The last two Bluetooth profiles, Advanced Audio Distribution Profile (A2DP) and Audio/Video Remote Control Profile (AVRCP), work together to give the KW-NT3HDT the capability to stream audio from a paired smartphone or Bluetooth audio adapter and control playback with basic play, pause, and skip controls.
In addition to Bluetooth audio streaming, another audio source is the aforementioned USB connection for iPod, iPhone, and mass storage device playback. Compatible digital formats include MP3 and WMA without DRM. The single-slot optical drive will read DVD video discs, retail audio CDs, and nearly any format of recordable CD that contains MP3 or WMA files.
Additionally, the KW-NT3HDT is satellite-radio-ready with a dedicated connection for adding one of JVC's XM or Sirius receivers.
The KW-NT3HDT uses a combination of an external GPS antenna, a vehicle speed pulse sensor, and an internal three-axis gyro sensor. The three systems complement one another to increase tracking accuracy. When GPS reception is weak, such as in urban canyons, the three-axis gyro can assist, notifying the unit when you make a turn to keep the vehicle on track. Another example is when the vehicle is traveling through a tunnel, the speed pulse sensor can help the KW-NT3HDT to effectively estimate progress until a satellite connection can be re-established. Additionally, the more you drive, the more the three-axis gyro calibrates, and--at least, theoretically--the accuracy of the unit will increase over time. We were still able to throw the system off with our test route through downtown San Francisco, but overall we found the accuracy of the KW-NT3HDT to be quite good.
The addition of HD Total Traffic to the navigation suite means that the KW is aware of conditions on the road around it. We spent some time hunting traffic jams reported by the service and found it to be reasonably accurate in its reporting. The system prompts you to recalculate when traffic appears on the chosen route, but it also has an option to automatically reroute without prompting.
If there is one weakness that we found with the KW-NT3HDT's navigation experience, it's the destination entry portion of trip planning. Address entry is fine, but in our experience the POI search system could use a bit more polish. Most heinously, our system refused to return search results for POIs near us; instead it kept attempting to direct us to drugstores and restaurants far outside a reasonable driving distance. For example, a search for "Walgreens" returned one result that was over 300 miles away, despite there being at least five locations within 10 to 20 miles. The KW continued to do this for the better part of a whole day for various searches, until a hard reset seemed to clear the issue and restore our local POIs. This may have just been an isolated glitch, but even when it works properly, the POI search function can be slow and a bit unintuitive, particularly when looking for a particular location of a large franchise chain. On the other hand, we had little difficulty searching for locations by proximity, for example finding the nearest gas station, or heading to known addresses.
Turn-by-turn directions are given with text-to-speech spoken street names, which we find very useful for keeping the driver's eyes on the road. The system does have a bad habit of expanding abbreviations unnaturally, for example stating "United States 101 South" instead of the more common and brief "U.S. 101 South." We can see some users becoming annoyed by the unnecessary verbosity, but we were mostly unbothered. There's also graphic lane guidance and a detailed intersection view for those times where you need a little visual confirmation.
Another neat feature is the speed limit notification that verbally warns you when you exceed the posted speed limit for the road on which you're traveling by a customizable amount. We found it to be quite useful for keeping our speed in check, but ultimately decided to disable the feature after receiving almost constant reminders that we were driving irresponsibly.
When we look at the bullet points and compare the day-to-day functionality, JVC KW-NT3HDT is on par with the double-DIN all-in-one units in its price range in all areas but one. It has the distinct double advantage provided by its built-in HD Radio receiver allowing it to tune in to HD Radio stations and receive HD Total Traffic data for traffic, news, and weather, features that could cost more than $500 extra to add to a competing model. Factor in the lifetime subscription to the Total Traffic service and the KW-NT3HDT starts to look like a downright steal.
Of course, as we mentioned earlier, the hardware isn't without its quirks, particularly the "Will it break this time?" USB cover and the huge detachable faceplate with its secret SD card slot. And while our POI search problem may have been an isolated incident, we feel it still bears mentioning. Even in that light, the KW-NT3HDT deserves a spot among our favorite in-dash navigation units. It's a very flexible system that offers a good many customization and audio input options, and earns our recommendation for users who are more concerned about getting around in traffic than a glossy, slick interface.