Let's play "How loud is your truck?" (1 Viewer)

[FJ40RobQ]

Cool. I'm going to try that app. Looks like it's called Decibel X on the Apple App Store. It's also displaying dB across the audible frequency spectrum, which is really useful. If you have your phone mounted where you can watch how sound pressure increases as your speed increases in certain frequency ranges, it would be a good indication on the things that are really contributing to cabin noise pollution. I bet it can reliably identify wind noise, for instance. In my truck, when I hit about 45mph it's as if someone flips a wind noise "on" switch.

I didn’t think about it that way. I’ll have to figure out a good mount first and then find a good place to mount it. Thanks for the advice!

 

[sogncab]

I wonder how accurate a phone really is for measuring this stuff?

Might be shockingly accurate.
Might also be useless.

 

[gmac]

1982 Troopy
Cheap Floor insulation on entire floor
Original floor matt with holes and heavy duty rubber matts on foot wells
New 33x9.5 Kenda RTs
60 mph
Hard Top
Not 100% sure on the gearing ratio (Aussie model). I believe it's geared lower than the american models.
77.6 to 78 dB

 

[fyton2v]

I didn’t think about it that way. I’ll have to figure out a good mount first and then find a good place to mount it. Thanks for the advice!

Apologies, I didn’t mean that you, specifically, should do it. . It was a general “you”. I’m going to use that app and see if it helps identify noise source over the weekend.

 

[fyton2v]

I wonder how accurate a phone really is for measuring this stuff?

Might be shockingly accurate.
Might also be useless.

It’s probably not very accurate but it may be similarly inaccurate for everyone, so the comparisons may be OK.

You have me thinking about the effect phone positioning will have on the results. Sitting on a seat, vs by your head, vs by the dash are going to result in different readings. Probably. I think. Meh. This isn’t science, I think we’ll see an interesting trend from the rigs with sound deadening material installed.

 

[WildernessRimFab]

I wonder how accurate a phone really is for measuring this stuff?

Might be shockingly accurate.
Might also be useless.

Fair question. I agree with @fyton2v, I think these relative comparisons are ok.

If you have an iPhone (I don't) the National Institute for Occupational Safety and Health (NIOSH) sound level meter app is very accurate.
"Accurate within ± 2 dBA; tested according to standards in a reverberant chamber at the NIOSH acoustics laboratory"
NIOSH Sound Level Meter App - Noise and Occupational Hearing Loss | NIOSH | CDC - https://www.cdc.gov/niosh/topics/noise/app.html

The decibel scale is logarithmic, so a difference of more than a couple decibels is very significant.

Sorry to nerd out for a minute but it is relevant to this discussion.

 

[sogncab]

I wondered about placement having an affect as well. I didn't run the app long, but considered throwing it in the phone holder. I'm guessing the vibration through the mount would have an impact. Especially in mine, that four cylinder diesel rattles.

 

[middlecalf]

Oooh, love the acoustics tech! BTW, a 3db increase in SPL is doubling the sound level.

1963 FJ45L-P SWB fixed top, F135 with stock driveline, 7.0-15LT STA Super Traxion bias ply tires (~600 miles), small rubber mats on each side of tranny hump, no roof liner, windows closed.

Gravel washboard road, 20mph, 2nd gear RWD only, ~1500rpm

Paved road, 40mph, 3rd gear RWD only, ~1500rpm

Paved road, 50mph, 3rd gear RWD only, ~2000rpm

Wish I was a better singer

 

[fyton2v]

"Wow, those STA tires can really sing!"

 

[thatcabledude]

Haha “Loud singing”



^My topless, doorless, v8 40 on swampers

 

[thatcabledude]

It’s actually not bad at all really. I should try that app.

 

[jmylie]

77 FJ55, 56 to 60 db's at idle.

Got it to around 50 and was pushing 80 dB's.

MT tires don't help.

 

[fyton2v]

Took some readings with that other dB meter app. I was driving on a decent asphalt road (not very smooth but not bad) with the phone held sorta around the center of the cabin. Reading are from idle, 30, 45, and 60 MPH. I believe tire noise is the dominant sound, kinda occupying the 100-300Hz spectrum. Engine/gear noise seems to make a difference above 300Hz to maybe 600Hz. Those are guesses.

0 MPH at Idle

30 MPH

45 MPH

60 MPH

 

[iliketrucks]

BJ44
•Axle gearing should be stock (~4.10), 4 speed transmission
•very worn 30x9.5 mud terrain tires
•IDI B series turbodiesel
•stock exhaust
•crappy weatherstripping, not much for insulation just thin rubber floor mats

79 dBA at 40 MPH, 83 dBA at 60 MPH. I thought there would be a bigger difference in noise between those 2 speeds. Also I measured 69 dBA at warm idle in the cab. Measurements outside the vehicle (20 MPH drive-bys in 2nd gear) were about 80 dBA. I'm excited to see what happens with new tires (same size), a 2.5" exhaust with straight through muffler, and a 5 speed - I'll post updates as these things change.

 

[sogncab]

Numbers without context are useless. I just used the google machine and searched for "Safe Sound Levels" and came up with this graph. (Amongst many others)

I want to measure my 80, and my F350 and see what those are at as well. I'm curious.
Sitting in my office with a cabinet shop wailing away on the other side of the wall, I'm at about 60db. When nobody is running equipment, I'm at about 40db.

 

[sogncab]

My 80 is way louder than I thought.

Really dumb mud tires. Plenty of air leaks and full exhaust.

 

[sogncab]

F350, also much closer to the 40 than I would've guessed.

 

[archie73]

Just throwing this out there for posterity. I was getting 90 db using the same app on my iPhone 14. That was worn out 35 bfg mt’s, full length bikini top at 60mph. I finally bought new 35” Geolanders and they are significantly quieter to my ear. However, the app still registers 90 db. I tried moving the phone around the cab, but got the same reading. I stopped the truck and turned it off where all you hear was birds chirping- phone read 40 db!!!

 

[brian]

2f, old marks header, 2.5" exhaust, 33 ko2s

 

[fyton2v]

That’s quiet! Or the roads around you are incredibly smooth.