Is it better to chant the Hare Krsna mantra loud or is it better hide the mantra?

Expressions researched:
"Is it better to chant the Hare Krsna mantra loud or is it better hide the mantra"

Srimad-Bhagavatam Lectures

As loud as possible. So that others can hear and take benefit of it. There is no secret.

Lecture on SB 6.1.15 -- London, August 3, 1971:

Indian lady: Is it better to chant the Hare Kṛṣṇa mantra loud or is it better hide the mantra? (?)

Prabhupāda: As loud as possible.

Devotees: Jaya! Hari bol!

Prabhupāda: So that others can hear and take benefit of it. There is no secret. It is not that secret mantra, that "I'll give you a special mantra, and you give me $35." (laughter) It is open to everyone. Chant loudly, as loudly as possible. No question of payment.