|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
I'm trying a long run of cable to add an extra TV in a work area.
I may need a cable amp to boost the signal for the 100 ft run, but was confused at the descriptions of such amps as "10 dB," "15 dB" etc.
How does decibels apply to an amplifier???? (I understand the concept of playing one's speakers at 100 decibels.)
TIA,
Bruce
Follow Ups:
Assuming your cable signal arrives at your home at a 0db point, each spltter will drop this signal by Xdb amount. Average splitters will lower the signal 3db on each new connection. As you can see this will add up fast. As you lower the signal you lower the potential quality of picture at each tv. Amplifiers are used to boost the signal up to a point where you can split it up and not end up with poor pictures at each tv. You would be smart to check with your cable provider and see if they supply amps. They do in our area, (Cox Cable). The amps are not costly and should a problem arrise down the road they will not be pointing at your 3rd party amp as the suspect since they may not support it, and in a lot of cases they would even replace a faulty amp if it was bad, if it was the make and model they supply.
Jim,
Thanks. But I still am unclear why "dB" is the correct term here. I've always seen "dB" used to express loudness, so the description of 3dB splitter loss makes it seem like it's losing volume (rather than quality of signal).The practical solution is just to try a Radio Shack amp (with their 30 day return policy) and see if it works, but I was/ am still interested in the terminology.
Thanks again for the input,
Bruce
Hi BruceI recall from my days in telecoms that a loss 3db represents half power. So if you cable gives a loss of 3db over 100ft (for example), you will have half the power you started with.
DB is just a measure of power and need not only apply to sound.
Regards
mark
Mark is correct, (I am in telecom). The term db is a measure of power, and this "power" can be an anlaog signal either video or audio, and also applies to digital signals with video or audio content.
Weird, since 10db is a logrythemic scale. I could only assume that if 10db implies twice as loud, then it'd be a 2X boost.Personally, I've found adding splitters is more of an issue than running long cable lengths. I added one upstream and do notice it a bit on exiting TVs. The one connected to it on a 50' run ahead of the other existing splitters is great.
This post is made possible by the generous support of people like you and our sponsors: