T-Mobile Sonic 4G Mobile HotSpot Review

Laptop Mag Verdict

T-Mobile's Sonic 4G Mobile HotSpot is cheap and comes with affordable data plans, but inconsistent speeds make it a tough sell.


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    Pocket-friendly size

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    Available microSD card slot

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    Global connectivity


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    Inconsistent performance

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Running on T-Mobile's HSPA+42 network, the Sonic 4G Mobile Hotspot promises download speeds up 10 Mbps. Throw in USB tethering, global connectivity, an SD Card slot for sharing files among multiple gadgets and a helpful OLED screen, and the Sonic 4G Mobile HotSpot looks like a compelling device. But can it hang with the big boys from Verizon, AT&T and Sprint?

Editor's Note: We initially reviewed this hotspot on 11/9/2011, but have retested it more recently alongside competing devices from other networks. This review -- including its rating -- has been updated to reflect those changes.


Click to EnlargeMeasuring 4.0 x 2.2 x 0.6 inches and weighing 3.9 ounces, the oval-shaped Sonic 4G features a glossy gray paint job up top and black coating around its edges. In fact, the Sonic looks more like a smooth garden stone than a hotspot. The unit's black-and-white OLED display is the smallest among its competitors , but still managed to provide all of the pertinent information, including signal strength, battery life, the number of connected devices, network status and SMS messages.

On the Sonic's right side are its Power and WPS buttons. The left side features a single antenna port cover, while the bottom edge is home to the hotspot's microUSB port. The back panel has a soft-touch rubberized coating. Slide the panel off to reveal the Sonic 4G's 2200 mAh battery, SIM card and 32GB microSD Card slot.

4G Coverage

Unlike the other three big carriers, T-Mobile doesn't offer 4G LTE connectivity, instead choosing to rely on its HSPA+21 and HSPA+42 network to deliver high-speed data. The carrier says its 4G HSPA+21 network, which is capable of theoretical speeds of 14.4 Mbps, reaches 229 markets, while its HSPA+42 network, which can reach theoretical speeds of 42 Mbps, reaches 185 markets.

If you're heading abroad, you'll be happy to know that the device can be used internationally. Of course, as with the other hotspots in our roundup, international roaming rates will apply.


Like AT&T's Elevate 4G, the T-Mobile Sonic 4G Mobile HotSpot can provide 4G speeds to up to five Wi-Fi-enabled devices. Sprint's Sierra Wireless 4G LTE Tri-Fi Hotspot, however, can support up to eight devices, while Verizon's Jetpack 4G LTE Mobile Hotspot 890L can support as many as 10 devices. The Sonic 4G also offers users USB tethering, so you can use the hotspot when attached to your laptop (great for when you're running low on juice).


The T-Mobile Sonic 4G Mobile HotSpot was fairly inconsistent throughout our testing. Several times, our connection would drop despite the hotspot indicating that we had full service.

Using Speedtest.net, we measured the Sonic 4G's throughput at three locations in New York City: Madison Square Park, Bryant Park and Union Square. In every instance, throughput was at, or near, the bottom of the pack among hotspots we've tested. Its average download rate of 2.2 Mbps was well below the AT&T Elevate 4G (12.4 Mbps), the Sprint Tri-Fi (9.3 Mbps over WiMax), and even the Verizon Jetpack (7.3 Mbps). Upload throughput was even worse, at just 650 Kbps.

When we tested the Sonic under stress by streaming a 720p video to a notebook, speeds actually doubled, to 4.3 Mbps for downloads and 1.6 Mbps for uploads. Still, that's well below the leaders: The Sprint Tri-Fi averaged 8.2 Mbps down, and the AT&T Elevate averaged 9.7 Mbps up under the same conditions.

Large File Downloads

The Sonic's erratic speeds continued when downloading one large file. At Madison Square Park, it took the hotspot about 4 hours to download the 145MB OpenOffice install file. That same file took just 3 minutes and 8 seconds to download when we traveled to Union Square, faster than the AT&T Elevate 4G (4:22), and second only to the Sprint Tri-Fi (2:31). When we moved to Bryant Park, however, the file took 45 minutes to download. During testing near our New York office, the Verizon Jetpack 4G LTE Mobile Hotspot 890L downloaded the file in 2 minutes and 17 seconds.

Web Surfing

Surfing the Web with the Sonic 4G proved frustrating, to say the least. It took an average of 44.6 seconds to load CNN.com, 59.6 seconds to load NBCNews.com and 49.4 seconds to load Laptopmag.com. By comparison, the AT&T Elevate 4G took just 5 seconds for the first two sites, and 13 seconds for Laptopmag.com. Even the next slowest hotspot, the Verizon Jetpack, took just 17.9 seconds to load NBCnews.com and 12.3 seconds to load Laptopmag.com.

In Bryant Park, our connection speeds were so poor we couldn't even connect our laptop to the Internet despite the Sonic 4G showing full signal strength. Even after cycling the hotspot's power, moving to different locations around the park and trying to connect with two different smartphones and a laptop, we were still unable to get any kind of Web connection.

Battery Life

With its 2200 mAh lithium ion battery, the T-Mobile Sonic 4G lasted 4 hours and 55 minutes while running continuously over 4G. That's 10 minutes better than the AT&T Elevate 4G. The Verizon Jetpack 890L, meanwhile, lasted an impressive 6 hours and 10 minutes while connected to 4G LTE, while Sprint's Sierra Wireless 4G LTE Tri-Fi Hotspot and its massive 3600 mAh battery lasted 10 hours and 35 minutes.


T-Mobile sells the Sonic 4G Mobile HotSpot for $75 with a two-year data contract. At the time of this review, however, the carrier was offering the device for free. T-Mobile's least expensive data plan costs $39.99 per month for 2GB of data. The carrier also offers a 5GB plan for $49.99 per month and a 10GB plan for $79.99 per month. Go over that amount and T-Mobile will throttle your connection. If you pick up the Sonic 4G while it's on sale and choose the 2GB plan, you'll end up paying a total of $959 over the course of your two-year contract.


T-Mobile's Sonic 4G is one of the most budget-friendly hotspots around, but that can't make up for its serious flaws. With download and upload speeds that ricochet from one extreme to the other and website load times that go well past the one-minute mark in some cases, we suggest consumers opt for a more consistent mobile hotspot such as the AT&T Elevate 4G or the Verizon Wireless Jetpack MiFi 4620L.

T-Mobile Sonic 4G Mobile HotSpot Specs

Company Websitehttp://www.t-mobile.com
Data ConnectionEDGE, 4G, HSPA+, GSM/GPRS
Size4 x 2.2 x 0.6 inches
Supported Protocols802.11b/g/n, 4G, 3G
VPN SupportYes
Weight3.9 ounces
Senior Writer
A newspaper man at heart, Dan Howley wrote for Greater Media Newspapers before joining Laptopmag.com. He also served as a news editor with ALM Media's Law Technology News, and he holds a B.A. in English from The Richard Stockton College of New Jersey.