Pro Audio Rentals & Backline - Boulder/Denver, Colorado We provide pro audio rentals and backline rental services in Boulder/Denver Colorado, along the Colorado Frong Range, Peak-to-Peak and beyond. Backline rentals for touring bands, venues, schools, churches, weddings, and special events. We offer discounts for long-term customers and package deals. Email or fax your technical rider for a quote, or call 303-258-0563. Sweetwave Audio is your source for backline rentals in Boulder/Denver Colorado.