22. Text-to-Speech Voice Quality

Speech quality on the nuvi 660 is identical to that of the StreetPilot c550. In my testing, the nuvi did a decent job pronouncing street names and I didn't find the voice abrasive or irritating.

The nuvi will also perform text-to-speech on saved addresses in your address book. So if you save an address as "Work", when arriving at the saved location, the nuvi will announce "arriving at work".

23. Real-Time Traffic Data

The nuvi 660 shares the same 12/24-Volt adapter with integrated traffic receiver as the StreetPilot c550. Both units ship with Garmin's GTM 20 (integrated receiver, antenna and cigarette lighter adapter).

Figure 76: GTM 20 integrated receiver, antenna and 12/24v adapter

The nuvi 660 is one of the few GPS units I've tested that actually comes with everything you need to receive real-time traffic updates. Most other units require that you buy additional hardware, and in some cases (TomTom) that hardware isn't even available yet.

Using the included integrated traffic receiver / 12v adapter, the nuvi 660 is able to receive traffic information broadcast over the RDS system (FM Radio Data System -- this is the same system that displays the song you're listening to on some FM radio stations). When a traffic message is received, the nuvi 660 displays the incident on the map and can change your route to avoid the accident/traffic.

Figure 77: Garmin Traffic Icons

If there is a traffic event received that impacts your current route, the nuvi displays the appropriate icon (from the table above in figure 64) in the lower-right hand corner of the map display. Touch the icon, and you can view the details of the traffic issue, or tap "Avoid" and get routed around the problem. Even if you don't manually view the traffic event, if the nuvi detects a traffic event and can find a better alternate route, it will prompt you saying a better route is available, and would you like it to automatically re-route you.

Garmin has implemented the traffic feature in a very intuitive way, and you don't need to read the instructions to use it. Be aware that currently traffic data is only available in larger, city areas. For a list of supported cities, visit Garmin's website.

The 660 comes with a complimentary 3-month traffic subscription. After that, It'll cost you $60/year (for service in the United States).

24. Using the FM Transmitter

The integrated FM transmitter is one of the best things about the nuvi 660. I was really surprised at how much it added to the user experience. It does add a (small) layer of complexity, but it's hard to deny the benefit of having the navigation system, hands-free speakerphone, and music playback all integrated into your car's stereo system.

Figure 78: Audio Output Selection

Switching from the internal speaker to the FM transmitter is accessed by touching the speaker icon on the Main Menu page, then tapping Audio Output.

Note: A quicker shortcut for switching between the internal nuvi speaker and the FM transmitter is quickly pressing the power button twice.

Figure 79: FM Transmitter Frequency Selection

The first time you set the nuvi to use the FM transmitter, you are prompted to set the frequency it should broadcast on.

Figure 80: Setting the FM Frequency for the Transmitter

Although you can manually set the FM frequency, the nuvi has a handy Auto Tune feature that will automatically scan the FM dial and find an unused frequency to use. Once the nuvi finds a suitable FM frequency to use, simply set your car's FM stereo to the same frequency and you'll hear the nuvi's output.

My only complaint about the FM transmitter was the weakness of the signal. In my car the antenna is located at the rear of the car, so it's a good 5 feet or so from the windshield, and I noticed some crackling and interference. Garmin's documentation says the unit is designed to be placed near the FM radio, and that vehicles that have the antenna far away from the radio may experience less than optimal quality. That was definitely the case for me, but it was not so poor that it was unusable; music still sounded good and the static was only barely noticeable at high volume.