zMors EQ review – Sven Braun sets the tone with his first iOS audio processor in an AU format

Download from iTunes App Storezmors eq logo 1I’ve reviewed Sven Braun’s zMors synth and zMors Modular here on the Music App Blog in the past and covered the various updates to both apps as their specs have been refined and expanded. Both apps are very cool and, for geeky synth-heads, as a modular environment, zMors Modular is a lot of fun. Both apps are, however, seriously good music tools for the iOS musician.

So, given Sven’s pedigree, I’m more than interested in any new iOS music apps he might have to offer…  so it is with some excitement that I (we) can welcome the latest release; zMors EQ. There are, of course, no prizes for guessing what this apps about. Yep, it’s an EQ audio processor app….  However, zMors EQ does have some interesting features that will, I’m sure, get the fully-committed iOS musicians attention.

Essentially, what you are getting here is a 5-band EQ with various modes for the different bands and a rather elegant-looking UI that gives you a clear visual cue as to the EQ curve you are applying. So far, so good…  but perhaps the highlight features are (a) that the app includes mid-side options (rather like M/S Proc that I reviewed last week) and (b) it is available as an AU (v3) plugin format only. The app includes an ‘analog noise’ feature (to give the EQ some analog character) and automation from within your AU host.

zMors EQ - a 5-band AU-only EQ plugin for iOS.... and seen here running within Cubasis.

zMors EQ – a 5-band AU-only EQ plugin for iOS…. and seen here running within Cubasis.

In terms of other basics, the app requires iOS9.3 or later, an iPad 4/iPad mini 2 or newer, is universal, and is a 1MB download. Launched at just UK£3.99/US$4.99, it is also inexpensive enough to tempt almost any iOS music maker.

I think Sven’s decision to go down the ‘AU-only’ route is a very interesting one and, when you combine it with the news last week that Klevgränd Produktion have updated six of their iOS music apps to offer the new AU v3 format, it does suggest that developers are (finally) gaining some confidence that the AU framework is now a viable (and reliable?) proposition under iOS. Anyway, good luck to Sven for taking the plunge and helping to push the AU framework forward in this way.

Join the EQ

Before digging into the app, let me start with a short pre-amble. When it comes to the most important processing options required to build a solid mix, EQ and compression are the key tools. Yes, you can add all sorts of other processing options to create ambience or for ear candy but setting your tonal balance and the relative levels/dynamics of each instrument within your arrangement are vital in developing a clear, well-balanced, mix.

Anyway, the point I’d like to emphasise here is that if you are just starting out in the ‘science meets art’ world that is music mixing, you could do a lot worse than getting stuck into some frequently repeated practice using compression and EQ.

zMors, the merrier

So, if EQ and compression are the key processing building blocks for constructing a solid mix, then having a few choices in this area is generally going to be a good thing. While all the decent iOSDAW/sequencer apps ship with stock EQs and compressors, or offer further choices through IAPs, its great to have some choices as each EQ or compressor has its own character….

zMors EQ also ran smoothly in other AU hosts such as AUM shown here.

zMors EQ also ran smoothly in other AU hosts such as AUM shown here.

And now, with zMors EQ supplied in an AU format, providing you have a suitable AU host (for example, MultitrackStudio for iPad, AUM, Garageband for iOS or Cubasis), and relatively recent iOS hardware, you can now put a plugin onto multiple tracks within your iOS AU host just like is possible in the desktop music production environment. This is obviously an advantage over something in, for example, an IAA-only format, where one instance per project is all you will have available.

Plug it in

While I gave zMors EQ a quick test drive in both MultitrackStudio for iPad and AUM (without any problems), I did most of my own testing within my usual DAW/sequencer of choice; Cubasis. I had no technical issues during testing and, while I don’t think there is any such thing as bug free software, zMors EQ certainly seemed pretty solid in use. And, of course, it was possible to have multiple instances installed within the same Cubasis project :-)

Used in its most simple fashion, zMors EQ is a five-band EQ processor with, as a default setup, a low-shelf band, three parametric bands and a high-shelf band. Frankly, at the current asking price, that’s would still represent a bit of a bargain but, in fact, you can change these various bands between different modes (bandpass, notch, high-pass and low-pass options are included) and, over and above that, zMors EQ has a few other tricks up its sleeve, not least that it also offers a mid-side (M/S) mode that can engaged via the M/S button located bottom-left of the interface.

The single horizontal slider performs multiple functions within the app.

The single horizontal slider performs multiple functions within the app.

There is a set of four further buttons located at the base of the display – level, Delay, Pan and Noise – and these change the function of the single horizontal slider control immediately above the buttons. Level sets the output level from the plugin while the Pan control does exactly what you would expect…  Well, it does when used on a stereo source (or, for example, when placed on the stereo output buss) but I’m less sure exactly what’s happening when it is applied to a mono track.

