Normally you can not have too much signal comming from the main cable. You
can not get a splitter with out any loss. Think of the signal as money in
the bank. YOu only have so much to start with. It is up to you to decide
on what to do with it. If you spend a lot on food, it leaves less for say
playing golf. You decide if you want stake or hambuger and a good set of
clubs or a less expensive set. You can get a booster or amplifier for the
signals to the TV sets if they are not clear.
All you have to do is unscrew the cables, and interchange them.
Sorry, couldn't resist.
I can't really answer your question I think, except to say that those
numbers do not represent output levels. For one thing, since no one
knows what the input level will be. And splitters are passive, so
output depends on input. So 7db is not more than 3.5.
Rather, when not referring to sound itself, I think decibels are a
ratio, and 3.5 decibels represents how much signal loss there is going
through this splitter. So 7db would be more loss than 3.5, not more
I don't have cable internet, but I had cable tv and still have lots of
tv's running off the output of my vcrs. For every three splitters I
put into the system, I would have to put in one signal amplifier (or
I have 6 tv's that will show the same thing, whatever comes out of the
vcrs or the master antenna. And to do that I had to put in 2 signal
amplifiers. How they will work with cable internet, if I ever get it,
I don't know.
The numbers are pure ratios. They are really loss ratios so the lower the
number the less loss. Whatever the input signal is , the output will be
that many db lower. As I mentioned above the ratio is a log function and
while 3 db is twice or half as much (the spliters may not show the negative
sign to indicate loss), 6 db is 4 times or 1/4 as much depending on gain or
If you get cable internet, usually a splitter is put in so that the modem is
fed with a 3 db loss port. Then if you want more than one computer , you
get a router and run cat 5 cable to each computer or use a wireless router.
Decibels do indicate ratios. 3db loss means 2:1 power ratio. Since
perfection doesn't exist, the loss through a normal 2-way splitter
will be greater than that.
Note that the need for amplification depends on the actual signal
levels, no simple rule will always apply. If needed, an amplifier
should be located BEFORE the cause of signal loss.
I have a similar setup. I can tune any of my TVs to channel 70, to
watch whatever is playing on my main A/V system (although this doesn't
yet include HD). This is switched between cable, satellite, DVD, and
In my setup, the incoming cable first goes to a 2-way splitter, with
one output dedicated to a cable modem (digital cable would require the
same setup), then it's combined with the output of my channel 70+
modulators (for local distribution), then to a distribution amplifier
(really an amp and a splitter in the same package) and the necessary
splitters to reach every TV in the house (as well as recording
devices: VCR, PVR, etc.). Only one amplifier is needed even though I'm
distributing signal to 10 devices (6 TVs, VCR, 2 PVRs, computer video
A cable modem is a 2-way device, and so cannot be used across an
amplifier unless that amplifier is designed to work both ways. The
upstream channel normally uses a frequency lower than any normal TV
replying to mm, im2late wrote:
Actually that is incorrect. The ratings of -7dv, -7db and -3.5 db refer to the
signal LOSS when the signal passes through those outputs. A two way splitter
will lose 3.5 db on each output, but on some three way splitters, one output
loses 3.5 and the other 3.5 loss is doubled on the 2nd and 3rd output (i.e.-7db
signal loss per output.) I would suggest connecting your most "demanding" or
important device to the -3.5 output on the splitter for less signal loss.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.