Wagner Mello writes:

> The pipes are mounted 1" apart and 1-3/4" between ranks.

If the pipe speaks well with the one directly in front of it removed,
I would guess that you need more speaking room between the ranks.
As the pipe in question is the largest in the rank, its mouth is
closer to the one in front of it than the others.

Ideally, there should also be more space between the pipes within
a rank.  That can be achieved without making the organ bigger by
placing the pipes in such a way as to have an even amount of space
between all pipes, so the pipe holes under larger pipes are further
apart than the smaller ones.

Regards,
John Page, UK