QuestionI just purchased a 2000 Mazda Miata with a very subpar factory stereo. Even with my hard top on the sound is not decent. When the top is down I can rear music if the volume is almost to full power, but on the freeway I can't hear any music at all. The speakers are installed in the bottom front of the doors with tweeters just below the windows also at the front of the doors. I would like to get a new system with good sound that I can hear with the top down on the freeway, but I don't want to spend more then $500. I don't expect audiophile sound in a convertible, but at least want to hear music. What do suggest for my situation? Do I need an amplifier? Can I put a 2nd pair of speakers closer to my ears somehow? What specs should I look for? Etc.
Thanks for the help,
Ken
AnswerHi Ken,
It's often a challenge to get good sound in a convertible. In fully enclosed vehicles, we can often get away with the relatively low power of a head unit amplifier, because the sound just has to fill a small space. However, once you open things up a bit, the limitations of a 10-15 watt/channel amplifier become more apparent.
I think your best option is to replace your front speakers with after-market upgrades, and install a 2-channel amplifier to drive them. You can do this without replacing the factory head unit if you wish, but you'll need a device called a line-output converter to make the new amplifier work with the factory radio outputs.
If you have the standard Miata audio system, your factory speaker is a 6x8". However, the opening in the door metal is 8" round, and the 6x8" speaker is just mounted in an adapter bracket. You have quite a few options for 6x8" drop-in replacements, and that would certainly be the least expensive option. On the other hand, the design of your door gives you the opportunity to install an 8" speaker--in fact, the factory Bose system uses an 8" speaker in this location. It wouldn't be practical to upgrade to a Bose package (they're only available as OEM equipment, not after-market) but there are a few 8" speakers available for car audio use. One set that you might want to look at is Focal's 210CA1 speaker. Focal is considered a fairly high-end brand, so these speakers are expensive; but they have the advantage of a relatively high sensitivity rating. This means they can play louder with a given amount of power compared to some other speakers. 8" car audio speakers are uncommon (unless you count subwoofers) but using this speaker size allows you to make full use of the space you have available. The Focal 210CA1 is available for about $250/pair from Crutchfield.com, but you might find it at a lower price from other retailers.
I'd also consider applying a damping material like Dynamat to your doors. This can improve your speakers' output by limiting the vibration of the mounting surface. As a speaker cone travels back and forth, it can induce a resonance in the door metal; and the energy used in making the mounting surface vibrate isn't being used to produce sound. Another advantage to the damping material is that it can be used to seal up the openings in the door skin. Speakers perform best if the rear of the speaker is completely isolated from the front, so it's helpful to seal off any gaps in the metal door skin.
I don't think there's any practical way to install new speakers in a location that's closer to you--it would certainly require some custom work, which would quickly take you past your $500 budget. You should be able to get adequate sound from the stock speaker locations, however, given sufficient power.
There are a number of 2-channel amplifiers that would work very well for you. You might want to look at Rockford Fosgate's P200-2 amplifier. The nice thing about this amp is its' relatively small size, which makes it easier to find a good mounting location in a small car like yours. However, you should get good results with just about any 2-channel amp rated for 50-100 watts RMS per channel.
In addition to the line-output converter, you'll need an amplifier wiring kit--a 10-gauge kit should be fine for an amplifier like this.
Hope this helps!
Brian
