Replacement Superhub - move next to Tivo box?
We originally had our cable modem upstairs at the back of the house. We recently had Tivo installed downstairs and as part of that now have a new internal wall box fitted next to the TV.
We've just been sent a Superhub to resolve our low upstream speed with an old cable modem, and had hoped to move the modem downstairs. However, I've discovered that the wall box downstairs only has a single port on it.
I realise I need some sort of splitter, and looking around I can see basic splitters (which I'd connect to the isolator) and isolator splitters (which would replace the existing isolator).
The current single port isolator downstairs (TRIS-1002L) has 0.4dB loss (5-1000MHz). The upstairs isolator is a VQ601, which looking online seems to have 0.5dB insertion loss.
It seems that all splitters, whether basic, or combined splitter/isolator have greater losses, and therefore will affect the signal into the existing equipment - my previous modem reported:
Downstream Receive Power Level: 4.63 dBmv
Downstream SNR: 36.33 dB
Upstream Transmit Power Level: 38.00 dBmv
I don't offhand know what the Tivo reports (or whether it reports anything to the user).
Am I likely to get issues if I use any kind of splitter? Do people often to this without problem or do most people find they then have issues?
Finally, if I didn't change any cabling and just replaced the Superhub, is it likely/possible that the Superhub may have different signal requirements to the old modem, and therefore find that I need an engineer to come to adjust things? If an engineer did come with the intention of adjusting the signal levels, is there any chance he would agree to fit a splitter downstairs and adjust the levels for that?