Welcome to the world of a highflow intake. All intakes make alot of noise because they are designed for performance rather than comfort. Flowing as much air as possible as smoothly as possible takes priority over being quiet.

The stock intakes are much more restrictive with loops and of course the resonators, but those resonators help keep the intake muffled. By taking those out completely, you'll flow more air, but you'll create a racket when on the gas also.