Decibel of a turbine engine

[Bradz]

We have a 90 DB test in Illinois at idle. I have always wondered how loud in decibels a turbine boat would be at idle. At speed they seem much quieter on the water. Yet at the docks they have a very high pitch sound and it seems very loud. Anyone actually tested a turbine boat?

[BBB725]

On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB. Here are some common sounds and their decibel ratings:

Near total silence - 0 dB
A whisper - 15 dB
Normal conversation - 60 dB
A lawnmower - 90 dB
A car horn - 110 dB
A rock concert or a jet engine - 120 dB

I assume the 120 is a WOT

[Bradz]

I have read that a jet taking off is 120-140 DB like your post says. I am actully wondering what the DB of a turbine is at idle. I am dreaming someday of owning a turbine. But if the noise cops are going to stop the fun... I have a feeling it is too loud as it seems loud at the docks, but wondering if high pitch registers differently on a meter not under load.

[rchevelle71]

I have read that a jet taking off is 120-140 DB like your post says. I am actully wondering what the DB of a turbine is at idle. I am dreaming someday of owning a turbine. But if the noise cops are going to stop the fun... I have a feeling it is too loud as it seems loud at the docks, but wondering if high pitch registers differently on a meter not under load.

Move to FL, Turbines dont seem to bother the cops around here

[Davidmnc]

Move to FL, Turbines dont seem to bother the cops around here

It's a little warmer too

[boostbros]

a turbine is loudest at ground idle and quietest at full power the screeching you hear at idle is the bleed bands wide open what happens is the sides of the case around the rotating blades open to allow air to escape or not get forced thru the combustion chambers too much air and little fuel would blow the fire out as the bands close and all the air is forced thru the engine it gets very quiet almost the exact opposite of a gas engine

[Pete B]

http://www.gcaudio.com/resources/howtos/loudness.html

[TurbineDood]

Boostbros gave a pretty good description of how the noise changes with rpm..

At idle (usually 45% to 70% rpm depending on the model) most gas turbine engines have a high-pitch whine that can be real annoying. Once an engine runs up to the higher rpms there is more airflow that changes the sound.

I run a T58 gas turbine in my Cat and at higher rpm the sound is more of a 'whoosh' compared to idle that has more of a shrill 'whine'.

The few models of jet engines that use 'bleed bands' have their own characteristic sound.

Generally gas turbine engines run quieter than BBC motors with headers. I say 'generally' because there's always an exception.

TurbineDood

My turbine powered boat:
www.TurbineFun.com

[htrdlncn]

Besides most water DB laws require the meter to be placed a few feet directly behind exhaust outlet to get the proper reading,Id love to see them try that on a turbine..

[dykstra]

Besides most water DB laws require the meter to be placed a few feet directly behind exhaust outlet to get the proper reading,Id love to see them try that on a turbine..

I was thinking the same thing!