4-channel amplifiers ?
John P's 2011 Subaru Impreza
After a little over a year of driving my 2011 Subaru Impreza, I knew it was time to change out the system from factory-equipped to an aftermarket setup. It also made sense to upgrade since I write all things speaker- and subwoofer-related for Crutchfield, and I get to hear amazing car stereo equipment on a regular basis thanks to our labs. The final product sounds amazing, and helps me enjoy riding around town even more.
- Pioneer AVH-8400BH DVD receiver
- Helix Competition C62C component speakers
- Helix Precision P12W 12" subwoofer
- Helix Competition A4 4-channel amplifier
- Helix P-DSP 8-channel digital signal processor
- StreetWires ZeroNoise 3 amp wiring kit
- StreetWires ZeroNoise 7 4-channel patch cable
- (2) StreetWires ZeroNoise 7 2-channel patch cables
- StreetWires 14-gauge Super Cable speaker wire
- StreetWires 12-gauge Ultra Cable speaker wire
- Axxess ASWC steering wheel control interface
When I approached this project, I knew I wanted the system to sound like a nice home stereo setup while being as hidden as possible. I also wanted to be able to turn it up loud when I wanted to because I listen to a good bit of Electronic music (Drum and Bass, Dubstep), Alternative, and Rock.
Why did you decide to upgrade your A/V system?
I'll be honest, I don't have the longest commute. But after being surrounded by some high-end gear all day, it's kind of a letdown to hop in my car and strain to hear details. And there was practically no bass! That's no good if you enjoy electronic bass lines. So I finally decided to take the plunge and do it right.
|The Pioneer AVH-P8400BH controls the system.|
What's the first thing you show people about your installation?
The first thing I generally do is make someone sit in the driver's seat and crank it up. Since there isn’t any stereo equipment visible except for the tweeters and the Pioneer receiver, people generally have no idea what to expect. I have them sit in the driver's seat because the system is optimized for that location and you get the best imaging there. It's funny watching their jaw drop when I crank it up.
After that, I show off the clean installation in the back and the hidden DSP under the spare tire cover. I also inform the listener that there aren’t any rear speakers (just the set in the front), and that's generally pretty shocking for people because there is so much sound coming from so few speakers.
|The sub and amp are hidden under the cargo cover (click to enlarge).|
Why did you choose these products?
|The Helix P-DSP fit under the spare tire cover in the trunk with a little modification.|
We started carrying Helix equipment recently, and the first time I listened to their gear in the labs I was blown away by the level of detail they produced. After that, I knew that they were the brand I wanted to go with. I decided on a pair of component speakers in the front, with only a 12" subwoofer in the back to get the best imaging possible, because rear speakers can muddy the soundstage if you're not careful. And the Impreza is such a small car, I don't really need them. I went with a 4-channel amplifier, and each woofer and tweeter set receive one channel of power through their corresponding crossover. The remaining two channels are bridged together to power the subwoofer.
The DSP was a no-brainer because a system that doesn’t account for the acoustics of the vehicle doesn’t perform as well as it should. And I found that to be totally true after I connected everything without programming the DSP and gave it a listen. It really sounded kind of sterile after a rough tune, and nothing was blended well. After tuning the DSP it was another story altogether!
What was the most difficult part of the installation?
For me, one of the toughest parts was using a hole saw to modify the factory sail panels. The Helix tweeters are huge, so the opening had to be pretty large and there wasn’t much room for error. I took my time, and actually went through the back of the sail panel to center it. I'm pretty stoked with the results. The tweeters look pretty symmetrical and they're mounted in there really well.
|The tweeter mounted in the factory sail panel.|
Other than that, programming the DSP was the most challenging non-installation related portion, but it made the biggest difference in how the system sounded by far. To do this, we put the microphone of an RTA (real time analyzer) in the driver's listening position, and ran pink noise through the system at high volumes. The RTA showed us different frequency levels in real time, so we could make adjustments on the laptop that was connected to the DSP. All-in-all it took about three and a half hours to get right, but man, it sounds phenomenal!
What plans, if any, do you have for future upgrades?
Dynamat! I'm getting some rattling now that I have a full system in place, so I intend to add Dynamat to the doors and rear hatch to help squash some vibration-related noise. Once it's installed, I should be able to hear a lot more and keep the volume down lower to still get the same SPL (sound pressure level). All that's left after that is to enjoy the system.
|The Helix A4 amp mounted to the rear seat so the seat can still fold down (click to enlarge).|
Vehicles in the Custom Car Showroom are submitted by customers, fans, and as in this case, employees. You can find more of these articles on the Showroom main page.