# Cable Modem Problem **URL:** \ **Category:** Factual Questions\ **Created:** [November 8, 2002, 3:08pm UTC](https://boards.straightdope.com/t/cable-modem-problem/135888 "2002-11-08T15:08:03Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![chickendoc](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@chickendoc](https://boards.straightdope.com/u/chickendoc)\ **Post date:** [November 8, 2002, 3:08pm UTC](https://boards.straightdope.com/t/cable-modem-problem/135888/1 "2002-11-08T15:08:03Z")
I’m having a problem with my cable modem. I believe that the problem occurs when I try to split the signal between my TV and cable modem. I’ve bought several top notch cable splitters but they either don’t work at all or slow the cable modem considerably when compared to a direct connect. Also, previous splitters have worked well and then slowed my modem down to a crawl after a month or two of use. Why is that? What am I doing wrong and what do I need to fix my problem? Thanks for your help. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [November 8, 2002, 5:52pm UTC](https://boards.straightdope.com/t/cable-modem-problem/135888/2 "2002-11-08T17:52:17Z")
You are doing something Very Wrong. Stop it and call the cable company. Cable modems/TV work quite differently from just CATV alone. They will put a quality splitter _and a special filter_ on the TV line. You don’t have the filter and are probably using an incorrect filter. Nowadays, with digital cable, etc., regular old do-it-yourself cabling is A Real Bad Idea. I have had regular Cable TV guys come out to my house, see that I have Cable modem, and call a _specialist_ in that is _certified_ to work on the line. You are not certified. You are not even Cable TV pro. In addition to you cable modem fouling up, you are also fouling up your neighbor’s connection as well. **This Is Not A Good Things.** ---
**Author:** ![Bongmaster](https://avatars.discourse-cdn.com/v4/letter/b/6a8cbe/32.png) [@Bongmaster](https://boards.straightdope.com/u/Bongmaster)\ **Post date:** [November 8, 2002, 8:28pm UTC](https://boards.straightdope.com/t/cable-modem-problem/135888/3 "2002-11-08T20:28:54Z")
I disagree with ftg here. Installing a cable modem in my area (Philadelphia PA) required no special “filter” or any other equipment other than a line splitter which you can get at any Radio Shack. I connect at an averge of 1.3mb a sec with no problems using either the splitter or directly connected. If you are experiencing intermittent slowness I would suggest it is a problem other than your splitter or lack of a filter. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [November 8, 2002, 11:44pm UTC](https://boards.straightdope.com/t/cable-modem-problem/135888/4 "2002-11-08T23:44:04Z")
Umm… ftg may have a point. Not all cable systems are the same and some breakouts may require more isolation than others. In any event, the problem may orginate a bit further upstream so calling the cable company is probably a good idea. [http://www.cable-modems.org/](http://www.cable-modems.org/) [http://www.cablemodemhelp.com/tvsplitter.htm](http://www.cablemodemhelp.com/tvsplitter.htm) [http://www.dslreports.com/faq/cabletech](http://www.dslreports.com/faq/cabletech) ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [November 8, 2002, 11:47pm UTC](https://boards.straightdope.com/t/cable-modem-problem/135888/5 "2002-11-08T23:47:30Z")
Umm… ftg may have a point. Not all cable systems are the same and some breakouts may require more isolation than others. In any event, the problem may orginate a bit further upstream so calling the cable company is probably a good idea. [http://www.cable-modems.org/](http://www.cable-modems.org/) [http://www.cablemodemhelp.com/tvsplitter.htm](http://www.cablemodemhelp.com/tvsplitter.htm) [http://www.dslreports.com/faq/cabletech](http://www.dslreports.com/faq/cabletech) > [@](#): > > Q: What kind of splitter do I want? (#3332) > > A: If you can flag down a cable guy and convince him to give you some free splitters, then good for you. If you can’t, then be prepared to spend some money. > > Those cheap looking splitters they sell at Radio Shack are NO GOOD. Do NOT use combiner/splitters. Combiners trash digital signal and make it almost impossible for cable modems and digital boxes to talk back to your provider. > > You want at least a 1GHz splitter. 900MHz usually work as well (unless your cable company actually goes above a gig, which I seriously doubt). > > The 1GHz means that the splitter is designed to pass signals all the way up to 1GHz. You may also have the option of buying power passing or not. You most likely do not need a power passing splitter. These are generally for special purpose applications (such as powering a signal amplifier that’s in your attic from the outlet in your bedroom without running a power cord to it). Also, do not get a bigger splitter than you NEED. The more ports a splitter has, the less signal it passes along to each port. Plus, they are more expensive. > > Splitters are NOT made to connect wires together. I’ve been to many houses where people used an old crappy splitter they had laying around to hook up 2 or more short wires to each other because they didn’t want to go out and buy a longer wire. SPLITTERS LOSE SIGNAL. Good brands that I personally have dealt with are Monster (expensive), Regal, and Cablevision. I’m not incredibly fond of Magnavox splitters (usually found at K-Mart).