hbox->pack_start (*_spin, false, false);
hbox->pack_start (*manage (new Label (_("dbFS"))), false, false);
get_vbox()->pack_start (*hbox);
hbox->pack_start (*_spin, false, false);
hbox->pack_start (*manage (new Label (_("dbFS"))), false, false);
get_vbox()->pack_start (*hbox);