I am using Big Sur Mac iOS and Audacity 2.4.2.
I am trying to record mixes off of Rekordbox on my Pioneer DDJ- SB2 through a USB connected to my computer and controller. I cannot get the monitoring to recognize the music coming through from Rekordbox. I have downloaded soundflower and selected the appropriate setting as I found on your website without any level changes on the monitoring portion of the app. Any help would be great.
So I am not sure exactly what it is you are trying to do with Audacity…
Are you able to do anything with Rekordbox ?
Are you able to do anything with the Pioneer ?
What specifically do you mean by “the monitoring” 
I am trying to record my DJ mixes for practice through Audacity. I can’t record streaming tunes and have to buy them to be able to record on Rekordbox. I am sure for copyright things. I am just wanting to practice on my set and not make money. The process works already without Audacity (I.e. Rokordox and my Pioneer DDJ- SB2). I downloaded Sunflower as I heard that would help but I may not have the right configuration for input/ output or maybe a driver that I need. I have looked at a few posts on the forum and manual but none has worked. Monitoring, I mean I can’t get the sound from Rekordbox to be noticed by Audacity on the monitoring portion of the set-up. I hope this helps.
Unfortunately, I am not a MAC person, and I really would need more specific detail and messages of exactly what you have tried and what has failed. Hopefully someone more knowledgeable will step in with some advice or suggestions. 
In the meantime, you may find some answers or find some ideas or inspiration at some of these web sites which are related to your specific issues:
https://www.reddit.com/r/DJs/comments/az2x5d/problems_connecting_pioneer_ddjsb2_to_macbook_pro/
https://www.reddit.com/r/DJs/comments/9lzzmm/is_rekordbox_free_with_ddj_sb2/
I hope this helps.
Ok I am going to post attachments of different pics of the audio set-ups that I am using. It starts with my Apple audio, Audacity audio, then Rekordbox audio setup.
Then I have my Mac USB connected to my DJ controller and the RCA outputs go to my speaker.
I have tried a bunch of different configs for them all using Sunflower, Rekordbox, etc. as input and output. Not sure what would work.
Thanks for looking.
Joe
Or should I just get this to record audio from Rekordbox, through my computer, to Audacity. I am just wanting to mix and be able to record them on Audacity and play them back. This interface seems to me that the RCA outputs just link the controller to the computer via the USB which I am already connected to the computer through the controllers own USB connector. Just so you know.
Thanks all,
This page on the Audacity wiki has instructions for setting up Soundflower in order to record system audio in Audacity.
You may also want to check out Blackhole, which is known to work with macOS 10.15. They have instructions on their Github page for using Blackhole with Audacity.
– Bill
Ok so I tried both options you listed and the Blackhole and Soundflower were similar in their setup. Now I can get sound from say Youtube off of my internet and originating from my laptop but when I try to have sound come from my controller there is no audio. Not sure what to do. I tried different configs for everything and nothing comes out from Rekordbox through my controller back to the computer to be recorded in Audacity. Will the module I sent a picture of work for my situation if the applications won’t. Basically working externally instead of internally.
So I remember recording via a 1/8" male to 1/8" male cable from the headphone output to the line in circuit. Today, with no line-input ports, you really need to jam a USB box somewhere in the works. Yes, to me it seems the Behringer box could solve the problem. Do you have one? Let’s wait to hear from Bill before buying one…
Will do. What exactly does it do? Is it the same thing as my DJ controller plugged into my computer with a USB? Just curious.
When playing audio with the rekordbox, you can hear it through your computer speakers, right?
What exactly does the rekordbox do? What they say on the website is not very helpful to me. Does it play and mix audio from external sources (CD players, USB sticks, etc) or does it control the mixing of audio that is already on your computer, or does is control the mixing of audio that is “in the cloud”?
Does the rekordbox send audio to the Mac over USB? Why are you trying to use Soundflower or Blackhole? It seems you have (one of) them doing what they’re meant to do which is allow you to record the computer’s sound with Audacity. So if the computer is playing the sound from the recordbox then Soundflower or Blackhole should “hear” it and send it to Audacity.
What is the “rekordbox Aggregate Device” listed in the dropdown menu for “Recording Device” in your screenshot? What happens if you select it?
The USB audio interface won’t do you any good if the rekordbox is already sending audio to the computer over USB.
