Karaoke Forums

+1 as usual letitrip says it right.

_________________
Jeff Wheeler, moonlight DJ/KJ

Ok I mixed two posts, one where someone said they were using powered speakers who I thought was the origional poster (but was not), the initial question where they were using SPEAKER cable.

Sure it is not the right thing to do, and XLR is is the right cable to use to a powered speaker. BUT using long SPEAKER cable would pick up a humm and that is what the OP said they were using.

AND XLR cable is shielded that is a pair of wires INSIDE OF another wire and that wire is the shielding.

Let me add a thing about speak-on cables. They hold up over a long period of time. Night after night of plugging and unplugging cables can cause wear and loose connections, speak-ons twist and LOCK into place.

_________________
Good music, good friends, howling good times!

The reason balanced connections are resistant to noise is a technical trick. They really aren't, but there are two signal conductors ("hot" and "cold") which will both accept the same noise. The "cold" signal is electronically subtracted from the "hot" one, which eliminates the noise at the receiving end. This even works if you have an unbalanced send on a balanced cable into a balanced input, like a cheap (Behringer/etc) AUX send out to a monitor amp.

_________________
Jeff Wheeler, moonlight DJ/KJ

Hi.
I read your post, and suggest you take some measurements when demoing cabs. I am thinking to increase the cab size and want to implement the LAN connectivity with different speaker enhancement for the whole cab.
So whether there is any other wireless + speaker cable accessories to be deployed on to my system.

_________________
haut-parleurs

Actually, typical balanced signals are done in a differential signal method, including XLR cables. What you do is, you reverse the signal and send it over the second line. Because the signal is now twice as high when combined (for example if the signal swings 0 to 5V, inverse would run from 0 to -5V, thus -5 to 5V swing = 10V), you see a lot less noise and you extract a stronger signal at the end. This is an old transmission line trick to increase the cable length or immunize against the noise. Transmission method was my major in college so I know a few tricks.

_________________

Seize the day and SING!!!

Wow you both found creative ways to describe the same thing. However, eben you make it sound like a signal to noise ratio thing, which it is not. Use of balanced lines does indeed cancel the noise out, not just create a lower noise floor by providing a stronger signal. When the signal reaches the differential amplifier in the receiving end, the two out of phase signals are brought back into phase and summed. This action causes any noise induced over the line to now become 180 degrees out of phase and therefore cancels itself out when summed. As you noted, this does result in a 6dB headroom gain.

_________________
DJ Tony
Let It Rip Karaoke

What I was explaining was not noise canceling, I was explaining the better signal through longer transmission. Depending on the transmission methods, you may or may not sum the signal for noise rejection. Sometimes it's done and sometimes it's not, depending on the signal method. For XLR signals, the differential method is used to increase the length of the transmission as well as some noise suppression of the signal. If the cable is well shielded, the noise is not really a big factor, sometimes impedance mismatch creates some signal reflection, again the differential signal will increase the signal strength so it's more accurate.

Differential is not only used for XLR but many other signals, for example between the computer and the hard disk drives.

_________________

Seize the day and SING!!!

If i had to run a long distance with 2 different size cables

Ex. 50 foot 10 gauge and a 30 foot 12 gauge. I would hook up the 10 gauge cable first and then run the 12 gauge the rest of the way. Even though there will be a slight power loss you are still not losing as much with the amount of 10 gauge you are using before it goes through the 12 gauge. Just like running a fire hose from the hydrant. They go from big to small.

If you are talking about a single 80 foot run from amp to speaker, it does not matter if you put the 10ga closer to the amp, or the 12ga. This seems counter-intuitive until you realize the wire resistance matters on both the + and - conductors, and the amp output terminals form a circuit through the speaker voice coil.

If you have a cable run to one speaker, and the a second speaker paralleled onto it, you would be correct that it is better to use the heavy-gauge cable between the amp and the first speaker.

The fire hose analogy doesn't "hold water" here because the hose is emptying water out at one end. The electrical circuit is end-to-end from the amp + pole, through the cables and speaker, back through the cables on the second conductor, and finally to the amp - pole.

_________________
Jeff Wheeler, moonlight DJ/KJ

If i had to run an extension cords 100 feet i wouldn't use my smallest gauge wire first and work up to the biggest. The small one would get very hot before the larger one. Heat equals resistance and that is a drop of power.

Just like a water hose if i wanted to get water anywhere. Transmission lines are bigger than house lines.

Last I checked we were talking about AC power here, there's no such thing as + / - (or at least it's completely irrelevant) in AC power. There isn't a return path, it's alternating current. However the important part of your point that is correct is that it doesn't matter which cord you put first or second, electricity does not behave like water. Either way there's going to be the same amount of resistance in the two cords and the same level of voltage loss and heeat generated.

_________________
DJ Tony
Let It Rip Karaoke

I thought he was talking about speaker cables, so I used that terminology.

_________________
Jeff Wheeler, moonlight DJ/KJ

never mind I'm a moron, somehow I got confused between this thread and something else I was reading and thought people were talking about the extension cords between their active speakers and power supply.

Now back to your regularly scheduled programming.

_________________
DJ Tony
Let It Rip Karaoke

Way to eat crow Rip!

_________________
KingBing Entertainment C'mon Up! I have a song for you!!! [font=MS Sans Serif][/font]

Hey, I'm not above admitting when I'm wrong.

_________________
DJ Tony
Let It Rip Karaoke