16 Channel Recording VU+ DUO2?

Hello guys/girls

First off I am sorry if this has been discussed before but I have searched and could not find an answer. If so please link me to the thread and admin close this thread.

I am looking at getting an VU+ DUO2 box but a cannot seem to find exact details on the 16 channel recording, please help as this is a attractive feature?

From what I have found I understand that you need an quatro LNB and x2 DVB-S2 dual tuners on the back of the box. This then gives you the 4 LNB inputs.
I also understand vaguely that to achieve the 16 channel recording capacity, the channels being recorded have to be on different quadrants of the signal spectrum - hence why people seem to say that to get 16 at once must be ‘perfect conditions’

What I don't understand is that on a Sky box (only using as an example as its what I'm used to) there are 2 inputs, this allows you to record one and watch another, or record two but you must watch one of the recordings while recording.
Therefore theoretically with 4 inputs you should be able to record 4 at any given time - Correct?

How is 16 possible with 4 inputs - assuming the ‘best conditions’ for arguments sake.
Are these boxes somehow able to record 4 programmes per tuner and if so, how?

Finally does that mean with only 2 inputs you can record up to 8 under the right conditions?

Many thanks,
D

Okay from your explanation I now understand why I keep reading people saying about the 'ideal scenario' of the channels being on the same frequency / transponder.

To clarify, is it the VU+ box's ability that allows you to record multiple channels that are on the same frequency/polorization per one tuner as opposed to a sky box that only let you record one channel per tunner?

Eg. On the VU+ duo2, record itv, itv2, itv4 on LNB1 / bbc1, bbc2 on LNB2 + E4, Channel 4 on LNB 3 - so 7 programmes at once?

I know for a fact that the sky box only had the capability of recording a maximum of two programs at any given time.
With 2 tuner inputs on the rear you can either record one and watch another OR record two but you must watch one while recording.

This limitation is part of the reason I want to swap to the VU+ box.

As far as my example above of a recording scenario on the VU+, is my thinking correct??