2 REL Strata Subs and Mono amps

Sunnyboy1956, thanx a lot.

May we know what an amp(s) do you use? I am familiar with certain rumours that, reportedly, some fully differential balanced amplifiers could have serious problems with above-mentioned setting of configuration (ie. red plus yellow wires from the woofer connected to the red output terminal of the amp, while woofer's black wire to the amp's black output terminal).

Personally, I have a piece of Primare A32 250Wpc stereo amplifier planned for that task. The main part of my system is consisted of Krell Phantom preamp (with active crossover onboard) and a pair of Krell Evo-400e monoblocks. This combo is supposed to drive the main speakers, while Primere A32 is planned to feed two REL Gibraltar G1, via high level inputs, as REL strongly recommends in user manual.

Is good idea to ask Primare factory, perhaps? They should know well whether REL's high level input connection method is environment safe enough for power amplifier design employed in their A32..

Thanx once more guys, tips like these may apear as a true paramount for me.

Brownsfan,

My appologise, I obviously missed your advice to ask the amp manufacturer themselves, as also missed to say thank you.

Truly appreciate your input.

Connection of the red and yellow wires to the red output terminal of the amp is fine. Connection of the black wire to the black output terminal of the amp is fine if the amp does not have balanced outputs, and is not bridged.

If the amp has balanced outputs or is bridged, the black output terminal will have a full-amplitude audio signal on it, equal but inverted with respect to the signal that is on the red terminal. If a path exists between the circuit ground of the sub and the circuit ground of the amp, the result of connecting to the black terminal in that situation would be that the signal on that terminal will be shorted to ground, possibly damaging the amp. Whether or not such a path will exist depends on the internal grounding configuration of the two components. If both components have their circuit ground and chassis ground connected together, for instance, that path would exist via the AC safety ground wiring in their power cords, and the house wiring (or internal wiring in a power strip or conditioner, if one is being used) that interconnects the respective outlets.

If the amps are balanced or bridged, connecting the black wire to a chassis screw should be safe to try, and may or may not work acceptably depending on the grounding scheme of the amp. If hum or other issues result, and the amp has an unused RCA input connector, an approach that would definitely work is to solder the black wire to the ground sleeve connection point of an RCA plug, leaving the center pin connected to nothing, and inserting that plug into the unused connector. Similarly, if there is an unused XLR input connector, connecting the black wire to XLR pin 1, using a mating XLR connector instead of an RCA plug, would also be a good approach.

Regards,
-- Al

Rel has the correct wiring for Neutrik plugs on their website I think (or in the manuals) as I found 'em for making my own REL cables...in any case, once you figure out which wire is going to the negative speaker post, I imagine you only need one positive lead per mono amp, as otherwise a single REL sub combines those signals anyway to utilize both channels. I also suggest the "angled" Neutrik plugs as they allow easier placement close to walls...I love those damn Neutriks.

Zormi
My amp is a CJ LP 70S.
Almarg is absolutely correct that the wiring scheme of red+ yellow in the neutrik speaker wires tied to the +(red) terminal of the amp's speaker binding posts and the black to the -(black) speaker post is the way to go in respect of an unbalanced amp. For a balanced /bridged amp check with REL. If I remember the G1 manual covers all scenarios. The input impedance of the G1 is in excess of a 1k ohms and amp damage is not likely.
The G1 is an amazing sub.
Njoy