going 2.1 (adding the 0.1)

[Dizzy_124dvc]

I have an active sub and a DVD player with no sub output (I used the sub with my shelf system to add the rumble when I watch movies), and I'm planning to get a NAD integrated amp.

Question is, HOW do I feed a signal to the sub? the DVD player has no sub output/mono RCA (unlike the aforementioned shelf system). The sub has high level inputs and outputs though, however, that means I'd need to wire the NAD's two channels to feed the sub first, then wire the outputs to the speakers right? wouldn't this method degrade the quality of the signal, ie pick up noise or reduce warmth in the sound?

[karpiel666]

As long as the connections on the sub are high quality you shouldent be able to notice a difference. If anything it should tighten up mids and lows with the
mains not having to produce low frequencies.

[Zen Dragon]

You should be fine. When you set the sub crossover it acts like a filter. It sends the low frequencies that the sub needs to the sub amplifier and passes everything above the crossover frequency back through to the speakers.
As Karpiel has stated, it relieves the NAD amp from having to drive the lower frequencies which puts the greatest strain on an amplifier as that is where the impedance can really dip and demand the most current from your amp.
Without having to drive the low frequency high current peaks the NAD amp can put more umph into the mids and highs.

[adam2434]

Here's another recent thread about adding a sub for 2 ch:
http://www.polkaudio.com/forums/showthread.php?t=40334

You will only relieve your NAD of bass frequencies if the sub has a high pass filter on the speaker outs. Very often, a sub's crossover is only a low pass filter for the sub, and therefor, the speaker outs run full range.

[Early B.]

Yes, it will affect the quality of the signal, but whether or not it makes a difference is the issue. In your case, probably not.