Introduction
The goal was to replace the stock front speakers for improved sound quality. The factory, stock system is fairly decent, but the highs are harsh, and the bass boomy. While some advocate replacing the entire system, I wanted to save money and effort and try to make minimal changes and see if I could work within the given system.
The project car is a 2011 Volkswagen Golf TDI with the Premium 8 stereo. This is rumored to be a 4 channel system with 20 watts per channel. If intending to drive speakers from the factory amp, it would be wise to stick to speakers that are efficient. I looked for aftermarket speakers that had sensitivity ratings of 92db or greater.
Installation
(under construction)
Results
I analyzed the frequency response with a test CD and sound level meter. Note that frequencies over 10k are not reliable as the sound level meter will naturally roll off by then. Also, there is some error involved in the measurements, so I would not take it as too exacting. Some of the frequency response may be due to an EQ built into the stock head-unit; it may not be possible to get a flat response (or at least a smoother response) without replacing much of the system.
The stock tweeter had a very high peak. With the Polk crossover set to -3db, the Polk tweeters were better, but still peaked a bit. Bass in the new speakers was reduced, but mostly at the low end. Mid-bass is strong. This is good for rock music, but with some electronic or hip-hop/rap music, a sub may be required. The system can play fairly loud, and if the very low bass is not so important, this is a worthy upgrade.
