Sounds like a personal ad I might answer. Don't tell my wife.

 

Quote:
Originally Posted by stevenvillatoro
Quiet. Leather. 21.


Now THAT is funny!!!!!!

 

Nice one!

 

misbe — I have now taken some sound level meter measurements at the driver's position in my TCH (Michelin tires, cloth seats, no moonroof, no NAV), and this is what I find (the red measurements were taken 14 years ago in my 1993 Camry V6 LE):

• @ 50 km/h (~31 mph) in EV mode (ICE off): normal pavement — 58 dBA/80 dBC; smooth pavement — 58 dBA/78 dBC
• @ 50 km/h (~31 mph) with ICE on: normal pavement — 59 dBA/81 dBC; smooth pavement — 57 dBA/77 dBC (58 dBA/88 dBC)
• @ 80 km/h (~50 mph) with ICE on: normal pavement — 63 dBA/84 dBC; smooth pavement — 61 dBA/81 dBC
• @ 100 km/h (~63 mph) with ICE on: normal pavement — 67 dBA/87 dBC; smooth pavement — 63 dBA/84 dBC (67 dBA/90 dBC)
• @ 112 km/h (~70 mph) with ICE on: smooth pavement — 67 dBA/84 dBC
• @ 120 km/h (~75 mph) with ICE on: smooth pavement — 68 dBA/86 dBC

You'll see that my measurements are in good agreement with the Road & Track measurements, and lower than yours. Note that I used "slow" averaging, and because road irregularities add considerably to the noise peaks, I took the lowest quasi steady-state reading in each case. Since some road surfaces are significantly quieter than others, I took some data on both "normal" and "smooth" roads. I show 'C'-weighted measurements in addition to the 'A'-weighted ones. The 'C' weighting curve is flat, whereas the 'A' weighting curve rolls off the low and high frequencies in an attempt to approximate preceived mid-level loudness. This approximation is not very good, and so 'A'-weighted measurements do not represent perceived loudness very well. Making a perceptual "loudness meter" is a very complicated proposition. The 'C'-weighted measurements are not intended to correlate with perceived noise, but rather to show the actual sound pressure level — low-frequency noise dominates the 'C'-weighted measurements. Notice, however, how much lower the 50-km/h and 100 km/h 'C'-weighted measurements of the TCH are than those of the 1993 Camry (partly perhaps because the latter wasn't in overdrive yet at 50 km/h). I don't think these data show how much perceptually quieter the TCH is than the 1993 Camry.

From these measurements it is apparent that road noise dominates over engine and motor noise at most speeds. It is interesting to note the noise measurements that Road & Track gives in their July issue for the $100 000+ Lexus 600hL hybrid [63 dBA at 50 mph (~80 km/h) and 67 dBA at 70 mph (~112 km/h)] are no better than those of the TCH! I'm sure, however, that the perceived noise is lower in the Lexus.

By the way, the decibel scale is used for sound level measurements because the ear's perception of loudness is approximately logarithmic. A 1-dB level change is barely audible; a 3-dB level change is clearly audible; and a 10-dB change sounds approximately like a doubling in loudness. [A change of 3 dB represents a doubling in sound intensity, but not in perceived loudness.]

For the record, I usually listen to the radio at a volume setting of '20' and to (classical music) CDs at a volume setting between '20' and '35' (disc dependent).

Stan

 

Hmmm..... Sometimes I wonder !!??!??! The TCH is ultra quiet, the transition from electric to gas is nearly seamless and whisper quiet (at least from the inside!), the car rides like a Lexus, and people are griping that it is noisy !!!!! Makes me wonder what they would say if they sat in a Porsche which growls audibly, and in an Acura TL, which is DEFINITELY louder! (I can personally vouch for the latter since my wife owns/drives one.) I get around 35-40 mpg and can drive about 500+ miles on a tank of REGULAR gas while the TL requires the 93 octane. The sound system in the TCH is FAR superior to the TL's, which sounds flat ! The steering is so light in the TCH (which some may argue is not really good, but which I say is GREAT since I can drive to NYC and back and barely feel tired!) that I barely have to use one finger to control the car, while I have to be careful not to sneeze while driving the TL , and I can actually eat at a restaurant and ride home in floating comfort, as opposed to the TL which hiccups everytime it hits a pebble in the road, never mind a pothole! I dunno, guys, somehow this discussion seems moot to me.

My 2 cents, and I'll zip it now!!!

 

SPL --

Thanks for the data. I appreciate the feedback.

A question regarding the BO-12to15.pdf file on the top down view of the added coatings. Do you know if the coating is on the underside of the car or on the inner side. I checked in the trunk under the spare tire and found no foam coating. Do you see something different on yours?

 

misbe — I have added some further data and comments to my Post #24 above. I believe that the sound-deadening foam is added on the underside of the body. You'll have to crawl under the car to verify this!

Stan

 

misbe — I have added some high-speed noise measurement data to my Post #24 above.

Stan