Sorry, but I’m totally confused. I’ve never seen or heard of the rekordbox before and I’m trying to understand what it does.
– Bill
Yes I can hear Rekordbox on the speakers of my Mac no problem.
Before I go into answering your questions, I do want to say that Rekordbox allows recording but not on streaming music that I get from the internet. I have a subscription to streaming sites to use before I buy them. If I buy the tracks I assume I could record it fine on Rekordbox.
Rekordbox is a program that houses my music tracks and allows me to mix, filter sounds, and DJ those tracks. Much like Serato or Tracktor which are DJ programs as well. It can utilize DJ controllers, mixers, turntables, CDJs to all do the same. Its a medium sort of speak for Djing.
I do plug it into my computer with a USB. I tried to use Sunflower and Blackhole from advice here on the forum chat we are on and from info I found on Audacity itself. I think it is to allow the recording of music on Audacity without an external device. I think.
The aggregate device has been on there and I’m not sure what it is, but yes I have tried using it to select to enable the recording but it does not work. I have tried multiple ways and selections on my Mac audio, Audacity audio, and Rekordbox audio to see which configuration would work and none that I have tried work. Maybe I haven’t found the right combo of devices but not sure.
Good point on the USB interface as I already have the controller connected to my computer by a USB. I thought that may be the case. The only thing I thought is that connecting the RCA output connectors that I usually put the line into the input of my speaker to hear aside from the computer for better sound. I thought that connecting that to the input of the interface and then using that USB it might work but the USB from the controller to my computer should be doing the same. Right?
I appreciate your thoughts and help with this.
OK, just to make sure I understand.
Rekordbox is a program. It allows you to mix the music you have on your computer.
The thing that is connected via USB is a controller - it is not Rekordbox, but can control Reckordbox. But the thing connected via USB has audio outputs (on RCAs) that you can connect to external speakers for better sound.
You can hear what your are mixing with Rekordbox on your built-in Mac speakers.
You say you have one of Soundflower or Blackhole working and can record the audio you hear on your computer when playing a Youtube video. If you can do that you should be able to record what Rekordbox is playing.
Here’s an experiment. Get something playing on Youtube. Make sure you can record the audio (of the Youtube video that is playing) in Audacity using Soundflower or Blackhole. While the video is playing, start playing something in Rekordbox. Can you hear it (along with the Youtube audio) on the Mac speakers? If so, does Audacity record both the Youtube audio and the Rekordbox audio?
– Bill
Ok so the experiment goes like this I can record the YouTube audio by itself without Rekordbox playing but when I try to play both it only records the YouTube audio but I can hear them both playing over the speakers. So weird. I was unsure if Rekordbox played through my computer speakers as I said but found out that they do. In Audacity I am using the Built In Audio setting for playback and Soundflower for recording. I feel like I am almost there but there is some configuration that is wrong so it won’t do it. Ha ha. So weird.
So weird.
No kidding!
The result of the experiment suggests that Rekordbox is doing something strange with its audio output that prevents it being recorded. I have never heard of such a thing and I can’t imagine how they’ve done that.
Let’s make sure you can actually record two audio streams at once. Start a Youtube video playing then start something playing in iTunes/Music. Record the computer audio as before. What do you get?
– Bill
Great idea!! So it does record Itunes on Audacity with and without YouTube playing. Now what?
It must be a miracle. Now Rekordbox works. Just you saying it made it work. I didn’t change anything. Maybe turning it off and on realigned everything for some reason. Cause now it works. I’m beside myself. Thanks for speaking connection into my set-up. Ha ha. So for those with the same problem I set it all up according to this link:
and tried to record YouTube and my controller with Rekordbox at first in which they both played but I could only record YouTube. Then I tried to record YouTube and Itunes and it worked. I don’t know how, but I turned off my computer then on and it worked. Magic. Thanks Bill and whoever else helped me on this thread.
It may have to do with the particular order of connection of my controller and turning on Audacity, Rekordbox, and Mac restarting. Something related to that. Not sure.
Glad it is working for you! But …
I hate these “magic” solutions. 
If you ever figure out exactly how you made it work please post here so others may benefit from your experience.
– Bill
Will do. I need to mess around to see how to get it back to regular sound without using Audacity. It’s odd. When I find out how it all works I’ll post it here.