For many years consumers have taken on the challenging task of upgrading their factory amplifier as a weekend project. But six hours later, after many blown fuses and power wires running over the top of the fender, they haven't finished and have to take a taxi to work come Monday morning. We've all been there and have felt the frustration of defeat. Blaupunkt introduced its THA 475 PnP amp a while ago and it's now available for purchase. It's claimed to be a true plug-and-play product for the DIYer, but is it really that easy to install? Is it a true plug-and-play? We tested it out and checked its performance as well.
The Amp
Blaupunkt offers over 40 different car-specific harnesses to fit your vehicle, so I chose the correct fit for my '06 BMW X5. Note that the harness is sold separately. Included in the box is a 9-foot preassembled cable with plug fitted on both ends and spare plugs for different applications. The amp has a very simple rectangular look with no added clutter or heat sinks. The THA 475 PnP is fitted with crossovers, with highpass filters ranging from 10 to 250Hz and lowpass, 50 to 250Hz. Additionally, there are RCA inputs for front and rear channels with a line out and two mini plug aux inputs for other sources, such as portable devices, but they must be used with Blaupunkt's optional cable. This amp's performance is rated at 4 x 75 watts at 4 ohms, 4 x 85 watts at 2 ohms or 2 x 180 watts at 4 ohms bridged.
Installation
Since the amp measures only 1.6 inches in height, I installed it under the driver's side seat. Also, with only 9 to 10 feet of cable, I really didn't have many other options. The next step was removing the factory head unit, which only required a single #T10 Torx bit tool. After removing the radio I uninstalled the driver's side underdash and side molding, both of which were easy to remove. I then detached the factory harness from the head unit and replaced one end with Blaupunkt's direct fit plug and attached the factory harness to the other end.
Running the wire from the opening of the head unit space down the underdash and under the carpet of the driver's side seat was straightforward. Assembly of the amp wiring was also pretty simple since the wires plug directly into the amp without any tools. The plugs are labeled and fitted so there can be no mistakes. The entire process of the installation took only 30 minutes, including mounting two tabs to hold the amp. This was truly a plug-and-play product, but how would it sound?
Listening
When I started the car I didn't hear any engine noise or sound coming from the amp so I raised the volume and, voil, there was music. The amp worked and did a great job straightaway. Instantly, I heard a difference. The BMW X5 already has decent sound so I didn't think this little amp would make that much of an improvement.
The first thing I did was listen to the Eagles' "Hotel California" because on the OE system, this track can sound very harsh in the upper midrange with an over abundance of mid- and low-bass notes. After only a couple of minor adjustments to the highpass and the level adjustment, I was ready to take a listen. Don Henley's voice no longer sounded as piercing and the kick drum was tighter and didn't overextend the drivers, which made the test very enjoyable. I also needed to make sure the amp had volume, so I threw in Laurent Garnier and listened to it at a non-respectable neighborhood level. Before I knew it an hour had passed and my ears didn't feel fatigued.
Overall, the THA 475 PnP worked well to smooth any of the peaks that were exhibited from the factory amp and I felt the sound had more presence and depth. The attack in the midbass was dramatically improved and there was great tonal balance.