I found the native support for this is lacking after many attempts and forum posts. For example, if you choose to filter Duplicates of Album, it doesn't work to show you duplicate albums, you have to further filter down to Name or Duration.
That is one way to find true duplicates. More likely, you will have many duplicates with small naming variation, probably in Album field.
There are soooo many posts on this, I don't get your comment. ?
1) you must first define what IS a duplicate for you
.. short of "sonic fingerprinting" this is going to be found only through metadata. The stock smartlist JRiver provides might not be sufficient, but it wil get you started. The screenshot indicates two albums by Miles Davis ... these would
not be a duplicate for me as one is an SACD version the other a normal flac version. But it might be considered a duplicate for you -- one has to decide what is and what is not.
As HiFi tubes said variations in certain fields will be considered non-duplicates. Capitalization (usually shouldn't matter) and cleaning up leading and trailing spaces can be done via Library tools if needed. Otherwise define duplicates first ... Same Album Name and Album Artist is enough? or is it track based using same Name, Artist, and Album? or do you add file format, track duration, track number etc. to further find a true duplicate. You choose or you have more than one and vary the search parameters.
2) Set up an admin view or smartlist (see the wiki if you don't know how)
what I look for as more or less true duplicates is that The Album, Track Number, Album Artist and Track Name are the same. Here is my filter for this that you can import (or modify) by copy/paste if you want using the Import button (Customize View/set Rules for file display. Note this is for non-classical recordings only. My classical collection is tagged differently. I also use the Grouping field which you probably don't so is superfluous.
[Media Type]=[Audio] -[Groupings]=[Classical] ~dup=[Album],[Album Artist],[Name],[Track #] ~sort=[Album Artist],[Album],[Disc #],[Track #]
you might prefer using Artist rather than Album Artist.
Bear in mind that if the artist or album artist fields are often different, they are still not going to be considered duplicates depending on your filter (eg; Miles Davis and Miles Davis Quintet with the same album name - is really a duplicate for you) -- if that is where a lot of dupes are happening you could use just track name+album name+ maybe track number to find potential duplicate for example. Track number are often indications of different versions which you may or may not want to keep, to illustrate what I mean.