Barbecue Tech Tips

Hi, I am interested in the RLX and also looking at the Lexus es. How quiet is the rlx at 55-65mph on new pavement and old tarmac? I'd like decibel measurements.

Altair

Welcome to the board!

You chose a pretty interesting subject.

General db info, no details on pavement type or condition:

Acura RLX

I assume dba scale, found an android app "Sound Analyzer App" that has it for own tests

Enjoy!

Barbecue Tech Tips

I'm not a fan of that website due to lack of info and questionable measurements.

I can only comment on my measurements on fresh tarmac.

My 2014 Scion TC achieves 67-68db at 65mph on fresh tarmac.

2018 Camry xse v6 got 63-64db at 65mph on same road.

With the addition of acoustic windshield and side front passenger glass. I could see that 60db or below possible.

With quiet wheels and noise cancelation like the RLX has, maybe mid 50s.

RLX-Sport Hybrid

Here is a post I made quite a while ago on this topic:

Good Morning! I downloaded a db measuring app on my phone this morning and tested it to see what I showed. Here is what I saw:

• 11db - @ 0 mph, Engine off
• 24db - @ 0 mph, EV mode engaged, no ICE engine, no AC
• 33db - @ 0 mph, EV mode engaged, no ICE engine, AC operating with two bars on the fan speed
• 41db - @ 0 mph, ICE engine engaged, AC operating with two bars on the fan speed
• 44db - @ 40 mph on asphalt pavement, EV mode engaged, no ICE engine, AC operating with two bars on the fan speed
• 52db - @ 40 mph on asphalt pavement, ICE engine engaged, AC operating with two bars on the fan speed
• 58db - @ 60 mph on asphalt pavement, EV mode engaged, no ICE engine, AC operating with two bars on the fan speed
• 61db - @ 60 mph on asphalt pavement, ICE engine engaged, AC operating with two bars on the fan speed

*** There was no measurable difference when driving with the AC on or off which surprised me. I would have expected a few db drop but it did not show that on the app.

vucelick

Here is a simplified reminder on the decibel scale. The decibel scale is not linear, each 3 decibels is TWICE as loud (acoustic energy) or TWICE as quiet. For example 70 decibels is TWICE as loud as 67 decibels, and 73 decibels is TWICE as loud as 70.

So 60 decibels and 61 decibels is a 26% difference

some reverence points:

db
140 Gunshot at close range

120 Loud rock show

100 Shouting at close range

80 Busy city street

70 Normal conversation

50 Quiet conversation

30 Soft whisper

20 In the woods at night

6.5 Mean absolute threshold at 1 kHz

0 Reference level

George Knighton

When Alex Dykes tested the 2018 KC2, he rated Cabin Noise as A+. He quoted 68 decibels on the country road he uses for these measures.

He's a reliable, overly analytical (!!) tester, and if he says A+, I would generally believe it. The road on which he tests noise is not an especially gentle road.

I'd say that where most people go wrong with noise is with the installation of aftermarket tires, or wheels/tires that will provide better handling, but at the expense of a very noticeable increase in noise.

I have a 2014 KC2 and my personal experience is that you wouldn't really need or want a quieter car.

George Knighton

In his review of both the 2014 and 2018 KC2, he mentions how quiet they are.

Many of us on the Short List will remember driving that Pomegranate 2014 pre-production car that was being taken around the country.

Barbecue Tech Tips

I'll try to get around to test driving a RLX non-hybrid. I don't want to deal with the added complexity, since I do my own maintenance and keep my cars for 10+ years.

Altair

》 Great info! I bet scale was weight adjusted for human hearing, ie. dbA, which reduces or increases the db reading based on specific frequencies.

》 using the unadjusted db scale (iirc Z scale) i got my Acura (RDX 2008) to read around 60db, ie MORE than the 43-44 db on the A scale, at idle ( yes mine seems to be idling somewhat louder but not 32 times louder than published info).
So, expect most published numbers to be adjusted to human hearing, to be so low... 2013 RLX@65mph is near the 60 mark,

Before you do the drive test ensure you have the A scale available. After searching on the iPhone apps store, many free applications do not have it, while some do once you pay for the application.

For reference found a primer describing some of these differences:
https://www.cirrusresearch.co.uk/blo...cy-weightings/

Engine temperature, outside temperature, even oil rating may also influence the results. Sampling speed (readings per second) may be relevant in case of unusual sound patterns (could be either higher or lower reading).

Looking forward to your results!

Barbecue Tech Tips

My tests were done with phone app decibel a scale and stand alone meter weight a. The results were marginally different.

andysinnh

I've driven Acura/Honda cars for decades, and the RLX is the quietest I've ever owned and/or ridden in. One thing I've had issues with Honda/Acura vehicles is the sound that gets transmitted from the road to the interior (suspension), and the RLX really seems to quiet that sound transmission quite a bit. When I drive the same roads in my '17 MDX and compare it with the '18 RLX, the difference is dramatic. No db meter, just my ears noticing the difference....

andy

Ken1997TL

The RLX (and 2011/12 RL) have the Helmholtz resonators built into the factory wheels which significantly absorb road noise. 6 dB is a significant amount!

Add in the twin piston shocks along with a significant amount of sound deadening and you get a smooth and quiet ride! My '11 RL has Tein Flex Z coilovers with adjustable damping and I added even more sound deadening

Barbecue Tech Tips

Coilovers don't really help achieve a soft ride, more sporty imo Lexus quiet wheel solution claims a reduction of 10db over a regular wheel.

Ken1997TL

That's true, just stating for facts sake

The springs are definitely stiffer than stock but it's a quiet car despite the aging Yokohama tires. When I get the new tires installed this fall I'll do a decibel test