Bass "Mono-izer" plugins

[MogwaiBoy]

Any update on this? Boz Mongoose is on sale at Audio Deluxe right now and I'm thinking "so is it the best bass mono-izer?"

[mystran]

I just want to post a quick note that using a minimum-phase (or other non-linear-phase) high-pass on the side-channel is how you end up with phase problems in the cross-over region. The possible solutions (and there are only these three really) are to either (1) use linear-phase filtering and suffer the latency and possible pre-ringing or (2) use an all-pass (eg. Linkwitz-Riley) cross-over on both mid/side channels so the phases match (and suffer the all-pass response) or (3) ignore the whole thing and just live with it.

[djscorb]

Using a one pole (6dB per octave) or bessel filter on the sides is a good way to minimise any phase distortion if linear phase isn't your bag

Cheers

Scorb

[mystran]

Using a one pole (6dB per octave) or bessel filter on the sides is a good way to minimise any phase distortion if linear phase isn't your bag

Both of these will cause phase-problems in the cross-over region, although obviously somewhat less than more drastic minimum-phase filters.

[BRBWaffles]

Using a one pole (6dB per octave) or bessel filter on the sides is a good way to minimise any phase distortion if linear phase isn't your bag

Cheers

Scorb

There is also the issue that high passing the sides does not preserve the low end information in the sides. With this method you can kiss the low end of your panned toms goodbye.

[djscorb]

Of course it doesn't, why would you expect it to? I high pass the sides precisely to remove bass from them

I don't understand why one would want to preserve the attack and highs of a drum's position in the stereo field, yet attempt to move it's low end to the centre. A recipe for a cluttered centre and a very disjointed drum sound.

A low floor tom would usually be tuned higher than 120hz, so no need to mono it's low end anyway.

What plugin do you use to preserve the side's low end / move it into the centre? Does Waves Centre do this with some clever FFT trickery? I'm sure I read that somewhere.

Cheers

Scorb

[BRBWaffles]

Of course it doesn't, why would you expect it to? I high pass the sides precisely to remove bass from them

I don't understand why one would want to preserve the attack and highs of a drum's position in the stereo field, yet attempt to move it's low end to the centre. A recipe for a cluttered centre and a very disjointed drum sound.

A low floor tom would usually be tuned higher than 120hz, so no need to mono it's low end anyway.

What plugin do you use to preserve the side's low end / move it into the centre? Does Waves Centre do this with some clever FFT trickery? I'm sure I read that somewhere.

Cheers

Scorb

Nearly every bass monoing plugin dumps the sides to the center. Mongoose, A1StereoControl, Sanford Bass Tightener, etc. I've actually found it more rare that a plugin for this purpose simply high passes the sides. If the choice is between removing low end content you worked hard on, or simply moving that content over a few degrees, I think most of us would opt for the latter.

[djscorb]

Thanks, will check them out. The only times I've had need of something like this was with a track with a totally decorrelated low end in mastering. The client couldn't go back to the mix, so in this extremely rare scenario, something like this might save the day.

I think people exagerate the need for making bass completely mono. It's never mattered less, and like with a lot of things audio, it gets taken to the extreme instead of being something that simply needs to be kept in check.

Same with removing lows in general. I get so much stuff in for mastering where someone's shaved off everything below 45hz (or higher!) with a 48db+ filter. No doubt because someone told them that you have to cut the lows and they took it to the extreme!

Cheers

Scorb

[mutantdog]

Sorry about the delay, I've had a lot of other stuff to deal with so this got put on the back burner. I'm not sure when i'll be able to test the other suggested plugins but they are next on the list. On top of that i plan to do a few other more "realistic" tests but I'll come back that later. Anyway, here's a visual overview of what I've done so far, better late than never...



As before, I've used a distorted wobble bass loop panned hard left (top-left image). The rest of the top row is made up of what appear to be based around some kind of side filtering. Note the similar shape curves on VUMT and A1 which (as we will see later) appear to be consistent with a resonant hi-pass or low-shelf. In contrast, Sanford BT has a smoother curve which has a less pronounced effect unless the frequency is set such that it reaches well into the mid range (top-right is an extreme example of this).

The second row is made of a selection of what i've concluded are based upon a multiband crossover type format, GStereo (bottom left) is exactly this while the others appear to use the same principle. Furthermore, I created an Ableton rack following this concept and (although not shown) the results were similar. This method differs from the side filter types in that the audio is split into two (or more) frequency bands with the the lower band having its own M/S width control (LFMaxP has a simple mono on/off selector but appears to be principally the same). My assumption is that Mongoose is probably similar to this. Clearly these have a much more absolute effect on the low frequencies, collapsing them completely to mono, LFMaxP adds a whole lot more features but that is beyond the scope of this assessment.

However, the bottom row plugins (and my Ableton rack) all had the same negative side effect of messing with the dynamics as demonstrated in the following image:



This is a before and after comparison running a simple breakbeat through LFMaxP with 12dB crossover, although the same applies to all GVST plugins and my Ableton rack. It's clear from the bottom image that the dynamic range is greatly affected, from a purely subjective perspective I found this to be unpleasant sounding and certainly not beneficial to transient preservation. I guess this type of plugin may be best suited for basslines, but should probably be avoided on beats or mixes (it's also worth noting that LFMaxP has the same effect when used in linear phase and minimum phase modes).


