When syncing two BPM’s of different values to the nearest 1/2 speed or full speed which ever is closer. For example playing a song that is 160 bpm and you want to sync it with a song that happens to show up as 75 BPM, the Slower song should sync to the faster song at 80 BPM instead of the full 160 Bpm. That way you won’t have such a drastic pitch shift in the slower track, and the songs will stay synced.
Moin @AGNS ,
it’s probably related math 
. You can set your 75bpm track to 150bpm and you will get the result you want.
I’m pretty sure you can find a lot threads on that topic with more details.
Regards,
Florian
I totally understand your suggestion, im playing a lot of dnb and dubstep. I always turn of sync when halftime tracks is going to mix in to high bpm tracks.
This can probably be a future ai powered solution. But until then, you have to prepare tracks in engine dj desktop where you can change bpm on tracks or just turn of sync when mixing in those tracks 
So basically a Sync option to sync with halve/double speed. It sounds technically easy to build but from a UX point of view. How do you envision this in the real world? how would you operate such a function?
Any reasons for not just doubling or halving the bpm in the grid editor on your device? It takes seconds to do.
Also when analyzing tracks if using low bpm range all tracks will be in halftime. I have never used streaming as my source, but what happens there? If one track is 87 and the other 174 and you want to use sync?
I don’t use streaming services either, can you not edit the beat grid on streaming tracks?
I have no idea. Im to old 
Really sounds like a case of halving/ doubling bpm on the faster /slower track manually or just using the pitch yourself instead of pressing sync. The sync isn’t really that good on Engine anyway.
How so? I have zero problems with sync when I choose to use it. It’s just about making sure your grid and load cue are on point.
Similar to pressing the touchscreen to alter the musical key, the same approach could be used for BPM for the common divide/multiply operations. I don’t think it’s such a common scenario that it needs a dedicated hardware button combination.
Moin, imo the same isssue, but only for a few beats and horribly when you caught, if you had amanded a track with 6/4 beat (120 bpm upspeeded to 240 and reduced back to 120 or vice versa).
To avoid this, I switch off the sync as long as possible, I switch it on at the moment, when opening the faders.
Brgds BeatMaster
I wish Sync worked like it does in VDJ, only engaging when two tracks have BPMs within a certain percentage of each other.
Sometimes I forget to turn off Sync on tracks with huge BPM differences, which makes the incoming track sound way too fast or too slow.
I’d steer clear of that. If I turn a function on, I expect the device to follow those settings consistently. I don’t want any mystery sidewheels popping up unexpectedly.
Its not a mystery. In VDJ is just simple a setting.
@Dj-PowerG apologies, just realizing i’m probably too tired to interact on the forum in a correct manner. On second thought, it may be a nice feature, as a setting.
I have a denon sc live 4 and stream tunes from Apple Music along with a usb stick.
I use Apple Music to listen to tunes on my phone while at work and favourite tunes I like then can stream and mix them back at home without having to do anything different.
I also have this miss match problem!
I have to use the beat grid every time to adjust the cue points and sync them to the correct bar and beat position that’s usually picked up on the off beat! Once I’ve set the grid correctly to the tune I then use the half or double the bpm on the chosen track (I’ll say this is on DECK 1) . Make sure that the tune you are editing (DECK 1) sync buttons are off!!
Once the bar indicators have been set with beat grid (DECK 1) and this tunes sync button is off, I use the pitch shift fader of this tune (DECK 1) and move it up and down to stretch out/in the grid etc.
now straight after doing this, turn on the lock button in the beat grid edit screen THEN, turn off the sync buttons for the OTHER tracks with the already desired bpm (DECK 2)
This should (if I’ve remembered correctly) bring both tunes to have same beat grid and markers but with ability to use the sync again!
One thing to remember is to not move the pitch control fader on DECK 1 from wherever it is has been placed. Otherwise it will just go back to the original problem!
I could have gotten this wrong with the order of sequence of events written. If so I apologise!
This is already a feature in Serato. DNB and Dubstep can have this issue from time to time. If you are writing in Java it would be an IF/THEN command. If the lower BPM track requires a greater than 2x increase in speed to match the Faster BPM Track, Beat Sync to Half the value of the Faster BPM tracks half speed.
[Deck 1 faster BPM] 168 BPM
[Deck 2 Slower BPM] 75 BPM
Instead of speeding up Deck 1 to to the full 168 BPM, Increase BPM to 84 instead 84x2=168. At 84 BPM the beat will still match on beat.
First I agree with all of you Beat sync should be used rarely and sparingly. But for those who do use this feature from time to time this would be a big win. Yes you can correct all this by prepping your playlist, yes you can correct this by simply doubling the slower track before playing, but once you double it it will always show up in your playlist as doubled so what if you are playing a cool down set or a mellow set at first glance you will no longer find this song suitable because you are reading it as a much faster BPM.
First I agree with all of you Beat sync should be used rarely and sparingly. But for those who do use this feature from time to time this would be a big win. Yes you can correct all this by prepping your playlist, yes you can correct this by simply doubling the slower track before playing, but once you double it it will always show up in your playlist as doubled so what if you are playing a cool down set or a mellow set at first glance you will no longer find this song suitable because you are reading it as a much faster BPM.