Hi again Johnboi,

   My stereo I use only has the left and right aux ins too.

Concerning the plugs. I've got some of these and often used to use them, especially for connecting two sets of headphones or some other things. It will probably be fine. The only problem is that when you divide signals, you also change the characteristics of the signal.

I stopped using splitting cables/adaptors as often, although having a look at some info about it, after reading your post, I find that maybe I was being too cautious when talking about splitting "line level" signals, and that using these splitters should be fine. I am no expert in understanding 'Ohm's Law', but I am talking about impedance, voltage and current. Skip this next bit if you want.

Say we were talking not about line ins/outs but an amp to speakers.

If the amp was going to be connected to one speaker (which had an 'impedance' of 8 Ohms), then the amp should not have an output above 8 ohms.

If you "split" the amp's signal to instead go to 'two' speakers (each 8 ohm speakers), and if you wired them up in whats called parallel (which is what a line splitter cable/plug is doing), then as a combined speaker cabinet (i.e. just these two speakers together), it is called 4 Ohm. This means that it is now not going to be safe to plug the amp into it. The amp might suffer damage.

Where I was maybe misguided was with line level.

Most hi-fis (but not all), and other equipment with line (aux) ins, have much higher impedances than the device you plug "into" them. Some people say sources' impedances (i.e. ux2, cd player etc.) should be 7-10 times less than the impedance of the thing you are plugging into (i.e. the hi-fi or monitors) for things to work at their best. Now, if we use the speaker picture, then pretend that your hi-fi and monitors are the two separate speakers that you are now joining together. The overall impedance (monitors and Hi-Fi combined) is going to halve. With speakers and amps this can be a big problem, as the impedances are so close to one another, but when line ins on hi-fis/monitors are in the KOhm (thousands of ohms) area (and devices' line outs are usually much lower) instead of Ohms like speakers, then halving it should still be ok (safe at least).

Sound quality may be affected in terms of volume (I think -6db) and frequency loss, but this might not be too bad (when mixing, you might choose to unplug the hi-fi and adjust the mix just with the monitors - thereby guaranteeing no loss of frequencies when listening to see if there is too much or too little bass etc., and then re-connect the hi-fi to see how it sounds on it later).

I am sorry for the big explanation but it was just to expalain why I originally wouldn't have chosen the splitter - but now think it should be fine.

Also, if my explanation is incorrect, I hope someone with more understanding will correct it, as I wouldn't like to give out unsafe information.

Here is an article explaining impedance concerning home studios:

http://www.soundonsound.com/sos/Jan03/articles/impedanceworkshop.asp

God Bless,

David