The Noise control adds a modest amount of emulated analog noise to the signal. I found this to be pretty subtle (which is probably a good thing) but, as one element that gives specific classic hardware EQs their character is their ‘noise’, I guess its nice to have the option to ’emulate’ that here…. it’s certainly something that some of the better desktop EQ plugins also attempt to do.

The Delay control allows you to delay either the left or right channel signal by up to 1024 samples. Again, I’m not exactly sure what the processing chain is doing here (hopefully, Sven will provide a PDF manual at some point) but it certainly seems to influence the stereo image of a track. As with any processing of the stereo image, this is perhaps something to use sparingly.

Clean sweep

I’ll get to the M/S options in a minute but, in its more conventional role as a five-band EQ, zMors EQ has a lot to offer. If you tap and move any of the numbered circles, that selects that band for editing. Much of this can be done by simply dragging to change the gain (up/down) or frequency (left/right). The bandwidth (Q) setting is then adjusted by the single, multi-purpose, fader beneath the main EQ curve display. usefully, this changes colour to match the currently selected band so you know exactly what you are working with.

Note that the app appears under the 'Moon:EQ' entry within the AU selection panel in Cubasis....

Note that the app appears under the ‘moon:EQ’ entry within the AU selection panel in Cubasis….

My only other comment about the interface here is that I would have liked the option for selecting a band by simply tapping on the appropriate numbered circle. At present, the surest way to select a band is by tapping and moving it….   but that might not be what you want to do once you have set the gain/frequency and, for example, just want to adjust the Q setting. Double tapping resets the band andI’d perhaps have liked this as the ‘select a band’ gesture with, perhaps, ‘tap and extended hold’ to reset?

The option to set either high/low shelf or high/low pass for the top and bottom bands is good and provides useful flexibility. The Q values allow you to apply broad boosts/cuts (good for more transparent results) while the highest Q value (10) produces a fairly sharp boost/cut for the parametric bands. This is plenty for cutting out most problematic frequencies but it would still be great to see higher Q values available for even more surgical cuts. That said, you do also get a ‘notch’ mode and this does offer more extreme (narrow) cuts if required.

Each EQ band can be switched between a number of different modes including a 'notch' mode for dealing with very specific frequency ranges.

Each EQ band can be switched between a number of different modes including a ‘notch’ mode for dealing with very specific frequency ranges.

That said, zMors EQ is still a very close to a Swiss Army knife in terms of EQ on either a single channel or a mix buss….  and it certainly sounds the part. I felt it was clear and pretty transparent (if you avoided using the Noise option) and, as a general purpose EQ used within Cubasis, it also seemed to be pretty low impact in terms of CPU load. That’s a good thing for a processor that could see multiple uses within a single project. Cubasis’ own StudioEQ only offers four-bands and, while it is more than acceptable, zMors EQ is undoubtedly the more flexible of the two.

A bit on the side

I spent a bit of time talking about the basic concepts behind mid-side processing when reviewing M/S Proc recently so I’ll not repeat that here (just click over to that review if you want to read). With zMors EQ, when you toggle on the M/S mode, what you effectively get is two five-band EQs in one plugin; one to EQ the more central portions of the stereo image and the other to process the left/right edges of the stereo image. Obviously, this is something that would make most sense when applied to a stereo track (although don’t let common sense get in the way of experimentation) and I did my testing by sticking an instance of zMors EQ on my Cubasis project’s main stereo output bus.

One application of M/S processing is in mastering when you might set the EQ for the sides.....

One application of M/S processing is in mastering when you might set the EQ for the sides…..

Once in M/S mode, you can toggle between the control sets for the ‘mid’ band and ‘sides’ band by using the Mid and Side buttons that get added to the bottom-most strip once you have switch to M/S mode. The active control set is displayed in colour while the EQ curve for the other set is shown in grey in the background. You can, therefore, always see the EQ curve for both the mid and sides at the same time as you fine-tune your settings.

.... somewhat different from the EQ of the mids to enhance the stereo image.

…. somewhat different from the EQ of the mids to enhance the stereo image.

In terms of M/S EQ, one of the obvious applications is in ‘mastering’ your stereo mix….  and this is, of course, something you can do in either a separate app (such as Final Touch or Audio Mastering) or, if you prefer, by tagging a few apps into your main stereo output of your DAW…. With the latter, you are effectively mastering your mix as the last bit of the signal chain of the mix process itself.

However you choose to go about it, zMors EQ’s M/S option has some thing interesting to offer if you have (a) the confidence in your own mastering skills and (b) the common sense not to push things too far. One common M/S EQ mastering trick is simply to add a little extra top-end EQ to the sides while perhaps adding a little bottom end to the mid channel signal. This can make the kick/bass feel a little more solid (they are usually panned to the centre) while adding a little high-end sizzle to things such as guitars or keys (which are often panned towards the sides) and therefore give the overall stereo image a little more width and sparkle.

