Instead of focusing on the number of bars or decibels, it's more important to consider the coverage area provided by a signal booster
Every signal booster is designed to increase the strength of the existing outside signal. The amount of decibels that the signal is increased by varies based on the initial strength of the existing outside signal, boosting power of the amplifier, and signal loss that's experienced from the cable and components while the signal is in transit. So while the amount of boosting is different for every situation, the amplifier is designed to provide as much boosting as possible, given the circumstances.
Coverage Area is More Important
Rather than evaluating a booster based on the amount of dB gain or bars that it's going to increase the signal on your phone by, it's usually better to think in terms of the size of the coverage area that the booster will be providing based on the outside signal strength. Within the coverage area, the signal should be strong enough so that you can maintain a quality phone call and have much faster data speeds.
Outside Signal Strength Matters
As a rule of thumb, the weaker the existing outside signal, the smaller the coverage area that the signal booster is going to be provide inside of the building or vehicle. If the outside signal gets stronger, the booster will be able to provide more coverage, until it gets to the point where the signal outside hits a maximum threshold and the coverage will be at its largest.
How Amplifier Strength Affects Coverage Area Size
While the previous example illustrates how the strength of the outside signal directly impacts the size of the coverage area, in most real world scenarios, the signal strength is mostly likely going to stay constant, unless you're in a vehicle and are moving between towers.
In this case, the way that you would grow or shrink the size of the inside coverage area is going to be by using a stronger or weaker signal amplifier. An entry level amplifier will provide you with the smallest coverage area, which may end up being just a few feet from the inside antenna, while the strongest available amplifier will provide you with the largest possible coverage area.
As long as you're able to make and receive calls, and have fast data speeds within the space that needs better signal, then the signal booster performance will be considered a success, irrespective of how many bars or decibels the signal has been improved by.
If you need assistance selecting the right signal booster for your situation, please do not hesitate to call 800-590-3564 or email sales@ubersignal.com and one of our signal experts will be happy to help you.