I put a Propipe on my with the SEPST and Ventilatorm AC on my 2011 FLHR. It sounds Ike a big block CHev especially under power. I know hat you did not want to go the tune it it is definitely worth it.
Without wanting to hijack, what model helmet do you have?
Men's Modular Helmet with Retractable Sun Shield would do the job I had the dealer install the Bose
installed I hook it to the iPhone and isolate the outside world (to some degree) you'll like it. Plus the Bose headset has the most comfortable headphones ever you'll forget ur wearing a full face helmet. At first you will need to get used to put on and take off but it's worth every penny.