Reaper - How to disable stretch when changing BPM ?

Hey I need a little hand please... I selected a portion of an MP3 and found out it was 84 BPM (I love that Reaper can do that) but then I want to set Reaper to 84 BPM because it's 120 BPOM by default and it stretches the tune...

I don't want to stretch it, it'll be perfectly aligned at 84 if intact... now I know that I can just re-import the tune at 84 BPM but I'm sure there's an option to disable.
Wait, what?

How do? ¯\(°_o)/¯
 
Select something precise like 4 bars, well cut on the wave forms, and check at the bottom of Reaper, on the right. There are some time/code selection things, just put your mouse over it (don't click). :loco:

RedDog, unfortunatly, it does not work ;(

That sounds interesting.. I'll have to try that out^^

What RedDog said should work.. Alternatively you could try to set the timebase of the whole project to time:
Alt+Enter -> Timebase for items/envelopes/markers: -> Time
 
If you set the timebase of the item to beats (position) only, I think it should always map to the position you have it in terms of what bar it starts on, but it should be unaffected by any change to project or section BPM. That way it's unaffected by time and tempo changes outside of that item. I might be totally sodding wrong though.
 
Dude, in project properties (alt+enter), select "project timebase" to "time" instead of "beats" as it is by default.

It can also be done individually by tracks, by right clicking on the track and changing the "set track timebase to" option to "project default" or a specific one for that. Simple rule is, "beats" for midi tracks, "time" for audio tracks and all should work fine
 
Select something precise like 4 bars, well cut on the wave forms, and check at the bottom of Reaper, on the right. There are some time/code selection things, just put your mouse over it (don't click). :loco:

RedDog, unfortunatly, it does not work ;(

I don't understand. This isn't working for me...unless I'm doing something wrong....
 
Dude, in project properties (alt+enter), select "project timebase" to "time" instead of "beats" as it is by default.

It can also be done individually by tracks, by right clicking on the track and changing the "set track timebase to" option to "project default" or a specific one for that. Simple rule is, "beats" for midi tracks, "time" for audio tracks and all should work fine

This, whenever you have a sync problem with stretching/tempo markers, check the timebase settings and play with them.
 
I've having a serious issue with this right now. A band gave me some drums (midi) with the tempos embedded, but the tempos are doubled in their version.

So, the start tempo is 280, but I want to halve it to 140 so I can embed the "proper" click source. Everything I've been trying stretches the midi out. I can manually shrink the midi down to "Playrate 2.000" once I've changed the Time Sig/Tempo Markers, but then it creates a weird spot in the song where the "1" beat doesn't fall on the "1" grid line, and I can simply move the Tempo Marker to it's correct spot, but the grid doesn't change and it throws my click off.

A slight workaround is to set the temp to 4/2 and it provides the proper click speed. I adjusted Timebase settings and all that, and still, every time I change a tempo marker, it stretches/shrinks the MIDI info. I guess I can get by with this little workaround, but it's still frustrating.