Dave, I've quickly gone over your new posts and just a couple quick comments. Yes, Dean(crunch)has indicated his preference for a vertical center speaker and during the seven years I've been here I've pointed out their advantages numerous times.

Your difficulty with finding a mode for using the sub with the mains in 2-channel play shouldn't be, since the regular stereo mode(not direct)sends signals to the sub below the crossover set when the mains are set "small".

As far as making poorly recorded material sound less offensive, I found in the past that reducing the upper midrange/lower treble area around 3-6KHz(on a receiver with variable crossovers)helped somewhat. On your 1909, using the manual equalizer to drop that area a bit might help on some recordings. Since bad recordings sound worse the louder the playing level, the best cure may be to listen to them with the sound level set to about 30dB(assuming that your listening room noise floor is higher than that).

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Enjoy the music, not the equipment.