Car stereo 2: Daihatsu Sirion2
In February, 2007, I bought a brand new Daihatsu Sirion2 1.0 premium. It's a roomy compact car with a 3 cylinder, 1.0 liter, 12 valve, VVT-i engine delivering 69 hp. The same engine Toyota uses in some Yaris and all Aygo models (my girlfriend drives an Aygo). For today's measures it doesn't seem like a lot of power, but I do get across the Alps swiftly with it. The Benzes and Beemers will just have to be a bit patient, that's all. Why did I pick such a small engine?
- The car averages 42 miles to the gallon (5.5 liters per 100 km) and 47 mpg (5 liters per 100 km) long-distance. Petrol is nearly as expensive as liquor in the Netherlands. The Dutch government imposes around 140% tax on gasoline.
- My country is flat, full of cars, and you can't go faster than 120 km/h even if you wanted to.
- In my county one has to pay ludicrous amounts of BPM tax and VAT tax on a new car, and this one had a substantial premium for being so environmentally friendly. Until 2012, the Dutch government imposed up to 66% tax on luxury cars.
- The small cylinder block heats up in about 1-2 minutes so the heating system and defrosting kick in pretty quickly.
- The engine utilizes a timing chain instead of a belt. A chain lasts much longer and is less prone to breakage. My previous car had to be scrapped due to a broken timing belt.
Furthermore, the Sirion2 is a pretty complete car, with its electrical power steering, anti-lock brakes, 4 power windows, electrical mirrors, 4 airbags, rear axle stabilizer, height adjustable driver's seat, and remote central locking. We did not get the optional air conditioning. Around here, we get heat a few weeks a year, tops. As for the car's looks... no, it's not the coolest fastest looking ride, but it is very good at doing what cars are supposed to do: getting you from A to B. And this car does it cheaply as well. The interior is very basic and plastic and an RPM counter is not provided for. I added a Scangauge car computer to make up for the lack of standard gauges, and I might upgrade the interior with a nicer looking material.
The Daihatsu has replaced the Fiat Marea Weekend I had been driving for 4 years. The Fiat was a pretty large station wagon (4.49 m) with room to spare. The amplifier, a Sony XM-604EQX, was installed invisibly under the back seat. The subwoofer was specially built to fit in the trunk against the LPG tank. Luckily, the cabinet fits very nicely into the trunk of the new car and the amplifier fits perfectly under the front seat.
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1. The sub is a 12" Monacor SPH-300TC with its 2 coils paralleled to give a 4 Ω total impedance. The driver is recessed into the heavily grilled front of a closed 25 liter reinforced plywood enclosure, finished with black carpet and black metal corners.
There's a lot more to the Sony than just the amplifier. Features:
- 4 channels of 60W continuous, 2 by 2 bridgeable into 150 W
- regulated power supply, so no need for a capacitor
- built-in variable crossovers
- a 5-band equalizer with bypass per channel pair
- a power meter per side
We ordered the Daihatsu without the integrated sound system. I felt the price was way too high for what you'd get: a radio/CD player and that's it. For the money I got myself a Tomtom ONE portable navigation device instead. As an audio source, I will be using a normal portable MP3 player (a Trekstor Vibez 12GB). This setup of MP3 player and amplifier has worked fine for years. I don't care about radio, and CDs in a car are too much of a pain. Then again, I might put a portable CD player in the glove box to be able to play CDs when I just bought some new stuff. I don't ever buy music online. I buy CDs.
The most risky job was removing the factory installed radio cover, which turned out to be a wrecking job really. To properly remove it you need to actually remove the whole heater console, because the radio cover is screwed on from behind. I thought it was just stuck and lost my temper: I struck a hole in it with a screwdriver and just pulled it out. Luckily only the cover itself was damaged. What were they thinking anyway?
2. For the required safety, I put a 30 Amp fuse as close to the battery as possible. For this I used a small 4-way fusebox bolted to an unused lug. The 3 spare fuse positions might come in handy for future stuff, or at the very least there's room for spare fuses.
Next was laying a single supply wire directly from the battery to the driver's seat. There's a rubber feed-thru right next to the brake cylinder. To reach it properly from the engine compartment you need to disconnect both battery clamps and move away the fuse box as far as it'll go. The fuse box is secured by a single nut on the left and a plastic clip retainer on the right. On the rubber feed-thru there's some sort of button that you need to poke a hole in and then feed the supply wire through. It might help to put vaseline on the wire. Once it's through, it's easy enough to put it under the interior lining, unless you're working with cable the size of starter leads.
I looked for a suitable place to connect the amplifier ground to the car chassis. There are a lot of places where ground wires merge, but none close to the driver's seat. So I lugged the ground wire to the seat mounting frame, which bolts directly onto the car frame. I was able to keep the wire very short because of this.
4. This is what it looks like under normal circumstances. When I'm expecting passengers in the back seat, I put down a piece of carpet so the amp won't get scratched.
The amp is set up for front left and right, and the 2 back channels are bridged into a single 150W channel, driving the subwoofer. Its remote power is diode-ANDed to the ignition and the parking lights. This way it's possible to listen to music while the engine isn't running by leaving the parking lights on. At the same time it's almost impossible to forget to turn off the audio system. The Sirion2 has a pretty small battery, and I don't want to run the risk of draining it while away.
The cable for the subwoofer was a bit less of a hassle. I just tucked it under the side lining and once I got to the back seat hinge I just pulled out the hinge cap and put the cable underneith it. The wires to the front speakers, remote wire and signal wire were also very easy to run underneith the middle console. There's a small unexposed area where the cables run through a black piece of plastic tubing.
At this point I decided to take a peak under the front speaker covers, and concluded what I already suspected: damn cheap stuff. You really have to not give a damn about sound quality if you're willing to listen to that. So those had to be replaced no matter what. Unfortunately there's only room for 4" units, ruling out the excellent 5" set I had lying around. Also in the junk box was a set of OK sounding 4" midbass drivers, but they were at least 15 years old and had to be complemented by separate tweeters, so maybe that wasn't such a good idea... Anyway, these look very good to me:
The real catch about these speakers is the fact that the tweeter is wired through the center with its own wiring, allowing me to retrofit the crossover. But, after a little thinking, I decided that proper Linkwitz-Riley filters with Zobel corrections would probably not be worth the trouble for a minor improvement in sound quality. Instead I just replaced the standard tweeter capacitor by an MK-type layered cap. They sound a little better, last longer and are more tolerant of temperature changes.
7. The Vibez MP3 player dock is mounted close to the ignition key, and is visible to the driver through the steering wheel. Unfortunately, passengers can't see the display very well, but they can at least control the player with the remote.
The radio slot used to be covered by a translucent red acrylic panel with a Scangauge 2 computer behind it. However, the Scangauge screen was illegible in daylight, and the acrylic attracted a lot of dust, so I redid it with a black panel, and moved the Scangauge to the storage compartment below the heater console. The Tomtom satnav is docked in front of the radio slot panel in a removable dock, made from a standard windshield holder. 5 Volts power to all gadgets is delivered by a Power-one 20IMX15-05-05-9 DC-DC converter behind the dash. This (quite expensive) converter has 2 isolated outputs, which will eliminate ground loops that might occur with the MP3 player. The same converter also powers the Tomtom satnav as its battery life is only a few hours.
10. I fitted a Scanguage II car computer in the storage compartment below the heater controls. As you can see, the Scangauge's backlight color perfectly matches the car's.