The first time we saw what looked like an extra HDMI port on a TV that was was labeled "MHL," we said, "Awesome!" Then we wondered, what the heck is MHL? Think of it as a technology that turns a common MicroUSB cable into an HDMI cable, but with a few special features.
MHL stands for Mobile High-definition Link, and it's the brainchild of a group of companies—including Nokia, Samsung, Silicon Image, Sony and Toshiba—that wanted a specification that could be used to connect smart phones, tablets, and other devices to an HDTV. As you'd expect, MHL supports 1080p video as well as 7.1-channel digital multi-channel audio, so it's an easy way to send high-def videos from your portable device to your big-screen TV. Great, you might say, but can't we already do that wirelessly?
Yes, but MHL adds a few cool new tricks. One is that it sends control data through the same cable, so you can control the portable device using your TV's remote. The other is that the cable provides power, so you won't drain your portable device's battery while the media is playing.
If you have a smart phone that supports MHL (and many newer phones, such as the HTC EVO 4G LTE and Samsung Galaxy S III do) and an MHL-supported TV, then the quickest route to trying this new technology is to get an MHL adapter cable, which has a MicroUSB connector on one side and an HMDI slot on the other. Just connect the MicroUSB connector to your phone, then run an HDMI cable from your TV's input to the HDMI slot on the adapter. No additional gear is needed.
But even if you don't have an MHL-enabled TV, you can still watch content from your phone. Many MHL adapters have an additional port where you can plug in your portable device's MicroUSB charger so it won't power down. (Some may use a separate charging dongle attached to the adapter.) But you likely won't get the remote-control functionality.
Fortunately, enjoying MHL doesn't cost that much. You can expect to pay anywhere from about $12 to $20 for an MHL adapter, although there are more expensive ones. (Note that Samsung Galaxy S III phones, which use an 11-pin MicroUSB port instead of the standard 5-pin connector, require either a special MHL adapter or an 11- to 5-pin converter for use with standard adapters.)
In addition to MHL-enabled smart phones, we're starting to see a growing number of other types of MHL-enabled devices, including TVs from Insignia (Best Buy), LG, Samsung, Sharp and Toshiba. And we also just tested the first MHL-enabled Blu-ray players we've seen, from Sharp.
MHL technology's profile may get a boost this fall when Roku starts selling its diminutive Roku Streaming Stick, a set-top-box-on-a-thumb-drive media streamer that plugs directly into a TV's MHL-enabled HDMI port. Several TV brands, including Apex, Element, Haier, Insigina, Mitsubishi, Onkyo, and Oppo, have announced "Roku-ready" gear that can use the Streaming Stick, and some will be bundling the Streaming Stick with the item.
Have you been using MHL to get content from your phone or tablet onto your TV? If so, let us know how it's working, and whether or not your TV is also WHL-enabled. I just ordered the MHL adapter for my HTC EVO 4G LTE phone, so I'll add a comment once it arrives and I get it working. If you want to check out a list of MHL-compatible devices, see the
MHL Consortium's MHL-Enabled Product List.
—James K. Willcox