Hey,
Your logic isn’t very mathematically based! :)
Let’s start at the beginning. 89 dB means you get 89 dB with just 1 watt 1 meter away.
At 7 Watts your gain is about 8.4 dB, or about 97 dB at 1 watt 1 meter away. That’s quite noticeable output. :)
You can use this calculator: