SPL Crimson review – well-specified desktop audio/MIDI interface that also works with iOS

crimson_front_print square smallIf you want to construct a mobile recording system around your iPad (or even iPhone), keeping things super-portable would lead you to devices such as the iRig Pro or perhaps the the iTrack Solo. Both of these devices (and others like them) combine very decent audio recording quality with a relatively small footprint and price tag. However, compact interfaces inevitably come with a stripped-down specification and/or feature list. If you want more features and flexibility, then you need to look up the price ladder a little…

A couple of new additions might be the obvious iPad companions on the next rung or two; the Focusrite iTrack Dock and the Alesis iO Dock II. Both offer a sensible balance between audio quality, features, size and price.

Beyond that, then you get into territory of audio/MIDI interfaces designed for desktop use and which may – and, oftentimes, may not – work with iOS. The hardware may well be of very good quality but if it doesn’t work with your iPad, then it is not going to be much help for your mobile studio….

However, it is welcome to see that manufacturers of desktop audio/MIDI interfaces are now starting to pay more attention to the mobile musician and ensuring that their hardware, if not designed specifically for iOS, is at least compatible with the platform. One such manufacturer is the German-based Sound performance Lab (SPL) who have built an impressive reputation for high-quality studio equipment.

SPL have now brought that expertise into the audio/MIDI interface market.  If you are prepared to buy a higher quality, ‘combi’ (suitable for desktop and mobile use) interface that offers plenty of features and flexibility but still is pretty portable, then their Crimson USB interface and monitor controller – priced at around £400 – might be just the ticket.

The SPL Crimson -  compact(ish) audio/MIDI interface with plenty of features - and including support for iOS.

The SPL Crimson – compact(ish) audio/MIDI interface with plenty of features – and including support for iOS.

Hardware summary

Physically, the Crimson is a wedge-shaped desktop unit, measuring approximately 33 x 21 x 6 cm, and weighing around 2.7kg. As shown in the various images here, all the main controls are set out on the spacious top surface with the connectivity split between the well-stocked rear panel and the less-well packed front edge. Rather cleverly, the text labels for each connector on the rear panel appear both the right way up and up side down; this makes it so much easier to find the socket you are looking for when leaning over the top of the unit. Note also that the unit requires mains power so, while it is certainly portable, you do need a power supply while you work. One other point worth mentioning; as far as I can tell, the Crimson doesn’t pass power on you to you iPad – but then neither does it suck power from the iPad. Essentially, you get what you get in terms of the length of your recording session based upon how well your iPad’s internal batteries cope with the apps you are running.

In terms of connectivity, in essence, what you are getting is a 6-in/6-out audio interface with MIDI in/out. However, as the unit supports two pairs of speaker outputs (one pair on XLR (speaker set A) and another on TRS jacks (speaker set B)), there is also some quite neat audio routing options that allow you to switch between the two speaker sets and also to route an alternative monitoring mix to an artist (for example, a mix that takes some of the fluff out so a singer can focus on their pitching).

The Crimson's rear panel is well-sticked with connectors....

The Crimson’s rear panel is well-sticked with connectors….

Do note, however, that while the headline is 6-in/6-out, 2 of these channels in both directions are via the S/PDIF digital connectors; you actually get four analog inputs and four analog outputs (the two pairs of speaker outputs). Inputs 1 and 2 are the microphone inputs located on the rear panel and feature XLR connectors, switchable phantom power and a high-pass filter option (useful for getting rid of any low end rumble). Inputs 3 and 4 are the instrument inputs located on the front edge and are suitable for connecting an electric guitar or bass.

All four inputs have dedicated gain controls on the top surface and, while the metering is (like on so many audio interfaces) based on just a limited number of LEDs, setting levels is actually very straightforward regardless of your audio source. In addition, all four inputs have an associated, fixed gain, line-level input on the rear panel (for example, suitable for a synth output). Plug something in here and it overrides any signal coming in via the mic or instrument input of the same number.

There are other audio inputs on the rear panel; a pair of TRS jacks and a pair of RCA-phono sockets. However, these are for monitoring-only; you can mix their signals in with whatever else is getting to your main speakers outputs but they can’t be routed to your DAW (desktop or iOS) and there is no gain control so you have to adjust the level of the incoming signal at source.

By default, the two front-edge headphone outputs get the same mix of audio as being delivered to the main outputs (speaker set A) and there is a dedicated gain knob for each headphone output. Thankfully, these seems to have lots of gain so, while I’m not advocating extended listening at high levels, you ought to be able to give a drummer enough juice to hear a monitor mix over and above the sound of his own kit. There is, of course, also a large master output level knob. Again, this offers plenty of gain if required.

