The Houston Rev It Up video sounds and positive responses
made me reach for my C&D comparo where at full throttle and idle
the dBA readings achieved average and 70 mph cruising only 1 dBA higher than average. Of coarse it is the turbine like sound
and free-reving that make it so enjoyable. Most of the engineering is to eliminate as much of the sound as possible.
The engine rpm @ 60 mph in top gear is said to be 3100.

Here are SIX technologies that deliver passenger comfort with low intrusion of vibration, wind noise, etc:
1.)ist time use of counter-rotating gear & dynamic balanced rotors.
2.)mode control panels on bottom of car
3.)straight (from side or top) line pwertrain layout
4.)lengthened engine & diff. mount spans (significant vs. RX7)
5.)no floor mount drive shaft support
6.)lengthened multi-link (5) rear to a six rubber mount
stiff subframe based suspension. up front strong chassis subframe.

Now go to thread "Houston Rev It Up" and enjoy those engine sounds! Thanks Eccles.

 

By the way, I forgot to mention that both front windows were fully down during that run, thus increasing the aural enjoyment.