Yes. To elaborate further on answers above... Since I specifically use Reason 5 for the betterment of most of my recent tracks since November 19, 2017, strangely right before this was posted, I wouldn't just lower the bass... Here's a pretty thick response:
The "Mixer" at the very top... That's the master mixer.
- Do not touch/play with the Volume Control/Track at the far-right of that Mixer, which is the Master Control of the entire track... Regardless of the DAW, even FL Studio, Ableton, you want to keep that Master Track Volume at 100, i.e. at its default.
Those other tracks/volumes are obviously the tracks connected to the devices you are adding, i.e. NNXT, ReDrum, Kong Drums, etc. You get that. I am not going into that whole jive, because it can get heavy, but quickly... To disconnect or reconnect or fiddle with connections to tracks, as the commentator above stated "side-chaining" which in Reason 5 can be handled by hitting "TAB" within Reason 5's MAIN window aka "rack" and it flips the machines/devices over to their back. It is actually pretty dope because it emulates physically messing with wires in a realistic studio setting at home or whatever... So cool. But, yeah. 2 wires, In/Out, Left/Right, Audio In/Out, etc. however each device assigns that specific function, that's where it gets handled automatically when you add a new device-- but reason I'm bringing it up is #1. Just in case you didn't know, #2. to give a more detailed explanation of the Master Mixer and Track Separation, and #3. If, and it is definitely plausible, you decide to make a beat, and within that beat messing with melodies and end up making a new melody suddenly, but are all like, "I gotta save this, log out, create a new one," blah blah. You can just easily Right-Click on a device, even with a recorded track, and open a new Reason app, Ctrl-N for shortcut... Then paste device into its area. THEN, you'll hear NO sound and be like, "W-T-F, mate!" haha. So you TAB, flip the device, and boom. Do that wire thingy. Route the I/O L/R audio 1/4 inch plugs to the first open track... or whichever track on the Master Mixer you'd desire.
OK. So, you got this sound problem. The "meshing" of sounds is like, sounds like it is drowning out, or completely changing? Yes I know. Happens for me a lot. So, you have the Mixer Controls of each Track Device above. Boom. What I do is, this is me... for BASS, SUB, etc. I affix -16dB on the BASS/TREBLE meters of the BASS/SUB track. -16dB is a reasonable area to start and keep mix after mastering. It's acceptable, even if a streaming service or app/program has that "compression" function or YouTube uploading videos of your audio song, etc. it's going to compress it. =16dB is safe. I believe Moby is in the -12 to -9 area of BASS in many songs.
But also, right-click the actual device of the sound you want to change, or both...in this case, a BASS and say, a SYNTH that is being drowned out by BASS. Right-click and in that context menu that pops up, Click Add Effect, instead of instrument. In the Add Effect menu... Boom. There's some sweet Reason Factory-included Mastering effects, Dynamic effects, etc. I most always append Mastering to it. Check them out. Fiddle around. Also, on that Context menu, BEFORE you even click Add Effect... Avert your eyes to the bottom part of the menu that you have popped up and actually, right there are interesting "Device-specific efx" such as Stereo Shaper, I believe it's called. THAT my friend is like my new best friend. There's also Limiters, 2-4-and-8 band compressions, with or w/o Limiters. There's another awesome device effect called Unison which detunes & "wets" the sound. THIS is also a strange but unique and second best friend as I work in classic Hip Hop, early 90s style genre, LoFi NuJazz "A Tribe Called Quest" Jazz-infused and influenced Hip Hop so yeah... Especially with maybe an Electric Piano...OMG. So beautiful.
That's pretty much the whole of it, or at least, to get you feeling better & more "into" Reason as it's such a beast, bro. Reason 5, IDK about you, but it's obviously cracked and free online and Propellerhead fixed it so that Reason 6 to 10 (current version) are un-crackable. However, Reason 5 is DOPE. Just lacks VST Support/Hosting and Audio Input/Recording, i.e. from your interface (i.e. Microphone, Instruments). There's a program they have or had called Record 1.5 supposedly that allows this, but can't find it and honestly... I am buying 10 when I get the $ up. It's $430, was $500 originally. It's $400 in many places, online I believe it's even $350s or around there under random coupon events, or price slash deals, etc. You just gotta pay attention.
Reason 5 is truly without limit once you get over the No-VSTs/No-Audio Recording Options... Yes, those are IMPORTANT. But, take Tribe Quest... In the 2011 Docu, "Beats, Rhymes, & Life" Q-Tip spoke of, I paraphrase loosely, "When you were a kid, most people starting out in Hip Hop, you're working with what you got". So until I can buy it, and I most definitely will, I'm making dope music with both Reason 5, FL Studio 12, oh yes, and Ableton live 9 Lite though haven't mastered that anytime soon--and I'm talking just the very basics. It's a whole animal in and of itself!
So, I hope while this was elongated and deeply verbose, haha, it's to the point and necessary man. Any help I can give. Plus, I want to score some points. The guy above is right though, at the end of the day, you really are leveling out the instruments/devices tracks with one another... For that is the most raw & concrete, stripped definition of "mixing". You are mixing sounds together in a smooth and easy-listening (depending on your taste/genre/project...even if it's just audio voice or for a movie, speech, etc. or a commercial). Then Mastering, well, that's taking that sweet mix (and many times, people aren't mixing at the top...in the first part of the cut/production... Many mix/master at the end. But that is mastering... Mastering is technically, in a broken down easy definition, making "lasting mixing fixes, cleanups, etc." and adding fades, adding mastering and dynamic effects, compression, who knows...all of that. Prepping it up for a final "mixdown".
Good luck bro!