The top surface controls are well spaced out.

The top surface controls are well spaced out.

The remaining connectors on the rear panel are standard 5-pin MIDI in/out DIN sockets (note that there is no USB MIDI option; you will need a MIDI keyboard that features a ‘proper’ MIDI output) and the USB connector. The latter is USB 2 (for maximum compatibility) and, if used with an iPad, you will need the Camera Connection Kit to get connected.

Don’t be put off by the USB 2 as opposed to newer USB 3 format; there is plenty of bandwidth for the audio data transfers involved and, used with the dedicated drivers for OSX or Windows, sample rates up to 192kHz are supported. When used under iOS, no additional drivers are required as the interface is class 2 compliant. In this mode (which also works under iOS if you don’t want to use the drivers), sample rates up to 96kHz are supported. Frankly, if you want to record at higher sample rates than this, I’m not sure an iPad ought to be your choice of platform; I’ll stick with 24-bit, 44.1kHz thanks.

On the button

The lower-center of the front panel is dominated by an array of 12 buttons. These allow you to decide just which signals are ‘active’ at any one time as part of the monitoring system. In the main, these are fairly straightforward; tap the button to illuminate it and that signal will then be heard through the monitors/phones. These options do provide useful flexibility.

Perhaps the most interesting feature amongst the button cluster is the one labelled Artist Mode. There are a number of ways this might be used but the most obvious task is simply to provide a performer with a different mix to that being monitored by the engineer. This does require that your DAW software supports multiple outputs and that each output can be sent a different balance of the tracks recorded within the DAW (for example, in Cubase, you can do this via the Control Room options).

The rear panel lettering is displayed both ways up; very helpful if you are leaning over the top of the unit while making connections.

The rear panel lettering is displayed both ways up; very helpful if you are leaning over the top of the unit while making connections.

If you engage Artist Mode, then the standard mix comes to the Crimson via DAW outputs 1/2, while the ‘alternate’ artist mix comes via the DAW outputs 3/4… and this alternate mix is passed to the ‘B’ speaker outputs and the headphone 2 outputs of the Crimson. This is all very useful and, if you have a performer that needs to hear something very specific in their ears, it can really make a difference. In addition, you can use one of the mic inputs as a ‘talkback’ mic so the engineer and artist can communicate via the Crimson if they are located in different rooms.

Desktop friendly

I did give the Crimson a bit of a spin using Cubase on my iMac under OSX 10.9 and, while I didn’t spend a lot of time pushing the unit to it’s limits (this is a blog for mobile music making after all), I have to say that I was suitably impressed with the audio quality and overall functionality. It certainly compared very favourably to my Focusrite Scarlett 8i6 (it should; it is considerably more expensive) and the Crimson offers plenty of flexibility in terms of audio routing and monitor control.

In short, I’d be more than happy to use the Crimson as a desktop audio/MIDI interface. It will make very high quality audio recording provided you take good care of the rest of the signal chain and, if you tend to record one or two musicians at a time (rather than micing up a full band where you would need considerably more inputs than offered here), it is a powerful piece of kit.

On the move

Of course, as this is the Music App Blog, my main focus on interest was on how the Crimson might be used with an iPad as the audio/MIDI I/O hardware hub of your mobile recording studio. Hooking up my iPad Air to the Crimson was simple enough; a standard USB cable (one is not supplied with the Crimson) and the Apple Lightning-to-USB connector kit (or the CCK for 30-pin dock devices). Otherwise, all the connections are identical to using the Crimson with a desktop computer so I hooked up my powered monitors, plugged in some headphones, a MIDI keyboard, a mic and a guitar and I was good to go.

The Crimson and my iPad Air played very nicely together....

The Crimson and my iPad Air played very nicely together….

Before getting into the actual music creation process, I did do a series of routine listening tests streaming some commercial tracks in various styles off my iPad, through the Crimson, and auditioning both via my nearfields and headphones. The results were genuinely impressive and, while there are other elements in the signal chain, the Crimson certainly seems to deliver very solid, even and detailed audio. In the context of a mobile recording studio, you are going to need some pretty impressive pieces of complimentary equipment in terms of speakers and mics for the Crimson to be the weak link in your audio signal chain. And if your speakers (and ears) are up to it, it seems to chuck out plenty of level.

