Long wire run

[JamesAMW]

Now that i have a pair of RP 3s with powered subs, my KSW 12 is overkill in my living room.

so i'm thinking of putting it in the den to add life to my baby KEFs on speaker switch 2. this will require a 75-100 wire run off a Yamaha RXV795 dts receiver.

does anyone have any comments or forsee and problems with a run that long?

thanks

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JamesAMW

[WMcD]

I'd like to beg off with an opinion, but I can't erase things entirely. I'm a bit out of my element.

A long run from a line level output, like from an RCA plug, might be a problem. A run like that is supposed to cause high frequency roll off because of the capacitance in the wire. Of course, you're not worried about high frequencies. So it might not be a problem.

On the other hand, is there not an input to the sub to allow it to be driven from the speaker line? That shouldn't be a problem.

Gil

[minn_male42]

I have to disagree with Mr. McDermott in his reply. You are better off running your low level input than your speaker lines. I work in the commercial sound field and low level lines can be run literally thousands of feet without any loss, but 8 ohm speaker runs have limits. 75 to 100 feet should be no problem for the line level run.....

[WMcD]

MM42 has a point.

Very long runs of speaker wire do suffer from losses. This is when there is a speaker type 8 ohm load. The 8 ohm or so load causes current to flow in what is typically thin wire used to make the run. There are IR (current times resistance = voltage) drops in the voltage delivered to the speaker. Also, it may be that the inductance and capacitance of the very long line ruin the response.

On the other hand, I believe the speaker level input to the sub is another story. The input is not an 8 ohm load and is probably up in the area of several thousand ohms. (I'm not certain of this, not having a Klipsch sub to test.)

As a result, the line out to the speaker does not carry any appreciable current and there is no IR voltage drop. So I think it would work. The set up is close to that of a telephone.

In any event, it would not be difficult to experiment. It is cheap, and I think it will work. Worth a try.

Of course it is not uncommon to have, say, a 100 foot run of speaker wire to a remote location with an 8 ohm load (speaker) on the other end. The losses might not be too bad particularly with 16 or 14 gauge wire. If the mains are run off the B switch of the amp and there is the run to the remote room maybe some good results are already realized.

Best,

Gil

This message has been edited by William F. Gil McDermott on 01-08-2002 at 09:47 PM