The AUFX:Space music app is the first dedicated iOS reverb effect app I’ve reviewed for the blog. Produced by Kymatica, it is the first of a series of effects apps that are in development.
While reverb and delay effects are built into many iOS music apps (DAWs, synths, guitar amp sims, etc.), as AUFX:Space’s reason for being is reverb, it’s perhaps worth considering some basics of effects like reverb and delay to set the review – which I’ll come to asap below – into a broader context…. but feel free to skip a few paragraphs if you don’t need a ‘digital reverb 101’ introduction :-)
Making space (or a very brief introduction to reverb and delay effects)
Even those new to the world of multitrack recording will appreciate how things can sound very different in different spaces – small rooms, large concert halls, a concrete tunnel, a glass covered stairwell or an industrial hanger – each has a distinctive ‘ambience’ created by the size of the space, the objects within it and the materials from which it is constructed. When we listen to sound in these different spaces, we perceive that ambience as an echo (or delay) and reverb (essentially the same as echo but where there are multiple reflections coming back to you more quickly so you don’t hear the individual echoes as they are reflected from surfaces close to your listening position).
Reverb and delay can be added to recordings artificially through effects processors. Indeed, given that most of the instruments in a typical band recording are close mic’ed (that is, recorded with the microphone position close to the sound source so the audio is dominated by the sound source itself and contains little of the ambience of the room), one of the key skills involved in making the various individual elements (drums, bass, guitar, keyboard, vocals, etc.) feel like they are all sitting in a coherent space is the use of reverb and delay effects.
This is also one of the things that can set a ‘home’ studio recording apart from something crafted by an experienced mix engineer in a half-decent pro studio. The latter generally has access to better quality effects units (these days mostly in a digital format, whether housed in a bit of studio hardware or purely as software within a desktop computer) and, through experience, has a better sense of what might work and what might not.
While you can’t overcome the experience factor without putting in the hours, providing you are willing to stump up the cash, access to high quality reverb and delay effects has never been easier. Most DAWs – desktop and iOS variants – include versions of these effects, although some are better than others. Equally, other music technology manufacturers make hardware and software versions that you can buy separately; you pay your money and you take your choice.
For iOS musicians, perhaps the biggest catch is that these effects – and reverb in particular – can be a bit processor hungry. On an iPhone or iPad, this is not a luxury that we can always afford and, as a consequence, top-notch reverb is not something you will find in many iOS music apps, or if you do, it is something that you have to use sparingly to avoid it being the only thing you can run before your iDevice goes into CPU meltdown.
All of which is rather a long-winded way of saying that we could do with some more choice when it comes to reverb effects under iOS. And, given that the typical music making workflow on an iDevice has to be somewhat different from that on a desktop computer system (those pesky CPU limits are one factor but not the only one), these reverb apps need to (a) sound decent, (b) be flexible (produce a range of reverb types), (c) programmed so they can fit into a typical iOS audio workflow and (d) not hog too much in terms of CPU resources.
That is, of course, a pretty tall order….
Ambience in an app – AUFX:Space
So what about AUFX:Space then? The app is a dedicated reverb effect and, as it includes Audiobus support from the off amongst other standard iOS audio protocols, we know it will already go a decent way towards achieving (c).
Usefully, the app’s main screen – which is functional rather than flash – includes a CPU usage indicator. It’s not clear whether this is just the CPU usage of the app or the overall device CPU usage but, given that my Cubasis CPU meter was generally well above this, I suspect the AUFX:Space value is just for the app itself. Either way, in my testing for the review with a 3rd gen iPad, I was generally seeing figures of around 10-12% (it seemed to vary depending upon the settings elsewhere within the app). I’d see this as a pretty acceptable response to (d) although, obviously, it will depend upon exactly what else you are asking your iDevice to do at any given time.
In terms of (b), the app offers you plenty of control over the reverb effect. Adjusting the Room Size, Scale, Pre-Delay, Color and Damping controls allow you to create a wide variety of virtual ‘spaces’ and the list of presets clearly demonstrates what is possible. Further variety can be added with the low-pass and high-pass cutoff and resonance controls. All the controls can be tweaked on-screen or, if you prefer, via MIDI and there is a straightforward MIDI Learn feature built into the app if you want to link it to a suitable hardware MIDI controller.
Running a few different sound sources through the app demonstrated that, while perhaps not in the same league as a top-of-the-line Lexicon or other (very expensive) classic reverb, it is certainly very useable and better than most of the default reverbs offered in your average iOS DAW. It can go from very tight, small rooms right up to huge (really huge!) spaces; sound designers could have some fun with this. And the sound itself, little or large, is very good indeed so that’s a tick for (a) as well.