So next up we have a whole bunch of my experiments with side EQ (I've not included everything but tried to show some of the more interesting examples). For these I have used Tokyo Dawn's EQs although I have no doubt similar results can be achieved with any other high quality EQ plugin. I won't go into too much detail as all the relevant parameters are shown and labelled.



SlickEQ M has a dedicated monobass feature which i discussed in an earlier post. Also I experimented with side reduction using a low shelf (various types) and then a combination of both filters. As you can see, some good results were achieved with combinations. Also note the similarities between the steep II lowshelf and VUMT/A1 in the first image.





This a small selection of images from SlickEQ GE in side/diff mode. Again I've used the two different hipass filters and a couple of low shelf filters aswell as a combination of both. No EQ saturation has been used in these cases however there was no discernible difference when it was used. Note, the interesting WTF in the bottom right when activating the low-frequency lag function!





Finally, a few examples with Nova. Same sort of thing here, various hi-pass and low-shelf filters in side/diff mode. Of particular interest here is the steeper hi-pass curves, 24dB and especially 72dB (the latter being another WTF example and probably a demonstration of why steep filters like this should really be used with caution in general).



Conclusion (so far): It seems that the best all round option is a combination of both hi-pass and lowshelf side filters. The multiband type may be preferable on certain material but should be used with caution especially when anything percussive is involved. What is not apparent from the images is how they affect the perceived volume of the bass. I haven't done any tests on this but i can say from my own usage that VUMT seems to have a pleasant boosting effect which presumably coincides with the peak of the curve. I would assume that the same could be said of the other similar type curves achieved with side EQ (in particular steep low shelf).


What's next: I still plan to try the Audiority, Plugin Alliance and NuGen plugins. Also, i'm curious to try Ozone since that has many options to explore. Beyond that i want to try some more "realistic" setups, such as slightly off centre basses and a Juno style chorus bass. As for how soon this happens, it's probably best i don't make too many promises right now.



TL;DR. Just look at the pictures!

[Lesha]

Wow, thanks. Is there a free or cheap alternative to the spatial spectrogram you used?
I would like to do my own testing if I find enough time.

You could also test Stereo Channel by Sleepy Time Records.

[MogwaiBoy]

WOW - thank you!

Re: Ozone Imager. Yeah it is quite interesting because you can set the phase of the crossover (analog/minimum, linear or "hybrid") and that does greatly affect the sound. No idea what it looks like under the microscope though.

So we can definitely conclude that A1StereoControl and VUMT Deluxe have resonant filters?

Boz Mongoose is under $17 in cart at Audio Deluxe if you're keen to put that one to the test too. No pressure!

[mutantdog]

Wow, thanks. Is there a free or cheap alternative to the spatial spectrogram you used?
I would like to do my own testing if I find enough time.

You could also test Stereo Channel by Sleepy Time Records.

I'm using Flux Studio Session Analyzer, it was free as part of the Focusrite plugin collective thing a few months ago. I can't say i've seen anything else like it (perhaps iZotope Insight?). It's a really good all-round visualiser tool, although i find it a bit unstable on Win10. I'm pretty sure there's a few sellers on the marketplace here with unregistered serials (iLok, no dongle) so you might find it cheap there.

Sleepy Time, now there's a blast from the past! If its 64-bit i'll add it to the list.

WOW - thank you!

Re: Ozone Imager. Yeah it is quite interesting because you can set the phase of the crossover (analog/minimum, linear or "hybrid") and that does greatly affect the sound. No idea what it looks like under the microscope though.

So we can definitely conclude that A1StereoControl and VUMT Deluxe have resonant filters?

Boz Mongoose is under $17 in cart at Audio Deluxe if you're keen to put that one to the test too. No pressure!

I think that's the case with A1 and VUMT. As for Mongoose, if there was a demo I'd try it but even at $17 I'm reluctant to buy it.

Hey Boz! If you're reading this, I once stood on the roof of a building near an Elton John gig, I'm sure he'd support this project if you wanted to donate a copy!

[Lesha]

I'm using Flux Studio Session Analyzer, it was free as part of the Focusrite plugin collective thing a few months ago. I can't say i've seen anything else like it (perhaps iZotope Insight?). It's a really good all-round visualiser tool, although i find it a bit unstable on Win10. I'm pretty sure there's a few sellers on the marketplace here with unregistered serials (iLok, no dongle) so you might find it cheap there.

Sleepy Time, now there's a blast from the past! If its 64-bit i'll add it to the list.

Oh, I would have got it too, but I stay away from iLok.

Here is Stereo Channel in 32 & 64 bit

[Debutante]

farrrrgin WIKID graphic. Very much appreciate the effort

[MogwaiBoy]

I guess all this analysis leads to the question: where to mono out? I hear 100hz or even higher bandied around (was it David Guetta who said 250hz or something crazy like that?) but in my experience it really starts shrinking your stereo width beyond 100hz if you have big moments happening in the music (the choruses feel more wimpy etc). I'm liking more down around the sub depths, like 40-50hz to be more transparent - just so you're sure that the real super lows are mono and that's all. Some 120hz width in the kickdrum or even bass isn't a bad thing.