[Tone Depth]

Frank,

Will your phase inverter circuits option installed in one of your preamps drive a plate amp in a mono subwoofer or in stereo subwoofers from the second set of preamp line outputs?

Wayne is correct.  Many HT processors have a single mono low frequency output.  This is isolated from their normal main stereo outputs and is after some kind of internal frequency shaping circuits.  This permits use of a subwoofer - plate amp with minimal signal processing electronics.

We do not provide that kind of HT processing in our high fidelity stereo audio preamplfiers, both sets of stereo audio outputs are in parallel and are full range.  This assumes that your subwoofer plate amp has stereo line level audio inputs and has the necessary crossover circuit built in to isolate the preamp input channels from each other.

If all else fails, speaker level connections usually work well too, despite my reservations.

Frank

[avahifi]

Correct, the unity gain phase inverter option would drive and isolate the second set of audio outputs on the preamp.

You would need to reverse the polarity at the speaker connections to put the main speakers and subwoofers back in phase if the subwoofer does not have a phase reversal switch.

Frank

[ricmon]

I believe that most modern day subs will not have a set of "stereo" line level inputs. LFE outs from modern multi-channel preamps is a processed signal, combined into a single channel (hence, 5.1, 7.1 etc.) and most will even send the lowest bass signal from the surround speakers to the sub-woofer. Its a processed signal.

'ner

I have been using a subwoofer with my pre (originally a TR-7) since it was new all those many years ago.  It has stereo line level inputs, my current sub has them..In fact every subwoofer I have every considered for insertion into my system has stereo line level inputs.  I would go one step further and say very "audiophile" grade sub will have stereo line level inputs.

Ric

[srb]

In fact every subwoofer I have every considered for insertion into my system has stereo line level inputs. 

The majority of subwoofers have left/right stereo line-level inputs.  Some have an additional separate .1/LFE mono input while some others just have the stereo pair and a switch to select between .1/LFE (internal crossover bypassed) and regular line level (internal crossover engaged).

Some lesser subs have only the stereo line-level pair, and if you want to use LFE, the best you can do is set the sub's crossover to Max to help "get it out of the way".

Some of the exceptions to this are REL and Bryston (and I'm sure there are some others).  The less expensive RELs have only a mono line-level while the more expensive RELs have a left/right stereo line-level pair.

Steve