Love local radio? Then it's time to check out the crystal-clear reception and high-quality sound that HD Radio technology brings to AM and FM broadcasts. Just connect this THD400 tuner to your Clarion receiver, and start enjoying what HD Radio has to offer. On participating stations, you'll hear AM that's as clear as FM, along with FM that's almost CD quality.

This tuner is compatible with select Clarion NX, NZ, VX, and VZ multimedia receivers. With your iPod® connected, you'll be able to "tag" tunes that catch your ear on HD Radio so you can buy them later at the iTunes store. Many HD Radio stations also broadcast more than one channel on the same frequency. The THD400 tuner allows you to select these additional channels, giving you even more listening choices. Dimensions: 3-13/16"W x 7/8"H x 3-1/4"D. Warranty: 1 year.

Hands-on research

What's in the box?

  • HD Radio module with attached 8" cable (terminated by a proprietary 8-pin connector)
  • 64" DIN-cable (with a proprietary 8-pin connector on each end)
  • 2 Metal mounting brackets
  • 4 Large machine screws
  • 4 Small machine screws

Product Research



HD Radio: HD Radio technology, where available, offers higher quality sound than conventional analog broadcasts and receives text data. HD Radio provides FM broadcasts that are equal to CD sound quality and AM broadcasts that are as good as analog FM stereo broadcasts. HD Radio also provides a variety of data, including station name, song title, artist name, album name, etc. No subscription fees required.

Note: Right now there are about 2,000 radio stations broadcasting using digital HD Radio technology in the U.S. To find HD Radio stations in your area, visit the HD Radio website (

Compatibility: The Clarion THD400 HD Radio Tuner connects to your Clarion HD Radio-ready headunit's HD Radio port. Currently the THD400 is compatible with following Clarion multimedia headunits (as of January 2010).

  • NX500
  • NZ500
  • NZ503
  • VX400
  • VZ400

Multicasting: In addition to conventional broadcasts, with HD Radio broadcasting it is possible to choose from up to 8 multicast programs (HD1 to HD8 and analog). There are also data programs for each program.

Display Information: The THD400 HD Ratio Tuner displays song title, artist and station information on the display of your compatible Clarion HD Radio ready headunit.

Analog Broadcasts: In addition to HD AM/FM stations, the THD400 can also receive conventional analog AM/FM broadcasts.

Presets: The Clarion HD Radio Tuner features 3 FM bands and 1 AM band where you can store your HD and analog AM/FM station presets. You can store 15 stations in each band, giving you a total of 60 HD/analog station presets.

iTunes Tagging: iTunes Tagging allows you to "tag" songs heard on the HD Radio Receiver. Tagging saves the song's title and metadata to a connected iPod (you may store up to 64 tags in the memory). When the iPod is synced to iTunes, a playlist is generated with links to the iTunes Store where the song can be purchased and downloaded.

Note: This function can be operated with the following iPod/iPhone models - iPod nano (3rd/4th/5th/6th gen), iPod classic (80/120/160GB), iPod touch (1st/2nd/3rd/4th gen), and iPhone (2G/3G/3GS/4).

Installation: The THD400 plugs into the HD Radio port on the back of your compatible Clarion HD Radio-ready headunit. The antenna cable from the Clarion headunit is disconnected and plugs into the antenna port on the HD Radio tuner.

Mounting: The Clarion THD400 comes supplied with two metal mounting brackets and mounting hardware to secure the HD Radio tuner in your vehicle.


Receiver Output: Proprietary 8-pin connector with 64" extension DIN-cable which plugs into the HD Radio input of your compatible Clarion headunit.

Antenna: Female motorola antenna port for connecting your vehicle's antenna cord. Unplug the antenna from your Clarion headunit and connect it to the antenna connection of the HD Radio tuner.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Clarion THD400 Reviews

Average Customer Review:

4 reviews
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Good sound, but integration issues

Written By RalphD, Pikesville, MD on Saturday, June 18, 2011

Crutchfield Customer Review (What's this?)

It is very easy to install and there is a noticeable difference in sound quality. BUT, when paired with my Clarion NZ500, it would not hold the presets between vehicle starts. I tried two units and the same problem occurred. Without the unit installed, the radio presets work perfectly.

If it works with your particular head unit without issue, then adding this product on is fine.

Clarion THD400

Written By Mack, New Orleans on Wednesday, June 01, 2011

Crutchfield Customer Review (What's this?)

This product is very good, I like the sound clarity, info display, extra stations and Itunes tagging. Its is very easy to install. Plug and play.

The only bad thing which depends on where you live the HD goes in/out sometimes, again thats base on your location. This is not the product issue its your local station signal strenght.

Not bad I think...

Written By Wayne B, Lexington, SC on Friday, December 03, 2010

Crutchfield Customer Review (What's this?)

This product was somewhat like the emperor's new clothes, It help bring out more clarity, rich
tones, etc. I THINK! I know that it is working but I'm just not sure what the difference is. I don't
think I would pay full price (and I didn't). I'm glad I've got it but I'm just not sure why. And of
course the emperor does look great (if you say so). I've said all this to say, I really don't want
to be without it. I just hope you enjoy yours as much as I do mine.

A Big difference for a little $

Written By KMO, Ft. Lauderdale, FL on Thursday, November 11, 2010

Crutchfield Customer Review (What's this?)

Simple to install and brings your tuner to life. The difference in sound quality is
noticeable and the extra stations only make it that much more enjoyable. A big
difference for a little $, which allows you to get the most out of your system.