1. Try swapping the speaker cables only.
2. Measure the exact distance from each speaker to your head where it would be when you're seated.
3. Get yourself an SPL meter and check both speakers are matched by measuring the same frequency for each speaker individually.
4. See if you can find a copy of 'Best of CHESKY' Classics & Jazz and Audiophile Test Disc - Volume 3. They have some microphone techniques on that CD that should help with locating center vocals. Or something similar to this type of CD.
2. Measure the exact distance from each speaker to your head where it would be when you're seated.
3. Get yourself an SPL meter and check both speakers are matched by measuring the same frequency for each speaker individually.
4. See if you can find a copy of 'Best of CHESKY' Classics & Jazz and Audiophile Test Disc - Volume 3. They have some microphone techniques on that CD that should help with locating center vocals. Or something similar to this type of CD.