My first Subwoofer, positioning and connections for AV and Stereo use

[mattjax05]

Hi. I'm getting the Wharfdale SW150 which will complete my surround system. I know that using the sub preout on my AV to the sub line level input (left input I hear) is the ideal connection for surround sound but what about stereo?

I use the front channel preouts on my AV to my Stereo amplifier for CD use. Multiple inputs to the Sub is a no no right? So I guess it's either as mentioned above for Surround sound so no sub in use for CD, or connect using speaker terminals on Stereo amp to Sub's speaker input terminals for stereo use but no Surround.

Any other ideas?

My ideal position for convenience is at the front next to either left/right front speakers, sound good?

 

[Anonymous]

Many subs can accept high and low level inputs.

Low level inputs will be the sub pre-out from your AV receiver. This covers your discrete sub channels on surround sources and and bass management the AVR performs to split bass duties away from the main speakers and re-directs it to the sub. e.g. for stereo sources (non bypassed analogue or digital) going into the AVR,

The high level inputs will be for connecting the L/R speaker output of a stereo amp to. Often daisy chaining the banana plugs on the stereo amp speaker terminals, then going to a Neutrik socket on the sub. Here the sub doesn't actually draw any load from the stereo amp, merely takes the signal and amplifies it itself for to drive the subwoofers own cone (for a common typical active sub). With this setup, there is no digital processing to give a smooth crossover from the main speakers to the sub, so you have to manually tweak the volume/crossover on the sub, to ensure things are smooth.You don't want mains/sub being louder than the other, or a big gap in the frequency range, or a big hump where mains and sub both cover a frequency band. This is where the free download software Room Eq Wizard become invalueble, to measure this frequency response and visually graph it.

Of course, if you have it connected to the high level inputs of the stereo amp doing the fronts, this can effect setup for low level input from the AVR. Here, set your mains speakers to be 'small', so the AVR sends no low frequency to them and then in turn no low freq signal goes to the sub through the high level inputs.

A quick look at the specs of your sub, and it seems yours has both high and low level inputs.

 

[mattjax05]

Ok great so now it seems I can have two inputs to the Sub with no co mplications. How is it best to connect stereo amp to Sub then? Should I connect four (left '+' '-' and right '+' '-') speaker cables from the stereo speaker terminals of amp direct to sub or take the cables from speakers terminals to sub? Also I'm a bit confused as to what amplifier will be doing the work i.e the stereo amp or the sub's amp? I thought it would always be Stereo's amp with high level input feeds! And what speaker cables to use? I use QED Silver for speakers will this do as I may have some spare! One more thing, I thought the crossover/volume on Sub is only for when low level input feeds are used i.e they do nothing with HL inputs as you're not using the Sub's amp but I may be wrong? What's Neutrik? Help please. Cheers

 

[Anonymous]

Yep, run a cable from speaker terminals on amp, to speaker terminals on sub. I guess running it from speakers would also work, but I imagine that'll be more awkward due to distances and placement.

The Sub's built in amp would be doing the work. It effectively taps a signal from the amps output.

If you have some QED Silver spare, that'd be more than adaquate.

The subs volume level will probably effect both high and low inputs. I doubt that crossover will (though do check your sub manual). It wouldn't make sense to affect the low leve inputs, as this usually comes from an AVR which has already filtered out the high frequencies. Either way, the volume/crossover are essential for integrating the sub with your main stereo speakers, as your stereo amp can only send the same signal to both. Its up to the sub, to ensure its set to the same volume as the main speakers and freq response meshes nicely.

Neutrik: My BK Monolith sub has a neutrik connector for the high level inputs, essentially a big plug that locks into place on the sub, on the end of some speaker cable that connects to my stereo amp. Just an alternative connection to your subs speaker terminals - essentially does same thing, carries same signal.

 

[mattjax05]

Much appreciated Arfa. You have explained how it'll work very clearly. I will get on with connecting the high level inputs once I've found the spare QED Silver.

Thanks, Matt.