I do Music recording and Video edit. I need my mac pro low noise as possible. That what. And My cpu heatsink temp seem a to high when I edit video.
I assume you are talking about the cMP (e.g. 5,1). The nMP should be extremely quiet and good enough for music production.
AFAIK, a good air cooler can be very quiet or even quieter than water cool. The pump in a liquid cool system is not that silent.
I do video editing on my 4,1 as well, the fan is not that noisy, CPU core temperature stay at around 73-76C, heatsink usually around 60C. If your heatsink temperature is high, which is a good sign that the CPU's heat can actually transfer to the heatsink. And as long as the heatsink is clean, the fan shouldn't need to work too hard to cool down the CPU (unless you have dual 130W CPU, that may require the fan to work harder than normal). My single W3690 system rarely need to spin up the fan to >1500RPM. And even though I won't call my cMP silent, but sure is a very quiet machine (even under stress).
The native fan profile may be a bit noiser, but you can always setup your own fan profile to reduce the noise and avoid overheat. I personally setup a profile that evenly spin up all fans, rather than heavily rely on the boosters. Let the intake / exhaust fan spin a bit faster and avoid the booster run at high RPM works very well on my 4,1. When my cMP under stress. The intake / exhaust spin up to about 1100RPM, and booster around 1300. Which is audiable, but not bad at all.
If you need a very silent environment, may be you have to locate the cMP a bit further away from the mic. Or use some noise absorbing material to "isolate" the cMP. I am not an expert in this area. But mod a cMP to be liquid cooled for audio production sure is not a good idea. That's way too much have to be done. And high risk of damging the Mac Pro. If you really need a silent machine to do the job, and macOS is a must, and you don't want to buy the nMP (assuming all other Mac is not powerful enough). Then the best way to achieve that is actually build a very silent Hackintosh. That's the easiest and most cost effective way to achieve what you need.