Engine Prime and library management is so frustrating

Hey, all. I am not computer or tech illiterate. …just want to start with that.

After a call to tech support I figured out it was a simple drag-and-drop from my external to the prime software. this creates the “engine prime target” on the external drive. okay, cool.

Now I have two files on my hard drive. One houses all the music. The other houses the Engine Prime folder.

For some reason, unbeknownst to me, after analyzing all of the files, Engine Prime left most of them in their original folder and put an odd amount in the ‘music’ sub-folder in the engine prime folder.

i don’t want a random 20 albums in there with ALL of the other music in the music folder, so I moved them into the general population with the rest of the music, re-analyzed the albums, and now they are unable to be loaded.

What the heck is going on with this software?

What in the world do I need to do to get my files back in a playable condition?

This is all making it seem like vinyl might worth lugging around again.


I can’t tell from the above what you’ve done, but Engine Prime doesn’t write to any music files, except for tags, if you choose to change tags one by one.

You are using the software wrong.

Forget the usb drive you want to use with the decks for a moment, you should have your music stored on your pc not the usb drive, then you import the folder to prime by dragging the folder in to prime or via the menu, once this is done and analysed etc plug your blank usb drive in and use the prime software to pack/export your collection to the drive which you then use in the decks.

Think of it this way, your master collection lives on your PC, you then export a copy from prime to a usb to use on the decks, if you have both on the same drive you effectively end up with 2 of everything as you describe, that’s not the right way to use it.

Check the Denon youtube channel they have tutorials for this

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my master collection doesn’t live in my computer. for various reasons, i don’t want all of that memory taken up on the computer itself. my collection lives in the hard drive. …with backups living in other external drives.

if i drag and drop the files directly from my external onto the ‘collection’ pane in Prime it leaves the music in place and analyzed. if i drag and drop from within prime to the external it doesn’t add the music to the music folder but instead adds it to the ‘music’ folder within the Engine Prime folder that it created for itself. this leaves music in two locations instead of one solid collection.

Hi @PlumWrinkles

It is certainly possible to use your music stored on an external drive together with engine Prime. Files do not have to be locally on your PC or Mac. I also use it this way. It will be a lot of reading but I will try to clarify things for you

First of all, we must distinguish between the music files themselves and the engine database.

Your music files are already stored somewhere, In your case (and in my case) not on your local hard drive but on an external drive.

The Engine Prime folder (automatically created by Engine Prime) contains files from the database itself and no music by default. This database includes among others your crates, your playlists and the metadata for the players’ search function. In addition, the waveform, BPM and Key are stored for every track that has been analyzed and the set cue’s, loops and beatgrids.

If you would compare the Engine Prime database with a hard drive, then Collection is your root folder (top crate) and crates and playlists are your subfolders. An important difference is that these are virtual directories. The files do not have to be in these folders. Crates are used to organize music in custom categories. Playlists are also do this, but they have a fixed play order by number.

In the current way that Engine Prime works, all databases are merged into a large displayed database. I would recommend turning on the Drive column for columns (Right click on the row with Art/TItle/Artist/Album etc and choose Drive in the track list). With the drive column you can clearly see on which disk you are working. Off cource make sure that the drive is connected when you want to work on your external collection.

You can add or import music to the collection in various ways. When you add or import, the music file itself is not placed in the collection, but a reference in the database to the original file.

  • You can drag and drop files directly to the collection via Explorer or Finder. Alternatively you can click on Files Tab (internal File System Browser) in Engine PRIME and drag it from here to the collection. This is possible with separate files or with several at the same time.
  • You can drag and drop folders directly to the collection via Explorer or Finder. All files within the folder will be added to the collection. If you drag multiple folders at once only the files in all that folders are added into collection. If you drag and drop a single folder (one by one) the files will be added to the collection and a crate with the folder name will be created automatically.
  • You can import iTunes/Traktor/Serato databases

When files are added in the collection a reference to the file is written in the database. So if you delete or move this file from it’s original location Engine Prime cannot find and use the file anymore. You will have to add the file again (currently there is no relocate function). Best way to use is to leave the file on it’s original folder on your drive and to organize further with crates. You can use a file multiple times in different crates. This makes it easier to move to another crate or remove from a crate, without the file no longer being lost from the collection. You also have the original file only once on your disk and no copies.

I think it’s best here to remove the files that are unavailable from the collection and add them again when you have them stored where you want them to be.

Above is not correct info. If you see doubles than that’s mostly because their on different drives.

The Main Collection is a complete list of all connected media, both remote and local. This allows for all of your songs on either connected hard drives or internal storage to be used interchangeably, making it easy to find your track regardless of where the file is stored.

Because of this, duplicate entries may appear in the main collection if a song is located in both the main collection and a removable drive. Songs are not physically duplicated on the drive, the main collection is simply reporting the song in multiple databases. Removable drives can still be moved from one computer to another and have their crate structures retained, and any song in the main collection can be dragged to the Engine player for playback and editing at any time.

Denon says they are working on a way to improve this. We realize that this is a departure from more traditional workflows and are working on an option to separate collection drives with remote drives in a more clear manner.

Correct, as explained above

I think you move files from collection to target USB from the Devices tab, am I correct? What are you trying to do when you move from prime to external drive?


Thanks @addie for your writeup. It’s in accordance to my recent feature request for EP: (Clear and complete instructions on the inner workings of EP).


Two “please like my suggestion” spams already. No more on the way, I hope. :grimacing:

If an idea has got legs, it’ll get there without begging / spamming

Not really begging or spamming, but letting people with similar problems know that a request exists. Anyway, thank you brother 1st warden!

