We extend the results obtained by E. Ntienjem [23] to all positive integers. Let N be the subset of N consisting of 2 ν 0, where ν is in {0, 1, 2, 3} and 0 is a squarefree finite product of distinct odd primes. We discuss the evaluation of the convolution sum,The evaluation of convolution sums belonging to this class is achieved by applying modular forms and primitive Dirichlet characters. In addition, we revisit the evaluation of the convolution sums for αβ = 9, 16, 18, 25, 36. If αβ ≡ 0 (mod 4), we determine natural numbers a, b and use the evaluated convolution sums together with other known convolution sums to carry out the number of representations of n by the octonary quadratic forms a (x 2 1). Similarly, if αβ ≡ 0 (mod 3), we compute natural numbers c, d and make use of the evaluated convolution sums together with other known convolution sums to determine the number of representations of n by the octonary quadratic forms c (). We illustrate our method with the explicit examples αβ = 3 2 • 5, αβ = 2 4 • 3, αβ = 2 • 5 2 and αβ = 2 6 , .