Hello,

Please try to edit the file main.js and replace the function testimonialCycle()

function testimonialsCycle() {
    "use strict";
    var $ = jQuery.noConflict();
    $('.testimonial_cycle').each(function() {
        var $self = $(this);
        var container_width = $self.parents('.wpb_wrapper').first().width();
        $('.item', $self).width(container_width + 'px');

        $self.carouFredSel({

            auto: true,
            scroll: { items: 1, fx: 'fade' },

        });

    });
}

replace with:

function testimonialsCycle() {
    "use strict";
    var $ = jQuery.noConflict();
    $('.testimonial_cycle').each(function() {
        var $self = $(this);
        var container_width = $self.parents('.wpb_wrapper').first().width();
        $('.item', $self).width(container_width + 'px');

        $self.carouFredSel({

            auto: true,
            scroll: { items: 1, fx: 'fade', duration:500 },

        });

    });
}

Save the file.

Let us know.

Regards!