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Or sister, in this case

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I stand corrected. Best regards, then, sis.

omg. thank you for this super detailed reply!

my main mix up happened as a result of a faulty external SSD which has since been replaced with a Glyph drive from sweetwater.

i moved all of my music to the external and deleted it from my computer. (this was the initial brand new drive that failed… not the current Glyph drive which has otherwise been excellent)

this was the first real hiccup with Prime. i no longer had any playable files, as I’d moved them all elsewhere. oops. shouldn’t have done that.

i got the new drive, re-download all of my bandcamp purchases… (like 600 albums!) and moved some other music over from other externals.

great. now i’ve got all the music I want in one place!

so, after the call with tech support, i realize all i have to do is drag-and-drop the entire collection from the external over to the main ‘collection’ tab in Prime, thus creating the Prime Target Device folder. everything is peachy.

then I found another drive that i had been performing with for a few months and wanted to drag those files to the new external.

so, both drives are now connected to the computer and to Prime. Within Prime, I, for whatever reason, decided to drag them from the one USB to the other, as opposed dragging outside of Prime from the old into the new drive.

this is when Prime didn’t put the music into my main external collection that I’d started with. it put its tags into the ‘music’ subfolder within the Prime Target folder. so, now I’m not even sure where those files actually live. I’ll see when I get back to my deck if they are playable from the new drive.

so, basically now if I want to add music to my main performance drive, I have to add it by dragging from drive to drive, skipping Prime until it’s time to then drag them one last time into the Prime ‘collection.’

this is the only way I can think to keep it all organized, but I still don’t know why so many tracks are now red in Prime. right-clicking to ‘remove’ the red tracks from the hard drive is grayed out and not an option.

i’m stuck with a bunch of red unplayable tracks at the moment.

i just want to be organized and know what’s going on. Prime seems to currently be out-smarting me, but I feel like your long reply shines much needed light on the topic, and for that I am grateful!

sorry to jump on this thread but is kind of relevant … so — the bit i’m still not sure about is: i have imported / analysed / put in a crate then packed to prime 4 internal ssd. are these tracks now 2 completely different entities? eg: if i move one of the tracks to a different crate then plug in the prime 4 again will this change be reflected or do i have to do it twice? — i know you can sync changes on the device back to the computer (cue points and what have you)

you can sync your “mobile” library back to the Prime library. there’s a button in the program for that.

this thread is still live. i’m going to post a video demonstrating the oddities i’ve mentioned above

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pity it’s not both ways tho …

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I have a question about itunes playlist import.

I’ve got an itunes library with lots of playlists. all tracks were imported and analyzed in the main collection.

that collection was then dropped onto usb and is usable on p4.

in ep the itunes playlists show on the itunes tab but have to be imported separately, before you can then export them to usb.

my question is, if the actual files are already on the usb, why does it take so long to copy the playlists? it seems like it takes the same amount of time as if you were copying the actual tracks over.

Not sure if this answers your question, but I find a huge read/write time difference between USB 2.0 and USB 3.0. I use Serato for music management. As a test, I dropped identical files and crate information on to both a USB 2.0 and USB 3.0. Taking both USB’s to Engine Prime, there was a significant time difference in EP making the USB’s ready to play. I recommend using a quality USB 3.0 drive for your music.

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Es könnte so einfach sein …

Einfach Ordner mit MP3´s auf den Stick oder Platte kopieren … ganz normal mit Explorer oder Finder … geht sogar richtig schnell …

Dann Engine Prime Starten … Auf nen Sync drücken

Engine schaut nach was für Ordner enthalten sind, setzt die BPM & Beatgrids … schreibt alles in eine Datenbank ohne MP3´s in eigene Ordner zu verschieben. Und übernimmt die Ordnerstruktur als Crates. Und wenn PLS oder M3U Dateien vorhanden sind, macht er noch Playlisten draus …

Aber warum einfach … geht doch auch umständlich …



Engine Prime is fundamentally flawed in a very early stage of its design.

I think it was design for the DJ who denon wanted to target as ambassadors for the brand, rather than the real mass users.

The idea of someone having 20,000 songs at home, but only exporting 50 to 100 to take out with them for their perfectly rehearsed set that night probably works perfectly well for Laidback Luke, tiesto (not heard about him via denon recent), Oliver Helden (not heard about him via denon recent), Steve aiko (not heard about him via denon recent), or Paul oakenfold (not heard about him via denon since the English stone henge gig 18 month. All these people probably choose their export tracks to little usb stick and leave their big collection at home.

Engine Prime seems written to them - perfect

Lots here on the forum seem to be the type of DJ who have 75000 tracks and need to take all 75000 tracks to EVERY where, EVERY night, EVERY time. For us the idea of a main collection at home and only exporting 1% of that collection to usb stick is completely alien and unworkable.

I’m just exporting my entire collection to two identical usb drives every single week. This means deleting everything off from both usb drives first, then exporting all collection, all crates, all playlists - every week just because we have bought 50 new music track.

Engine Prime is not made for majority DJs - it’s been written for the elite poster boys DJs

Throw it to the bin, write it New, call the new one Engine Prime to, if you feel for consistency but don’t make us export entire collections, crates and playlists before every event , just to do our job. We are not laidback luke, we are the 999,999,999 DJs who are other DJs


Enhancements are on the way. Yes it takes time and most of us don’t have that.

About the fact you would need to delete the entire drive: You could do it with a file manager like Total Commander to compare and sync changed files.

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I tried that with robo sync or sync toy (both same I think) and others and I had issues with “file not found” messages from music tracks.

I think this was where Engine Prime thought a track was in one folder but sync tool had put file into different folder