Yes, this is going to be a review of SilQ, a new equalizer app from TonApp AS… but first, bear with me for a little bit of (hopefully useful) EQ background. When it comes to audio processing – whether for live sound or for use within a recording context – there are some key effects/processing options that every musician/mix engineer needs in the tool kit. Many of these are not the ‘ear candy’ creative sort of effects but more the everyday and every mix sort; just essential tools of the trade.
Compression and reverb would most certainly be in this particular ‘essentials’ class but the other obvious candidate is equalizers – EQ – and pretty much every DAW/sequencer worth the name will include one or more EQ tools within its effects collection. For us iOS musicians, there are also third-party apps that offer EQ tools and apps such as Level.24, MasterFX, Audio Mastering and Final Touch, amongst other things, also offer some quite sophisticated EQ options.
EQ comes in all sorts of varieties. Simple ‘bass’, ‘mid’ and ‘treble’ controls (as you might find on a guitar amp or a hi-fi system) are easy enough to use but lack the precision required for much studio-style work where you might need to target very specific frequencies for cutting or boosting. That precision tends to come in parametric EQs. As well as providing you with ‘high pass’ or ‘low pass’ options, if you have access to a multi-band parametric EQ, you usually get one or more ‘fully parametric’ bands. These allow you to set the exact centre frequency, the amount of gain change to be applied at that target frequency and the bandwidth (often termed Q but essentially a measure of the frequency range around the centre frequency over which any gain change is applied).
The bandwidth/Q control is important as it means you can apply the EQ over either a broad frequency range (useful for more gentle/transparent results) or to a very (sometimes very, very) narrow frequency range (often useful for corrective applications if you need to remove a problematic frequency; for example, noise caused by mains hum). However, learning how to use parametric EQ can, for newbie musicians and/or recording engineers, be quite a challenge (an app like hearEQ can help here…. it can get your ears trained to recognise specific frequency ranges and this can help when making mix decisions).
Conceptually at least, a further EQ type is perhaps easier to get your head around; the graphic EQ. In fact, you can actually think of this as a series of parametric EQs but where the centre frequency and the bandwidth have been pre-set by the manufacturer for each EQ band and you, as the user, simply have access to the gain controls for each band on the EQ. The degree of finesse that the processor then offers is, to a large extent, dictated by the number of EQ bands provided and how close the fixed centre-frequency of each band is.
For example, if you have a 7-band graphic EQ, where those bands span over the typical 20Hz to 20kHz range, each band is going to cover quite a range of frequencies. This is fine if you need to make fairly broad EQ changes (a gentle nudge of the lower-mids, for example) but perhaps of less use if you want to cut/boost a narrower frequency range.
Obviously, the more bands you have in your graphic EQ, the better and, in the studio context or in a live sound rig, 16-band, 32-band and even 64-band EQs – both in hardware or software formats – are not uncommon. And, when you consider that many of these devices may well be stereo in nature (that is, you get, for example, 16 bands for both the left and right channels), that is a lot of faders (gain controls) to get your hands on.
Join the bands
Which is, of course, where SilQ Equalizer from TonApp AS (the develop behind the excellent GuitarCapo app) comes in. SilQ provides a 32-band stereo graphic equalizer is a convenient and easy-to-use, iOS music app format. The app is a 3MB download, requires iOS8.4 or later, is iPad only and, for the launch period, is priced at just UK£3.99 (40% off what will be the eventual pricing). From the off, the app has support for Audiobus and IAA and it also includes a recording facility so you can record the results of your processing directly within the app if you so wish. AudioShare support then allows you to share those recorded files with other apps.
The main controls for SilQ are contained within a single screen but, as can be seen from the various screengrabs, the display is dominated by two groups of eight virtual faders (the top row for the left channel and the bottom row for the right channel). Along the top of the screen are four ‘tab’ buttons that allow you to switch between displaying four different sub-sets of the 32 bands; bass, lower mid, upper-mid and treble…. so, as you move through each of these tabs, you can access all 32 bands for both left and right channels.
There is a strip of other controls that run down the right edge of the display. Usefully, these include both Bypass and Mute buttons, however, there are also four buttons that allow you to ‘solo’ each of the four main frequency group ranges. This is also useful if you just want to focus in on the processing you are doing in, for example, the bass or treble ranges.
Other buttons allow you to reset the faders, load/save presets and to trigger the internal recorder. This section of the display is completed with faders for setting both the input and output levels.
