n-vi and subwoofer cable

John
That's a good question as there's only one phono out on my n-Vi and my sub has 2. Guess its somthing to do with the fact that the sub's signal comes from the 'bass-mix', anybody know?

Your sub probably has stereo phonos so that it can be used in a 2.1 stereo system.
Under these circumstances you'd have to set your rolloff and volume on the sub to match your stereo pair, as there'd be no DSP to stop the sub from reproducing the same bass as the speakers... it'd fatten out the mid-bass and sound horrible.

Running from your n-Vi the "bass-mix" system is responsible for sending two things down your mono sub-cable.

First and foremost the LFE (Low Frequency Effects), or ".1" of 5.1 is piped down this.
That's the reason the sub's there in the first place. A true 5.1 speaker package utilises 5 identical full-range loudspeakers to deal with the main 5 channels.

Secondly, and because most 5.1 systems have anything BUT 5 full range speakers, the dsp routes to the sub any bass that any of the 5 main speakers can't handle.

As your sub doesn't have a dedicated LFE input (which would bypass the rolloff frequency settings), you'll need to set the rolloff dial to max as the n-Vi will be doing crossover duty.
Connect to only one phono socket (I'd use the left channel), and use both the sub's own volume control along with the n-Vi's level settings to achieve good bass. Hint... neither of these should be at maximum.

When you play a cd in the n-Vi (or listen to DAB) then the Bass-mix function will run through the DSP and leave your sub working alongside your stereo pair. If running an analogue signal into the n-VI then bear in mind that the DSP is not being used, and therefore nor is "bass-mix">

If you want a sub that works in both modes then you need a sub which has both a dedicated LFE inoput, and can take a "high level speaker input"... in this case run some cables from your speakers to the sub (that way you won't upset the n-Vi by making it think you're running two pairs of speakers in parallel.

A sub of this type is much more difficult to set up when connected this way, but ultimately more satisfying as you get sub-bass on any source, in stereo or 5.1


Hope this helps!

Mike
Yes that makes perfect sense, thanks for the clarity. I'm not using any analogue, and I had found through trial and error the settings you recommend do in fact give the best results.

Thanks

will stick to one input on the sub, have ordered new cable from mark grant, to see if it makes any differance, am using a mk vx-100 sub

Just looked for the spec on that sub....
Stereo RCA inout only, left channel for Mono/LFE input.... No high level speaker input.

With an N-Vi and this sub then you will only get the sub moving using digital sources... eg DVD, DVD-A, CD in the n-Vi (not via the analogue inouts on a separate player), or digital feeds running into the n-Vi.

On the plus side that does include PCM stereo.

On the minus side, if your n-Vi ends up a hub for analogue sources (turntable etc) then your front stereo speakers will have to stand on their own two feet.

If they're not man enough for the job (don't know what you've got) then you'll either need o invest in new speakers, or a new sub with high-level inputs.

I'd take speakers....
Far too many AV systems have namby-pamby little boxes at the four corners sold on the strength of getting the sub to do all the hard work....

As someone who's been listening to 5.1 at home for nigh on 9 years I'd steer as far as possible from the THX/MK ohilosophy of "bas comes from here, midrange and treble are in these boxes"...

PS, apologies for the chronically bad "tyoing" in the above post... heavy night last night

read on an earlier post if i feed a digital signal into tne n-vi, then it will out-put dpl11 so surely the sub comes into play ?

quote:

With an N-Vi and this sub then you will only get the sub moving using digital sources... eg DVD, DVD-A, CD in the n-Vi (not via the analogue inouts on a separate player), or digital feeds running into the n-Vi.

On the plus side that does include PCM stereo.

Or, to put it another way, yes!

If the DSP can get involved, then it will feed the sub, in 2.1 stereo, DPLII, NEO6, DD or DTS.

mike, as long as the sub works from my optical feed from my telewest tv drive, then its fine for me, as i do not intend to plug any thing else into it, as i said i read on an earlier post dsp works from sky+ via optical so should work with tv-drive

Spot on!