One of the best-kept secrets of mixing records is referred to as the “black background” effect. Well, it’s not a secret insofar as you’ve heard it on classic records for decades. How to achieve it is quite another story. The concept is as follows: If you think in terms of instruments and voices as colors projected on a black screen; the contrast makes the colors appear that much more vivid and defined while maintaining a cohesive overall image. In DAW mixing, the exceptional ability of digital sampling to capture bass, even in the inaudible range, turns your background gray, clouding your mix.

Why does this happen?

Bass frequencies act omnidirectionally, whether they occur as waveforms in reality space, or as “1s” and “0s” in the digital realm. That means they permeate the stereo field. When you consider that left and right are all we really have in stereo and that the center image is an illusion, an instrument, with a preponderance of lows, even though inaudible, can unbalance a mix in a way that’s difficult to audibly pinpoint (an effect more noticeable in headphones, subconsciously drawing your attention). Keep in mind that instruments overlapping in the low- and low-mid frequency range will combine and reinforce in uneven and unpredictable ways. The result is a mix that’s smeared and muddy in the lower frequencies.

Some mixers and mastering engineers suggest using a high-pass filter on every track as a starting point, but that runs the risk of thinning out the mix, taxing CPU resources better used for creative ends, and also eating up headroom—so no net gain there. OR, you could simply put the Boz Digital Labs Mongoose on your 2-bus and you’re moments away from achieving this arcane skill of A-list mixers and mastering engineers.

Mongoose works its magic by summing low frequencies to mono so that equal levels occur left and right, which focuses them in the center image, leaving plenty of room on the sides for instruments.

Mongoose—Just the Facts:

  • Sums low-frequencies to mono with adjustable crossover
  • Very low CPU impact
  • Focus and tighten low end while ensuring mix translation
  • Create contrast with high-frequency widening
  • Sculpt the width and depth of a mix
  • No phase issues when summing to mono


Mongoose has a simple, no-frills interface, focusing all of your CPU resources on sound and function. The slider across the top sets the crossover point, below which, everything is summed to mono with either a 6dB or 12dB slope (your choice). Once set, its three sections, Low, High, and Master, give you control over gain and width below the crossover, above the crossover, which is the side information, and master mix, gain, and overall bypass. The Low and High sections also have a solo feature so you can hear exactly what you’re doing in each region.

While it would be perfectly legal to refer to it as a mid-side processor, what sets Mongoose apart from any other M-S device is how easy it makes it to achieve universal mix translation and mastering-quality results via a simple, but very powerful set of controls. Mongoose enables you to sculpt the width, depth, and contrast of your mix in myriad ways—and it does it without the phase cancellation that occurs in other spatial processors. Make a mix as narrow or wide as you please, sum it mono in your DAW or mixer, and your instrument balances remain intact.

Additionally, if you like to move in and out of the stereo field, for example, going wide to add excitement to a chorus, you can automate the width of both the Low and High sections.

Take on Mongoose

Keep in mind that our job as mixers is essentially the same as that of a magician: to create a satisfying illusion in the mind of the audience. So while left and right is all we have in stereo, mono bass summing focuses the center image while creating the illusion of greater space in the stereo field, which in turn simplifies the mixing process. Mongoose makes it easy to achieve a focused and punchy center image with as much width on the sides as you like.

You’ll have your Aha!! moment when you put Mongoose on your stereo mix, set the crossover at around 180Hz, narrow the low-frequency gain to 50%, widen the High section’s width to 120% and boost a little bit. Use the bypass for an A/B comparison.It’s like having a button that switches from demo to master.

Reviews (19)

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19 reviews for Mongoose

  1. Rich

    I am already using Mongoose in my projects!! Thanks for this simple but amazing tool. I even reopened an album that was “completed” and added mono (and now Mongoose) as-is onto the master buss…Wow, the mix got cleaner, more focused. With very little tweaking per song, I decided to submit new masters to my Mastering Engineer. THANKS for this plugin.

  2. Dan

    The description says that this plug is effective right out of the box. The description is spot on! I have used this on the master bus of 3 mixes thus far. The default setting made the mix punchier and clearer right off the bat.
    Subtle is boring is Boz Digital Lab’s motto. The width function is this personified. Moving my latest mix from a static 1.00 to 1.06 made a noticeable (and very nice!) difference. It is a staple to master bus during a mix from now!

  3. danzbad

    I agree dan just bought this myself and I love the wdith function you can really bring out the stereo ina track and it really tightens up th ebass and gives a nice clean punchy balanced mix great job boz I will enjoy this plug for years to come.

