will a spliter work

[banker]

i'm thinking about getting Mediacom wifi but all my tv wires are in use, will a splitter slow down speeds?

 

[MrNiemo]

I assume you're talking about a cable modem.

The splitter should work fine, and it won't affect the connection speed.

 

[Karadjgne]

Depends on the splitter and exactly which connection is used. Don't go with an el-cheapo splitter, many have 7-15db drops and aren't shielded internally, which can easily corrupt data. Some splitters have a 3db and 2-3x 7db drops, you'll want the modem on the 3 as its the least invasive. Just don't use an amplified splitter, the interference will drive your modem nuts. Stick with a plain Jane passive.
Also, make sure any and all cables are decent quality, nothing will drop connection speeds faster than crappy cables with bad terminations. If at all possible, at the main junction box, separate the line you want to use on a single split so the modem is on the line with no other splits before that first. So if the cable input is tied to an 8 way splitter, change it to a 2way first, with that line dedicated on 1 and all others still connected through the 8way on the other. The fewer connections as possible, the better your data speeds will be.

 

[banker]

I mean like this https://www.amazon.com/RCA-DH24SPF-Two-Bi-Di-Splitter/dp/B0018BQR84/ref=sr_1_3?ie=UTF8&qid=1478557923&sr=8-3&keywords=tv+splitter+2+way

 

[MrNiemo]

Yes. Should be fine.