The gain faders themselves are chunky enough and easy to use. Thankfully, the centre frequency for each band is indicated as the top of each fader. You can apply +/- 20dB of gain in each band (which ought to be plenty for most applications) and the current amount of gain +/- from the zero (flat) point is also given as a numerical value at the top of each fader if you need to see the precise values being applied.
Taping the menu button (located top-right) simply allows you to find the background audio switch and has links to the user manual and website. The manual is worth a read but, as the app is actually very simple to operate, it is also fairly concise.
Positioned in between the upper (left channel) and lower (right channel) faders are a ‘reset this channel’ button and an ‘unlink’ button. The latter allows you to separate the behaviour of each left and right channel so you can apply different gain values to left/right sides of the stereo image. While most of the time you might use each frequency band in its linked mode, there are occasions when you need to process left/right channels independently and its good to have that option.
Not fader away
While there is always some musical and/or audiophile decisions to be made about what EQ processing might be required for a particular sound or mix (and the app can’t help you with that), the actual process of applying EQ changes with SilQ is very simple; just find the band or bands you wish to tweak and start sliding the faders. As you get into this kind of work, that Bypass button really does come into its own as you can quickly A/B your sound with and without the EQ processing just to be sure that you are actually making things better rather than worse.
However, having 32 bands to play with does give you quite detailed control and, in that context, SilQ is a pretty powerful tool for shaping a sound or mix providing you apply a bit of common sense and don’t overcook things. As a rule of thumb, EQ cuts can often sound more natural than EQ boosts, particularly if using big gain changes. Equally, if you are going to boost, try and do it over a few consecutive bands for a more natural result. None of this advice is specific to SilQ though – it would apply to any EQ – and SilQ just does what you tell it in a very uncomplicated fashion.
In use, the app really is a bit of a doddle. It worked very well within Audiobus during my own testing on my iPad Pro/iOS9.1 test system. It also seemed solid within IAA (I tested using Cubasis as my IAA host) and the only qualifier is that, at present, there isn’t an IAA ‘quick switch’ button to get back to your host. If I let my iPad go to sleep while in IAA mode, I also had to wake up the connection between SilQ and Cubasis but this is something I’ve experienced with a number of IAA apps so I would not like to say it is a SilQ issue; it could well be a Cubasis or more general IAA issue. It certainly isn’t a big deal and easily worked around; don’t let your iOS device go to sleep :-)
In terms of the sound, lots of geeky audio engineer types will have some EQs that they like and some that they don’t; they do the same fundamental job but they ‘sound’ different. In hardware and software, this will undoubtedly come down to just how the circuits (real or virtual) are designed but, in applying SilQ to a range of different sources – drums, guitars, bass, synths, vocals and full mixes – there wasn’t anything that struck me as unpleasant about how it sounded. Indeed, I’d happily use this tool for both corrective and creative uses in my own iOS-based music projects. As the Ronseal advert goes, it does exactly what it says on the tin. No fuss, no drama, just easy-to-use EQ processing… experienced iOS musicians will welcome a detailed graphic EQ tool while music tech newbies will appreciate the straightforward user experience.
In the (development E) Q?
The UI design of SilQ is very pleasing on the eye and the controls easy to operate. And, while I tested on the larger iPad Pro screen, I can understand the adoption of the ‘four banks of eight faders’ approach used here; if you were on a standard or ‘mini’ iPad, that might be plenty to deal with in a single screen.
However, whether it’s an option to show all 32 faders in a (much!) narrower format (it would, I think, work OK on the iPad Pro), or an option to at least see the settings for all 32 bands in a narrow mini-graphic strip running above each set of faders, or even the possibility of both these features, I think that would make a great addition. Being able to see the full EQ curve that your set of 32 faders are creating all at the same time would be a big help…. and the graphic could also highlight which of the sub-set of eight bands you are currently working with in the main part of the display. Maybe that’s something TonApp might consider for an update at some point?
The one other option that might be nice (and, I suspect, easy to add) would be a global link/unlink button so you could unlink all the left/right channels in one tap rather than, as at present, having to do each band individually.
That aside, there is little not to like about SilQ. It is a powerful, but easy-to-use, EQ tool that works with a minimum of fuss. It really could be an app for every serious iOS musician to consider and, whether it’s for every day or just occasional use, at the launch price of just UK£3.99, it is yet another example of just how much value you get from iOS music app software.
SilQ sounds good, does its job and is seriously inexpensive…. If you need some additional EQ tools, SilQ comes highly recommended.