Hello @Tim8805
The nominal Output Power (Downstream) of an 14 dB Amplifier is 82 dBµV @298 MHz and 84 dBµV @834 MHz (a positive slope to compensate the high attentuation of long cables)
A sixway Splitter has an decoupled (nominal) attentuation of 10 dB.
84 dBµV
- 10 dB (6-Splitter)
\= 74dBµV on the Port
This is, even you thought, to high power. The optimal level for the cable modem is between 58-66 dBµV.
An 11 dB Wall Outlet is perfect for star-topography.
74dBµV (Port)
- 11 dB (Outlet)
\= 63 dBµV @834 MHz (61 dBµV on the lower frequency 298 MHz)
Never forget the terminator on a Splitter/Througput Port (Outlet).
Your Modem compare to EuroDocsis 3.↉.1, this standard definate the power level for Downstream/Upstream.
Here is a Quick overview:
https://www.pickmymodem.com/signal-levels-docsis-3-03-1-cable-modem/
I hope, i has helped you (and all other customers in the cell)
Greetings
René