Several reviews of the Evo 3D have indicated that signal strength of the phone has been very poor. As far as I know, these determinations were made subjectively, and no review I read provided a quantitative analysis of signal strength. So here's a scientific approach to determining whether we have a problem or not with this phone's ability to pick up signals.
Test 1: side-by-side
Putting the phones next to each other, with about 2 inches distance between, I measured signal strength with the
OpenSignal app*. See picture:
Immediately, you should notice that the color reproduction on the Evo 3D is vastly superior to the Evo 4G. Note the purple tint on the Evo. The background of the app should be a neutral gray, which the Evo 3D accurately portrays. Ok, onto signal strength.
The info balloon shows that the two phones have picked up on the same tower. Note the latitude/longitude coordinates for the tower match exactly. In this picture, the Evo 3D is picking up a stronger signal than the Evo 4G: -81dBm vs. -89dBm. Over the course of 1 minute, the fluctuation range for both phones are:
Evo 3D: -81dBm to -85dBm
Evo 4G: -85dBm to -97dBm
Test 2: side-by-side + position swap
This test is the same as the first, but the positions of the phones are swapped to eliminate the RF interference bias. Evo 3D wins again in a one-minute test:
Evo 3D: -85dBm to -87dBm
Evo 4G: -91dBm to -101dBm
Test 3: phones 10 feet apart
Phones are now placed approximately 10 feet apart from each other in an open space (different room in the house from test 1&2), where obstruction from furniture is negligible or equally biased. Phones performed comparably within the minute of observation:
Evo 3D: -73dBm to -78dBm
Evo 4G: -73dBm to -73dBm
Test 4: phones 10 feet apart + position swap
This is the same test case as test 3 but phone positions are swapped to eliminate any positional advantage. Again, phones performed comparably:
Evo 3D: -73dBm to -73dBm
Evo 4G: -73dBm to -78dBm
These initial tests show that when both phones are locked onto the same tower and therefore are exposed to the same amount of radiation, there is little difference between the phones' ability to pick up a signal.
Wifi signal strength test
The app also measures wifi signal strength. When both phones are connected to my home wifi router, the Evo 3D consistently outperformed the Evo 4G. In a two-minute observation period with the phones next to each other, the following ranges of strength were observed:
Evo 3D: -57dBm to -60dBm
Evo 4G: -68dBm to -77dBm
Both phones were then made to load speakeasy.net's speed test. The following picture shows the benefit of the stronger signal on the Evo 3D (top):
The two numbers near the bottom of each screen correspond to the downstream and upstream speeds in Mbps:
Evo 3D: down: 20.03Mbps, up: 12.35Mbps
Evo 4G: down: 13.52Mbps, up: 10.90Mbps
I can only conclude from these tests that there is
no deficiency in the Evo 3D's ability to pick up a signal, either from a tower or a wifi hotspot, when compared to its older brother, the Evo 4G. I am open to questions and/or criticisms of my methodology.
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*Special thanks to EarlyMon for pointing me to the OpenSignal Map app used to measure signal strength of the phones in this test, and for suggesting that I perform the test to attempt to settle the signal strength debate over the Evo 3D.