Without making any claim to significant mastering skills, this was a task that zMors EQ was more than capable of undertaking. With all the usual qualifiers about ‘less is more’ when it comes to mastering processing, I was easily able to tease just a little more ‘stereoness’ and ‘air’ out of a couple of mixes by applying a suitably subtle dose of zMors EQ in M/S mode. Incidentally, if you don’t trust yourself to apply M/S eq to your whole mix, then try the same trick on something like a tinkly synth arp; it can really enhance the stereo image.

This M/S trick is also one that can work well with an individual sound source such as a stereo synth.

This M/S trick is also one that can work well with an individual sound source such as a stereo synth.

M/S processing is somewhat specialised stuff and, while I think my own purchase of the app would be based upon its usefulness as a standard stereo EQ processor, the M/S option is great to have and, as far as my own testing goes, seems very effective.

Do you want zMors?

Of course, you might already have a number of EQ apps available to you or be pretty happy with the EQ offered by your DAW/sequencer. So, do your need to add zMors EQ to your app collection? Well, at the launch price of just UK£3.99/US$4.99, this is certainly a very affordable EQ option. As noted above, there might be some scope to fine-tuning the gestures required to select and operate the multiple bands, and a PDF manual would be great to see (especially for those new to the whole concept of EQ and M/S processing), but this is a very capable – and very useful – processing tool.

If you are specifically interested in M/S processing, then the M/S Proc review is worth a read as a comparison with zMors EQ but do bear in mind that the latter is also a conventional EQ. A comparison with SilQ is also interesting but, as a graphic EQ, SilQ is a somewhat different beat and, indeed, the two would complement each other very nicely in an audio processing app toolkit. Remaster is also worth a look and, while it doesn’t offer M/S options, it does include a compressor and is also supplied in an AU format.

With five flexible bands, zMors EQ offers a very respectable level of tonal control for almost any EQtask.

With five flexible bands, zMors EQ offers a very respectable level of tonal control for almost any EQtask.

In short, however, unlike synths and drum/groove machines, we don’t yet have a surfeit of dedicated EQ app under iOS. As such, zMors EQ – with its flexible control set and M/S options – ought to prove popular. Auria Pro users might well have something just as capable available ‘in house’ but, compared to most of the ‘stock’ EQ plugins supplied with other iOS DAW/sequencers, zMors EQ would fair very well…  providing, of course, you have the capability to run the AU format.

In summary

It’s great to see AU starting to gain some traction on the App Store and, for some die-hard iOS music app addicts, that might well be reason enough to support Sven Braun’s zMors EQ and download the app. However, providing you are ready for AU, this is most certainly an app that can do a good job. The five-band format is more than enough for most routine EQ duties and, as far as my own testing goes, zMors EQ seems to come with a pretty modest CPU load….  which is great for a plugin that you might well insert of every track on a project.

OK, so that’s your AU formatted EQ sorted….   Although I’m aware that Sven already has plans for features to add the zMors EQ including some presets, I wonder if the next target is zMors Compressor? While there is already AU competition for that from Klevgrand, it would certainly be good to see. Fingers crossed at this end :-)

zMors EQ

Be Sociable; share this post....


    1. Rodrigo Fróes says:

      Hi there! I’m starting to record my own music in my iPad (4) and I see lots of people talking about how apps like zMors, SilQ etc. work well in Cubasis. The thing is, I’ve been thinking about purchasing Auria Pro instead. Is it possible to use these apps as plugins within Auria Pro the same way you do in Cubasis? Thanks a lot and greetings from Brazil!

      • Hi Rodrigo…. In terms of plugin formats, iOS has two; IAA and AU. IAA has been around for some time and lots of 3rd party audio processors and virtual instruments support the format. Both Auria Pro and Cubasis support it. the downside of the format is that you can only run one instance of any IAA app at a time….. AU is a new format for iOS…. There are fewer apps currently available that support the format but that number is increasing. Cubasis currently does support AU but Auria Pro, as yet, does not….. The other factor to consider in your choice is perhaps more to do with how well either app might run on your iPad 4….. Any DAW/sequencer, if you build a complex enough project, will eventually reach the limits of the hardware…. But do check the current hardware recommendations for both apps – and perhaps seek advice from other users on the same hardware as you – before you make a final decision. Hope this helps? Best wishes, John

    2. Rodrigo Fróes says:

      Hi there, John! I’m sorry, I just saw your reply to my question here, I don’t know what happened; if I had seen it sooner, I would have already said thank you. Your answer was very informative and the essential difference between AU and IAA became extremely clear. I ended up using Cubasis after purchasing Auria Pro and realizing that, well…it crashes every 3 min. in my iPad 4. But Cubasis has been working great while I’m recording my first record, so everything’s fine! Thanks once again and get some music made!

    Speak Your Mind