I find the lack of a change to engine sound with power on the J41 rather disconcerting. You advance the power levers for takeoff and there is no aural cue at all. I've never been anywhere near a real J41, but flightdeck videos on youtube indicate there is a sound difference due to the change in power at a given RPM. Is this a limitation of FSX?Kevin

Hi Kevin,We have spent alot of time making sure the J41 sounds are very close to the original - I think you are getting confused with the levers in the cockpit! The left levers are called the "throttles" and these control the pitch angle of the propeller blades - moving them forward causes the airflow sounds to vary. The right levers are the "condition levers" - these control the RPM of the engines, pushing these forward makes the sound you are expecting. Have a little play of the combinations and compare them to youtube videos and see if its any better?!

Yes. I'm afraid to say that we've all been "conditioned" by flight simulator to believe that any change in the throttle results in a change in engine sound... This is ONLY TRUE for Fixed Pitch Propellers and Turbine Aircraft (Turbojet, Turbofan).With a anything with a constant-speed propeller (this includes turboprops, as well as the constant speed pistons)... Once the propeller is "ON SPEED" the sound of the propeller, and therefore the engine sound you will most likely hear does not change. As long as the governor is controlling the propeller within its operating range (ie the blades have not hit the pitch stops) there will be no AUDIBLE change in power. A keen ear could hear a change in power in a free turbine type aircraft (PT6 or PW100 for example). But all you are hearing is the CORE of the engine accelerating and decelerating. That's why you'll hear the whine of the engine change, but the drone of the prop remains constant.The propeller will maintain its RPM through the propeller governor. This is because there is no physical connection between the propeller and the engine. It is only known as a "fluid coupling" much like the automatic transmission in your car, but using air, not transmission fluid. In fact... The propeller on a PT6 or even a Dash 8 for that matter can be HELD IN PLACE and the engine can be started. The ATR series and Saab 340 series of aircraft use this system incorporating a PROPELLER BRAKE and using the core of the engine as an APU when operating out of remote airfields.This is why on a free turbine airplane, you will see a GAS GENERATOR SPEED gauge (Ng) and a Propeller RPM gauge (Np, PROP RPM).In a geared, or direct drive engine (TPE331). The shaft runs through the entire engine to the reduction gearbox for the propeller. The propeller is physically connected to the engine, and in the TPE331s case, the propeller GOVERNS the engine RPM (with back-ups of course). The condition levers place the engine into GOVERNING range, and once 100% RPM is reached, the engine will remain there through pitch changes in the propeller.This is why you only see the one RPM gauge for each engine on the J41, because its all connected.The main advantages of this geared set up are:-A substantially smaller engine for the same or more horsepower-Instant response to power lever inputs (due to no spool-up or spool-down time)-Greater fuel efficiency (physically connected engine, no wasted energy in the fluid coupling)Hope this clears everything up. :)

Hi Kevin,We have spent alot of time making sure the J41 sounds are very close to the original - I think you are getting confused with the levers in the cockpit! The left levers are called the "throttles" and these control the pitch angle of the propeller blades - moving them forward causes the airflow sounds to vary. The right levers are the "condition levers" - these control the RPM of the engines, pushing these forward makes the sound you are expecting. Have a little play of the combinations and compare them to youtube videos and see if its any better?!

I've been in the (real) aviation business over 30 years and I know the difference between power levers (not throttles) and condition levers. Hell, I even read the manual which came with the sim. ;)On the video I saw there was a clear change in sound when the power levers were advanced (condition levers already at 100%). It's a small change compared to the run up to 100%, but still evident. I accept it's only a youtube video, but as the engine is producing much more power at this point it makes sense that it is producing more noise too.With the CL set at 100%, when you increase the PL the blade pitch must increase to maintain RPM at 100%. This increase in blade pitch will change the engine sound. Maybe not much, but noticeable.EDIT:On reviewing those videos again, I accept the sound change as PL's are advanced is small. Frequency is the same, there's just a little more volume.Kevin

Apologies Kevin for going the wrong way - we have tried to make the engines sound as you describe - for example, on full power condition lever setting the RPM is around 97% and when you push the throttles forward you acheive 100% RPM - there should be a difference in volume between these RPM values but within the constraints of FSX it is difficult to boost the volume considerably between 97% and 100% RPM, but there is a difference in volume between these values.