be adapted to suit the Supra.

Supra Project

The owner of the car in this project wanted an accurate and powerful sound that would fit without alterations to the trim. That would mean changing all the stock speakers and amplifiers with a subwoofer to handle the bass.

The standard amplifier is pretty poor in my opinion and needs changing; the only complication here is that the audio runs on a fibre optic MOST network. Fortunately, we have an interface for this that allows retention of all the vehicle chimes, announcements and warnings as well as supplying a clean digital output of the audio stream.

For amplification, we opted for the stunning Audison Forza8.9Bit and AP1D pair. These both fitted in the space vacated by the Toyota amplifier.

The speaker sets we used are from the Audison BMW specific range. There are component sets in the front doors and rear panels behind the driver and passenger seats. 

These require a little work to create a perfect fit but nothing untoward. We naturally installed sound deadening to the door panels both inside and out to create the best acoustic space possible.

Although not shown here, we also applied sound deadening around the rear speaker mounts.

The original bass speakers are mounted in a slim box behind the front seats and these were also swapped for Audison units. The space below the bass units and the whole boot floor was also treated with sound deadening.

Subwoofer Installation

The main challenge in this car was to get a useful subwoofer in without taking up the (limited) boot space. The stock car comes with two 8-inch drivers placed behind the front seats but these can in no way be considered subs; they are the bass component of the 3 inch main speakers.

I have seen online posts of owners introducing ports in the trim to try and improve the bass response, but that is not really going to improve matters. No, we had to get a ‘proper’ subwoofer into the car and I opted to manufacture a custom glass fibre enclosure that would mount in the N/S boot recess. There was only room for an 8-inch unit so I chose the Audison dual coil Prima sub.

This powerful driver is optimised for a small enclosure so is ideal for this application. Even so, space would be tight so I had to ensure I used every available bit of volume.

The first step is to mask off the trim piece.

Glass fibre and resin are then built up inside to make sure I get all the available space. An MDF board is then bonded to the front and side to complete the box. 

I also line the inside of the enclosure with Dynamat to further enhance the stability of the fibreglass.

Once trimmed and installed the fit is perfect and can be removed easily if needs be.

I also refitted the tie-down loop that was under the enclosure.

Final Steps

The final part of the installation was the DRC. This elegant unit allows the user to control the subwoofer level and access different equaliser pre-sets that I program.

This is mounted discreetly under the HVAC controls.

With everything installed it was time to tune the sound. As you may have read in my other install blogs; my preference is to tune for a clear and detailed sound stage right across the dashboard. I knew there would be particular challenges in the Supra as all the bass frequencies are mounted behind the driver and I did not want these dragging the stage backwards. 

To compound this, the closest high-frequency speaker is also behind the seats with the driver’s side one only 20cm from your ear!

Fortunately, the Forza amplifier has a very powerful digital signal processor on board which gives me access to frequency, cross over points, time delay and phase. With careful manipulation of these parameters, I achieved a stunning result. The image is very definitely in front of you but with an immersive feel and a huge warmth and punch. 

This system was not designed to rattle the windows (although it will!) but rather to deliver an accurate and detailed musical experience at all listening levels; I think I achieved that in this stunning Supra.

If you would like to know more about how I can improve the music in your life, please give me a call on 01625 432707 or have a look at my contact page for more details.

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