The iconic Porsche 911 has been around since the 1960s. Since then, it’s remained faithful to the original design ethos and is still instantly recognisable. It’s a great car that’s at home both crossing Europe on the Grande Tour or popping down the road on the daily commute (remember those?).
The 997 variant appeared in 2004 and the technology in the entertainment system was, for its time, pretty sophisticated. However, with no DAB radio, no Bluetooth and very basic disc-based navigation, it’s now quite dated. In addition, the Bose audio is also lacking in detail and any real presence.
Time to bring this classic up to date!
Here at Car and Home Stereo we always strive to make sure any changes to the vehicle are done sympathetically. It’s important to us that the finished article looks as close a possible to a factory option. Therefore, installation parts must be as good as the car manufacturer would use to ensure a perfect fit and finish. Also, we ensure that any changes made can be reversed to return the car to its original condition.
The first job is to change the dated PCM2.1 head unit to a modern entertainment device. Fortunately, there’s plenty of space in the radio aperture. But as you can see, there are lots of cables that we won’t reuse and the space is hard plastic.
Every end is secured and wrapped in cloth tape to prevent rattles, along with the new cables I introduced. Correct cable routing is also crucial to making sure everything fits without interfering with any of the vehicle systems. The finished article is solid with a perfect colour match.
We now have DAB radio, Bluetooth, CarPlay and Android Auto for complete smartphone connectivity all controlled from a bright and clear touchscreen. All the original steering controls continue to work as normal, giving hands-free, volume and other functions.
Now to make it sound amazing!
The speaker locations in this Porsche are excellent, with a tweeter on the dash corner and a mid and woofer in the front door. There’s a pair of small speakers in the rear and a centre channel speaker in the middle of the dash. However, if you’ve read my past blogs you’ll know what I think of centre speakers!
There’s also the Bose subwoofer enclosure on the rear deck, the amplifier is under the plastic cover in the luggage compartment. There isn’t a great deal of space so any replacement amplifier needs to be compact.
My choice for this Porsche was the fabulous Audison Prima 8.9Bit. This powerful, compact amplifier boasts plenty of output configurable across all 8 channels, along with a sophisticated digital signal processor. This processor allows me to carefully tune each speaker individually to create the perfect sound in any space.
Once a new amplifier plate has been constructed the Audison fits perfectly. Again everything is isolated against possible vibration with cloth tape and secured.
Now, to the speakers.
The first speaker to address is the tweeter on the dash. The location is fine, but the space available is very limited.
There arent many high-quality tweeters available to fit this space, but I chose the JL Audio C5 component system. This wonderful, German-built driver is just sublime: super smooth output and high power handling characteristics from a tiny form factor. I manufactured a custom cup that supports this tweeter in the dash whilst allowing for a slight tilt into the cabin. Once the grill is replaced the car looks completely stock.
To the doors!
As mentioned, each front door houses a 70mm mid and a larger woofer. The choice of which speaker set goes here will be determined by each customer’s personal musical preferences. Rather than forcing the performance through the amps DSP, it’s better to start with the appropriate speaker and gently tune.
For this installation, the owner wanted great clarity and detail with vocal performances in mind. Therefore, I chose to use a mix of Hertz Mille woofer and Mille Legend mid.
The Mille woofer is a fabulous low/mid driver that’s punchy and capable of great low-frequency extension. As the Porsche already had a subwoofer installed, I wouldn’t need a lot but knew that this affordable driver could deliver everything and more.
The Legend series is one of my favourites, and so the natural choice for vocal detail was their 70mm mid. It is definitely worth spending the extra here. Again for both speakers, I manufactured mounting collars to ensure a perfect fit and acoustic isolation.
I also added copious amounts of Dynamat sound deadening inside the Porsche doors to improve acoustic performance. (Bear in mind you can’t see it in these photos!)
Time to tune…
Once everything is installed and working perfectly it is time to address the tuning. This system is fully active, meaning that every speaker has a dedicated amplifier channel to power it. As there are no passive filters it’s essential that the amplifier only supplies the correct frequency range to each speaker. I know these frequencies pretty accurately, but always use a spectrum analyser to ensure there are no cancellations caused by the speaker locations. This is also an essential tool when blending the mid and woofer drivers to check for any crossover phase cancellation.
The next step is to analyse the output and correct for time alignment to make sure the stereo image is exactly where I want it. After this, I can check and correct the equalisation for spectrum anomalies caused by reflections and absorptions of the interior. This can be a long process but is essential to realise the full potential of the system. When it all comes together, the results are stunning.
What a difference!
After over 35 years I still get excited when a car sounds this good. Listening to a system like this is such an experience. You can’t help but tap your foot and sing along all in your own, leather-wrapped, high power space!
Every car and owner is different, which is why the tuning process is so important. To learn more about this Porsche 997’s system, or how we can improve your car audio, please call 01625 432707.
In these difficult times, we’re taking every precaution to keep everyone safe. Therefore we’re only opening the workshop by appointment, so it’s essential to call before travelling to see us. Alternatively, you can message me on our Facebook page or email email@example.com
Stay safe, Tim.