  4. Mike L

    Wow, I’m impressed on how much this plug-in really cleans up the mix and tightens up the bass. I’ve used stereo width tools and M/S processing before but this plug-in really does something to the mix that I wasn’t expecting, in a very good way. The stereo width is amazing and the clarity of the instruments are very noticeable. I just tried it on 3 of my mixes and with very little effort it made a significant imprvoement This plug-in will be on everyone of my mixes going forward. Keep up the great work Boz!

  5. Stefano Sansano

    This tool!…. THIS TOOL!… crazy, just wow-tastic!

    I….there is….you can….wow, wow wow – just wow.

    Monogoose is the only plugin loaded with my Ableton Live project. I strongly recommend to invest the 25$ for this tool!

    Big respect to the BOZ-Bros for this!


  6. lawn_street

    Very useful tool, great value for the price.

  7. thekraken

    I really can’t imagine not having this on the mixbus now. Probably the best $25 you could spend to really breathe life into your mixes. Tightens up the low end incredibly well. You can blend it in just a little to open things up, make the Kick and Bass lock in the middle and give your instruments some air, or you can really open it up wide and give every sound the whole countryside to roam in! Works well on drum sub mix or stereo pads, keys etc too. Used it on a brass track and vocals to good effect. Been using it on guitar bus as well to either beef up the bottom end, or tame some of the mud. Can’t praise this thing enough. There isn’t any other plug in that can do all this so easily and so effectively for such a small price. Love it!

  8. robbieb

    its amazing i only bought it bacause i had to 2 freebys 😉 only joking lol…then one day i sent boz an email and her replied and i thought great customer service..then somone online said that this plugin was great on the 2bus for getting a tighter bottom end..your right it does.. i dunno how it works but it will be on every mix from today ! buy buy buy.. RB

  9. ncalonne

    Buy it right now…

    I was like “ehh, should I buy that?” for months. When I caved on the Imperial delay intro price, I figured hell, I’ll just drop the 25 bucks and throw this in as well.

    Honestly, all I expected was a bit more clarity, but what I got was a huge boost to perceived loudness, clarity, and the whole thing was a million times tighter.

    Forget multing stuff out! Just throw a mongoose on there. Seriously though… blown away.

  10. Michael

    Great and simple plugin, does what it says on the tin with the minimum of effort. I actually had this for about a year or so but never got around to trying it out, how silly! It now lives in my template, will be using it everywhere!

  11. Duane

    Love this one too, and sooooo tempted to keep it a secret… I’ve been A/B-ing and now realize that it is one of those plug-ins that’ll just stay instantiated all the time.


  12. turkaynisanci

    Amazing plugin, cleans all of the mix. No muddiness, huge low end and clarity. Thank you Boz Digital family for this big plugin.
    The price is also unbelievable.

  13. tommymarcinek

    Mongoose is just awesome. There are so many uses for it! I use it on many tracks, especially on some moving stereo synth tracks that definitely need to be stabilized due to their heavy bass content bouncing around all over the place. Mongoose will keep those low frequencies in the center where they belong, then you can eq the sides, widen them…..anything, and then the synth then becomes BIGGER and BETTER!!!!!! On a master bus the whole darn mix just jells….amazing plugin….worth every dime….they should charge more!!!

  14. howseth

    Mongoose always sits on my mix bus before the limiter. Every mix.

  15. ItsMisterVee

    This plugin is absolutely insane. Had it for about an hour and already hear a huge difference in some old mixes. Bass is so much more focussed and tight and the width rotary for the higher frequencies works very well. Both functions together sound great! Something very simple but extremely effective. Price is very fair too! This is my first Boz plugin and i’ll definately be back for more!


    This plugin does exactly what it says. No deception or tricks on the demo video. My mixes really open up and I’m considering reopening some completed mixes to include it. It makes everything better-er!
    The only frustrating part is, Mongoose is so good right out of the box, any tweak I make seems to take away from its beauty 🙂
    Oh yeah, thank you for the free stuff you have made available, it’s appreciated (and turned me into a customer)!

  17. tramortony

    Awesome! very useful. It saved my life. Thank you Boz

  18. IMAWriter

    “Mongoose” is, IMO absolutely essential to the mix bus of ANY track where centered bass location is preferred. I don’t do EDM, but I’d imagine focusing the bass center will open up all the nice left and right synths, percussion, etc. I LOVE Mongoose! highly recommended.

  19. kevinsparks

    Such a simple tool that has made huge improvements in my mixes. Hard panned tracks feel a bit more natural now


See it in Action - Extreme panning with Mongoose

See it in Action - Extreme panning with Mongoose

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