Replaced a standard single handled shower faucet with a new pressure balanced version from the same manufacturer. When the diverter is in the "tub" position, noise is typical. Lift the diverter valve stem to re-direct water to the "shower" position and the noise emanating from the valve and associated 1/2" copper supply piping is unbearable. Loudest when the valve dial is in the middle (approximately 50% hot & 50% cold), which is the favored position. Replaced both hot & cold 1/2" copper supply pipes with flexible 1/2" braided hose in an attempt to isolate the valve to minimize the noise/vibration conducted to and through the supply piping. No improvement. Even though there is no abnormal problem in the tub mode, reamed burr from the inside edge of the 1/2" copper pipe that is inside of the diverter valve. No improvement. Replaced diverter valve. No improvement. Insulated entire partition wall between bathroom and master bedroom with sound proofing insulation, including cavity behind access door as well as underside of tub. Marginal improvement. After having tried these various remedies, contacted manufacturer's tech support and described problem in detail, emphasizing that it was a major issue for my wife & I because, as noted, the bathroom adjoins the master bedroom and the excessive noise invariably disturbs the sleep of the person who is trying to sleep in. Suggested that there was a design or manufacturing flaw in the internals of the valve (sharp, inadequately machined edge around an inlet or outlet orifice to/from the mixing chamber?). Was told in so many words that "such is the nature of the beast" and I'll get used to it. Resolved to try another manufacturers brand when we do a bathroom reno; however, in the experience of other DIYers, without naming brand names, is this, in fact, a characteristic of ALL brands of pressure balanced shower faucets? Sorry for the long-winded explanation. Thanks for your time.