Any Fixes for Amplifi HD & Spectrum?


  • I am not a very technically savvy guy, but I know the basics. I am frustrated reading through these old threads going back to 2018 and seeing them end with no diagnosis or fix. So I am posting a tale as old as time... Amplifi speeds vs ISP speeds delivered to the Modem are abysmal and I would like a fix or direction.

    My set up

    • AmplifiHD running Firmware 3.3.0
    • Spectrum Ultra 400 Mbps - ethernet direct test at 425 mbps down ( sorry I don't remember up)
    • Amplifi app tests running 97.5 Mbps down - 138 Mbps 23 up
    • Wifi test from browser on Macbook Air - 26 mbps down 24 up speedtest.net
    • Network Type set to DHCP
    • Internet Settings - Hardware NAT is on and UPNP is on all other internet setting below UPNP is off.
    • Wireless Settings (I don't know what most of this means) - Security WPA2 PSK - Hidden SSSID off Router additional ssid both 5 & 2.4 off. Band Steering on - Router Steering off. Advanced - 2.4 GHZ automatic on bandwidth 20mhz / 5 GHZ automatic on - bandwidth 80 mhz

    Help please!


  • @Jack-Emery Do not rely on the Amplifi apps speed test, it is known to be bad. I have an HD, Spectrum Ultra and I am getting the expected speeds. I am really surprised about the speedtest.net numbers.

    My numbers are:
    Amplifi app - 157.5 Down, 20.6 Up
    iPhone Speedtest.net app - 323 Down, 20.7 Up
    Browser speedtest.net - 370.44 Down, 19.75 Up

    The settings I have that are different than yours are:
    UPNP - Off
    Additional SSID - Off
    Router Steering - On
    2.4ghz and 5ghz - Off

    Make those changes and see if there is an improvement.


  • @Jack-Emery Do you have a combo modem/router/WiFi from Spectrum or just a modem. I had them install just a modem in my home and I Get expected speeds. When my in-laws signed up we requested just the modem but they installed a combo device that was supposedly set to just work as a modem. The problem was that every few days, for some mysterious reason that Spectrum could never figure out, the combo device would switch back to router mode instead of bridge mode, which meant that there was a double NAT from the Spectrum router and the AmpliFi. I was calling every few days for them to reset their router to bridge mode. They finally came out and installed a simple modem and everything has been much better.


  • @James-Ford Thanks! Made the changes - We are seeing perfomance improvement on some devices not others... which is even stranger.


  • @Jack-Emery Good to hear. What devices are not seeing speed improvements? Are they WiFi-only devices? If WiFi are they connecting to a Mesh Point or the HD?


  • @James-Ford As an example - Yesterday - my partner and I sitting side by side - me on a 2018 Macbook Air (50Mbps) him on a 2019 MacBook Pro (360 Mbps). Of course today neither of us are clocking over 50 Mbps on any device - it seems to have slowed down. I am not sure how to tell if a device is hitting a meshpoint or the main router - I don't see in the device menu of the app where it tells you. Sorry I am not as tech savvy as most people on this community site, but I really appreciate the help. We don't have anything wired except for our security system and our Sonos main station.


  • @Daniel-Greenhalgh it is just a modem not a combo. Arris TM1602A MTA (its a motorola product). I am wondering if it is a conflict related to our ADP system and/or Sonos but that is pure speculation.


  • @Jack-Emery Unplug the mesh points and test against the HD. Then plug the mesh points in one at a time, and test before plugging the next on in.


  • @Jack-Emery We have a Sonos system as well but one of them is hardwired so they run their own SonosNet.
    I was experiencing slow downs at my in-laws’ (though not as bad) until I disabled the AmpliFi ad-blocker in the web UI.
    Have you tried giving some of the more important devices a different priority under the devices tab of the app? That made a difference for some of our devices.


  • @James-Earl-Ford Finally got around to doing this as well as changing my ethernet cord and getting an adaptor so I could do a wired test directly to the cable modem. I added the meshpoints one by one checking my speeds each time which held steady at that moment (see more below) ... here were my results-

    Wired to modem - Speedtest.net down - 476.97. Up 9.28 ping 31ms
    Fast.com. 480 mbps down - 19 up ping 42ms

    WiFi only hd no mesh points -
    Fast 470 down 25 Ping 50 me
    Speed test 474.71 down 23.41 up ping 31

    1 mesh point added -
    Speed test 336 down 23.52 up Ping 35
    Fast 470 down 24 up ping 73 loaded

    2nd mesh point
    Speedtest 417.57 down 23 up ping 35
    Fast 480 down 24 up Ping 47loaded

    3rd meshpoint
    Speedtest 478 down 23.5 up ping 33
    Fast 360 down 27 up. Ping 42 loaded

    That was great news! I thought we had solved whatever the issue was however, in less than 24 hours we were seeing speed fall off again - we can go from 300mbps down near the Amplifi HD and then fall to 25. The strangest phenomenon is that the up speed is staying pretty steady around 24 or so. When it drops low during a speed test I immediately connect to the modem and am still getting a consistent 400+.

    Any thoughts?


  • @Jack-Emery My up speed remains constant and I have heard that it does for other Spectrum users. The 2 things I can think of are (1) replace the modem, (2) get Spectrum out to check the wiring to and if there is any of theirs in your house. We use own a house and had a similar problem and after a lot of testing they finally came out thinking it was the modem but the problem persisted after changing the modem. Further testing and they found that it was a wiring problem where the internet entered the house.


  • @James-Earl-Ford Thanks for the insight - I think the modem is fine - it is hitting 400+Mbps on every direct wired test. I am just not sure the amplifi is working consistently for us. I have been having an ongoing back and forth with amplifi support and have made all of the changes or tested the changes they suggested but it isn't getting any better. After receiving my last set of support logs they asked me to send them the Mac address of the connected devices as well as additional set up information. I am going to get that together today, but I am about ready to give up and go buy the new google nest network. Our next door neighbor has it, has the same ISP service, and everything else. He is getting 400 all over his house which is very similar in build type to ours (100+ yo home with plaster walls etc...). I will keep everyone posted.


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