2 REL Strata Subs and Mono amps

Brownsfan,

Could you publish your advice overhere, anyway? I face a very similar dilema with a pair of REL Gibraltar G1.

Thanx.

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.

Huh..

Primare A32 is fully balanced design, as emphasized on their website, so it seems that I will have to look elsewhere. Safety is of course the most important issue, at least for me..

Thank you all for very insightful set of opinions.

Primare A32 is (was?) planned solely for feeding the REL woofers.

Removing the Primare from the chain basically imply several possible solutions, as far as I can see (I am far from any qualified tech know-how in electronics):

1) simply connect the REL G1 (via Neutric high level input wires) to the Krell Evo-400e blocks, simultaneously with the main speakers, as Al suggested above. Possibly uncomfortable a bit, since Krell has only one par of output terminals. Plus, above discussed possibility of some damage to monoblock amps..? However, this solution ensures reflecting the sonic nature of the main amp(s).

2) connect the REL G1 via low level input, RCA type, which was my natural, initial idea, until I saw the "REL connectivity" section on their website and their strong advice to use the Neutric high level input for best sonics. I can still use REL's RCA low level input to connect the woofer directly to the Phantom preamp low-end RCA output. In this case, any complications with the power amps should be eliminated, but benefits from "reflecting the nature of the main amp", as REL recommends, will be lost. BTW, in this case, I am a bit confused (since have two REL G1s) whether to put the RCA cable from preamp into the right or into the left RCA low level input of the woofer? Al, which one is the accurate, please..?

3) keeping the option with Primare, but connecting the black wire to the amp chassis, instead of black output terminal. Unconfortable a bit, but safe for amp. Krell power amps' sonics "lost" for the woofers.

4) employing another big stereo Krell (btw fully balanced as well) instead of Primare, which will keep the Krell sonics for woofers. Too pricey solution, out of my reach.

5) employing another stereo power amp, which is not balanced design. Krell's sonic nature definitely lost for woofers, but all other problems eliminated. Good that this one may be relatively modest in power and price - as Al elaborated above, relative lack of power may be compensated by putting the woofer's yellow wire to the red amp's terminal, plus additionally reinforced utilising woofer's own amplifiers.

Great inputs Al, anyway, thank you very very much. You truly deserve all positive reputation from us fellows overhere.

Very nice, guys, I learned a lot from you last 24h...

Al, I think I was told everything I needed in this particular situation that I simply did not know. Tnx once again. I am gonna write to Krell these days...

Vladimir, my main speakers right now is a pair of B&W 805S, but this is a temporary solution rather than long-term choice. When budget allows, I will probably go with higher class speaker - Focal Utopia Diablo, for instance (use to own Utopia Micro Be - fabulous speaker), maybe Dynaudio Confidence C1, but - addressing to your question - whatever I choose, it will be a standmount, almost for sure (room size issue). Certain possibilities to try Magnepan 3.7 pannels, which deeply impressed me, but I am sceptical due to room size (15x15).

Wow Vladimir..

Nice idea with C1 MkII, already under consideration. I know them well, since I use to own original edition Confidence C1... In fact, I owned both Utopia Micro Be and Confidence C1 until the end of 2008, simultaneously. Two different worlds, each one impressive on his own way... I now prefer a bit the Utopia Diablo because a slight edge over Dyn C1 in mid/high clarity and detail rendition. Bass aside, this is where C1 excells, but RELs defeat that area as a serious issue. Price wise, I have a great dealer from Belgrade, Serbia, which is able to bring me a pair of Diablos including dedicated stands for the same money as pair of C1 MkII without stands at another dealer. But, price doesn't matter too much... differences between the two simply not prominent enough to have any serious impact on decision.

@ Vladimir

Yes, I've just checked the Gibraltar G1 manual, and they indeed give on the p. 12 the same advice Al gave to me above (if power amp is balanced ie differential).

What they don't say is what to do in case of having two subs (stereo sub system) and balanced amplifier, as I have... Following strictly their user guide (bottom half of the p. 12), an average audiophile in my position will normally connect even fully balanced amp with two subs, the way REL suggests, and probably damage the amp.

Very insightful thread, for me at least.. Grateful to all of you.

Happy New Year to all, lots of music!