1st set of woofer/coils I replaced, a thin sheet of plastic went into the gap with the coil, centering it (like the paper plate mentioned, After surround glue is dry, simply remove it.
https://reconekits.com/
2nd time, supplier’s method: simply pumping the cone with your hand, speaker on it’s back, when the adhesive is still pliable. his adhesive drying time is designed for this.
https://www.simplyspeakers.com/simplyspeakers-youtube.html
the coil/cone naturally center themselves, if off center, you will feel/hear the coil ’rub’ on the side of the gap it moves in/out in when you pump it by hand.
https://reconekits.com/
2nd time, supplier’s method: simply pumping the cone with your hand, speaker on it’s back, when the adhesive is still pliable. his adhesive drying time is designed for this.
https://www.simplyspeakers.com/simplyspeakers-youtube.html
the coil/cone naturally center themselves, if off center, you will feel/hear the coil ’rub’ on the side of the gap it moves in/out in when you pump it by hand.