Improving Comcast modem signal

You don't have to rent xfinity's xFi Gateway modem, which appears to have its own internal PS.  You can buy your own and quit paying the monthly rental fee.

I use an ARRIS SURFboard modem (not the latest version) that has an external DC power supply, as do many other available modems made by folks like MOTOROLA and NETGEAR.  By purchasing your own modem, you could then use whatever LPS you want.

When looking at the newer modems, I noticed the ARRIS SURFboard SB8200, a  DOCSIS 3.1 Gigabit Cable Modem, also provides dual Gigabit Ethernet ports.  I will be curious to hear from people who know more than I do whether using the second Ethernet port to send a direct signal to my audio server, separate from the rest of my network, would further isolate the server from noise on the network or whether using an Ethernet cable out of my router to a switch offers the same level of isolation - i.e., is there any benefit to having/using a second Ethernet output from the modem?

The rentals equal out the cost of a new ARRIS SURFboard SB8200 in about 10 months.  After that, your modem costs are free. In 16 years, I have purchased 4 new modems (always for purposes of updating) and had zero issues.  Figure an average of a year of rental fees to pay off each of the four modems, and the result has been 10 years without the $14/mo fee, a savings of $1,680

People who live in areas that are susceptible to having problems can always add the additional service fee to pay less for visits.  One caveat is that your self-purchased modem needs to be on their current/approved list, i.e., it cannot be outdated.

@fuzztone - 

Shooting yourself is preferable to going to the "store" around here.

You sound a bit frustrated with the local service. I assume Comcast is no longer on your Christmas card list!