Karthick's greatest encouragement and support have been his parents Sri. E. V. Subramaniam & Smt.Padma Subramaniam. Karthick's father was a visionary in the sense that he was far ahead of his times and predicted things for Karthick and what ever Karthick is today is all because of his father Late Sri. E.V.Subramaniam, who believed strongly that his son, would become a skillful performer. He encouraged Karthick in each and every move. Affectionately called 'EVS Mama' was a pleasing personality to all Karthick's friends and was admired by all. He continues to bless Karthick from Heaven.

Karthick's mother, Smt. Padma is a good vocalist, having studied at the Thiruvananthapuram Music College and Central College of Carnatic Music, Madras. She has given vocal concerts, also sings for dance recitals frequently, apart from training students at home. She enhances his compositions by her deft changes. She is the source for Karthick’s ‘Sangeetha Gnanam’.

Karthick's loving wife Anjana is a perfect homemaker and takes care of all his assignments. An understanding teacher, she trains students in all subjects at home. Anjana was mainly instrumental in Karthick finishing his doctorate. Anjana has a good ear for all kinds of music and provides good encouragement and support in all his endeavors and is an excellent critic. She gives suitable suggestions at appropriate times to help him grow in strength and stature. She takes the full responsibility of the children so that Karthick can concentrate his artistic pursuits.

Karthick's son K.Sarvesh is a most fanatic rasika of him and the most obsessed and possessive commentator. He wishes him ‘Good luck' whenever Karthick starts for a concert or a recording and greets him with a big smile whenever he returns from a concert. Sarvesh is doing his 2nd Standard in Padma Seshadri Balabhavan Senior Secondary School, K.K. Nagar. He learns Mridhangam from Poongulam Sri.Subramanian and Vocal from Sri.S.P.Ramh. Sarvesh is a keen participant in all school cultural events. He has already won many awards from the school.

Karthick's three-old little daughter is named K.Sravishta who smiles big at her proud father, to convey him further fortune. Sravishta (which means ‘better than the best’) is now doing her Pre-KG in Padma Seshadri Balabhavan Senior Secondary School, K.K. Nagar. Sravishta seems to be a potential artiste with an intense sense of rhythm and music. She is the world’s youngest fanatic to Superstar Rajnikanth’s hit-songs.