Need help with something regarding an MP3

[cyrano]

This isn't as simple as it seems...

If I understand correctly, you have the sound of a bus going 55 kph and you want it to sound like it's doing 60 kph?

I had to produce a similar effect years ago. There is some Russian specialised hardware/software combo that can do this. It's aimed at model builders and film crews and comes with samples of different engines, from a V8 to a steam train. It's not exactly cheap. It has a control input for speed and a built-in DSP that handles the speeding up and down sounds from an array of samples. And if you want, you can record your own samples, but this needs to be done in a sound-wise clean environment and is quite time consuming.

We didn't use it in the end, for budget and time constraint reasons. I just recorded all the sequences of a real engine we needed. A lot of recording, but easy enough. The actors just had to play along the soundtrack.

I still see no way to do this realistically in a DAW, whatever effect used. Especially since your sample is drowning in some sort of modulation noise. Digital transmission? FSK modulation?

[MT3269]

The annoying [bubbly] background-noise is compression-artifacts : they are caused by using a low bit-rate , (nothing to do with AGC).

A free plugin called DtBlkFx can be used to reduce the bubbly compression artifacts somewhat ...

''agcnoise'' after DtBlkFx plugin_.flac

DtBlkFx plugin showing the 'Motor-Cycle' settings used.png

Motor-Cycle.xml

Thanks for the link, but are there any tutorials that show one how to use this function in order to get a desired result? The manual doesn't pinpoint roughly what I need to do..

If I understand correctly, you have the sound of a bus going 55 kph and you want it to sound like it's doing 60 kph?

I had to produce a similar effect years ago. There is some Russian specialised hardware/software combo that can do this. It's aimed at model builders and film crews and comes with samples of different engines, from a V8 to a steam train. It's not exactly cheap. It has a control input for speed and a built-in DSP that handles the speeding up and down sounds from an array of samples. And if you want, you can record your own samples, but this needs to be done in a sound-wise clean environment and is quite time consuming.

With this particular rogue vehicle, it's very difficult to replicate the revs at 60kph using input of it sitting on 55kph. I have tried everything, including using the increase function to lower the speed and increasing the pitch, whatever I could think of. The file has an issue due to the sensitivity of the mics on the device. It's a very high pitch sound which caused clipping. It would still do it today even if I used the settings I use now (normal bitrate, standard volume, lo cut, AGC limit2, 4 channel mode). However, the amount of distortion would be less. Unfortunately, the vehicle has been interfered with (as in had some maintenance) and hence this unique...sound can no longer be recorded.

Is there a demo version or something of this software you mentioned which one can squeeze in a few minutes of use to get an example of it's supposed capability?

[Trebor]

... but are there any tutorials that show one how to use this function in order to get a desired result? ...

I included an .xml file which has the settings I used in DTblkFx , which you can load into DTblkFx as a preset ,
or just manually adjust the settings to match this image ...

[cyrano]

Is there a demo version or something of this software you mentioned which one can squeeze in a few minutes of use to get an example of it's supposed capability?

I'm afraid there isn't. You have to procure the hardware with the software. And I can't even find a link to it. Russian sites aren't very well indexed by Google and even Russian search engines can't seem to find it.

I've never been able to produce this kind of effect, but maybe one of the other forum regulars is smarter...