Fix it in the mix
Given that reverb is a key effect in the recording and mixing of music, I was interested to see just how easily the Audiobus support made it to use AUFX:Space in a recording workflow. Placed in the Audiobus Effect slot, I was easily able to pass an audio signal from either a mic or another app in the Audiobus Input slot through AUFX:Space and onwards into my DAW (in this case I was using Cubasis). I could then record the signal with the AUFX:Space reverb applied.
It’s worth making a brief comment about latency at this point. Using a mic input or just a DI’ed guitar (that is, no complex app sat in the Input slot and also hogging some processing time), the latency between my audio input and the processed signal appearing at the output was negligible. This suggests that AUFX:Space is pretty efficient in terms of its processing. However, if I ran a guitar amp sim as an Input app prior to AUFX:Space, by the time both of them had done their stuff, I did begin to notice a little bit of audio lag; not unworkable but certainly there. Obviously, if you are recording a sound source via an audio I/O device that also offers direct monitoring, then this would not be a real issue but it might be distracting otherwise and if you are also using a processing-intensive input app.
Send in the ‘verb
Of course, in a recording context, reverb tends to get used as a send effect (added after recording and ‘blended’ with the dry signal to create the required level of ambience) rather than being added while recording. This is particularly true of vocals and, of course, it gives you much more control over the amount and type of reverb you eventually use as you can reserve final judgment until the mixing stage.
Unlike the desktop world, where there are well established protocols such as VST and Audio Units that allow third party developers to create effects that ‘plugin’ to desktop DAWs (that is, they work inside the DAW as if they were part of it), iOS hasn’t really got to that stage (although Auria does offer a series of 3rd party plugins as IAPs).
Audiobus does, however, provide a workaround, albeit a rather clunky one compared to how this can be achieved in a desktop DAW. Given that some iOS DAWs – Cubasis, for example – can now be used as Audiobus Inputs as well as Outputs, it is possible to have your DAW sat in both slots. You can then send audio from the DAW acting as an input, through the Effect slot (in this case, holding AUFX:Space) and then back to your DAW as it also occupies the Output slot.
Providing your DAW can cope with the routing involved, you should, therefore, be able to add AUFX:Space to audio already recorded in your DAW. I tried this with a vocal track within Cubasis and it worked fine. I had to solo the track I wanted to apply the reverb to and set up a second audio track to record the processed audio onto. Once the recording was made, I then had two tracks; the original ‘dry’ track and the newly recorded ‘wet’ one that contained the same audio but with a dose of AUFX:Space reverb added.
Before monitoring the end result, I had to remove the Input slot instance of Cubasis and AUFX:Space from the Effects slot. Then, however, I could audition my entire Cubasis project and, by setting the channel levels of the ‘dry’ and ‘wet’ versions of the vocal to suit, I could blend in as much, or as little, of the reverb as I wanted. This is perhaps not an ideal workflow but it is perfectly workable.
In experimenting with this process, one (minor?) additional feature in AUFX:Space would have been helpful; a bypass button. While the app does feature an on/off option (located top-left), turning this off disables both the input and the output of the app rather than disabling the processing and passing the input signal directly to the app’s output. Equally, you could just set the Dry/Wet balance to zero, but a dedicated bypass button would be nice. Maybe that is something that Kymatica could consider adding to a future update?
[As an update, Jonatan Liljedahl, the main man at Kymatica, contacted me after this review was published to say that a bypass button is in the pipeline for a future update – good stuff:-) ]
AUFX:Space is an interesting app. It has a clean and functional interface and, with Audiobus and MIDI support included, it is very easy to use whether that’s for processing live audio or, using the kind of workaround described above, in a sort of ‘DIY send effect’ approach. In terms of audio quality, to my ears at least (and this can be a very personal thing), AUFS:Space is well ahead of many of the reverb effects bundled with popular music apps (although Auria’s various IAP reverbs would make an interesting comparison).
There is, however, one final point worth noting. If you are an iOS musician you could, of course, having read this review, now nip off to your local coffee shop and buy a medium sized latte (or whatever caffeine format your body craves). Alternatively, you could spend the same UK£2.49 on AUFX:Space. Even a half-decent reverb for the price of a coffee is, to anyone with a few years on their music technology clock, something that is difficult to believe. AUFX:Space is a bargain and I’d like to suggest that the creative musician within you will thank you for missing out on that coffee today and checking out the app instead :-)
AUFX:Space is well worth checking out and I’m already looking forward to seeing (and hearing) what developer Kymatica might have in store for other apps in the AUFX series.
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