Red light zone

As Cubasis is my usual squeeze when it comes to iOS recording, that’s where I started in testing the Crimson. This actually proved to be very straightforward and I was able to work both with Cubasis on its own (plus whatever IAA apps I ran within Cubasis) and via Audiobus.

Using Cubasis on its own, all of the Crimson’s audio inputs and outputs became available in the Routing section of an audio track’s Inspector panel. You could, therefore, select any of the four analog inputs or, if you wanted to, the S/PDIF digital input. Equally, you could send a track out to the Crimson’s other outputs rather than just the main outputs. While Cubasis doesn’t really allow you to fully capitalise on the alternate monitor mix process (as you could with a desktop version of Cubase, for example), you could at least just send a limited number of tracks out via outputs 3/4 if your performer just wanted a bare-bones mix while recorded a new part.

The Crimson's various inputs were visible within Cubasis for selection.

The Crimson’s various inputs were visible within Cubasis for selection.

Using a combination of the Analog Input buttons (top row of the button panel on the Crimson) and the Cubasis track monitoring buttons (the button with the small speaker icon that appears on each audio track), you can choose to either monitor your incoming audio directly via the Crimson (generally best for acoustic sources and latency free) or indirectly via Cubasis (for example, if using a guitar amp sim app as an Insert IAA effect and you want to hear the processed sound) or, indeed, both. This is both easy to configure and very flexible.

Used with Audiobus, all the inputs were also easily available.

Used with Audiobus, all the inputs were also easily available.

Used with Audiobus, I created a four-lane configuration in Audiobus 2 and simple assigned one of the four analog inputs available on the Crimson to each lane. This worked very well indeed and, when you need to insert a bunch of apps between your input audio and your DAW, is a very slick way of working.

Both with and without Audiobus, I was able to record 4 audio tracks simultaneously into Cubasis. If you did want to record several sources at the same time then this is perfectly possible. Equally, I had no problems routing MIDI data to Cubasis (or any of my usual synth apps) from the Crimson.

A four-lane configuration within Audiobus allowed me to define a lane for each of the four analog inputs.

A four-lane configuration within Audiobus allowed me to define a lane for each of the four analog inputs.

While I don’t use Auria as often as I do Cubasis, I did also give this a bit of a run through just to verify that the various inputs and outputs could be accessed and worked as advertised. As with Cubasis, I had no problems here; the Crimson worked well and could easily be used as a I/O solution for those working with Auria.

One final point is worth repeating here. Throughout my testing, I was never less than impressed with the audio quality on offer with the Crimson. Both the mic preamps and the instrument inputs would appear to be of high quality and that is matched my some equally impressive gain that is available on all the inputs and the outputs. Add in the flexibility offered by the various monitoring configurations and this is a seriously good piece of hardware.

In summary

If you want ultra-portable in your iPad-based recording setup, then the SPL Crimson might not be your very first choice of audio/MIDI interface. That’s not to say that it is not portable – it is still pretty compact – but, once you have added all the other gear you need to make your mobile studio, you are probably talking a significant rucksack rather than a small shoulder bag.

The Crimson's MIDI input was visible in all my favourite iOS synths as with Thor shown here.

The Crimson’s MIDI input was visible in all my favourite iOS synths as with Z3TA+ shown here.

However, what the SPL lacks in major smallness, it makes up for in major audio quality; this is a seriously good audio interface and the four analog inputs are very impressive. The physical layout of the controls is spacious and sensible, while the flexibility offered by the various audio routing options would be very welcome for those using more than one set of monitor speakers for assessing mix balances.

Given the c. UK£400 price tag, the Crimson might be a bit of a stretch for the first-time audio/MIDI interface buyer. However, if you are looking for a step up in quality from something at the more budget-end of the market – and particularly if you would like an interface that can do double duties with a desktop system and the iPad – then the Crimson has a lot going for it. There are interfaces in this price bracket that offer greater numbers of analog inputs (and would therefore be better suited to mic’ing up a full band, for example) but SPL have struck an excellent balance here between I/O and monitor management.

For iOS musicians – obviously the focus here on the blog – the plug & play nature of the Crimson is a definite plus. I had no problems using the unit with my iPad Air nor with any of the audio/MIDI apps I used in combination with it. The SPL Crimson is a thoroughly well-designed piece of kit and, if your budget can stretch to the asking price, then you will get a quality interface in return.

SPL Crimson

In the UK, the SPL Crimson can be ordered directly from Hand-in-Hand Distribution who were kind enough to loan me this unit for review. It is also available from Amazon UK and other good music technology retailers.

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    1. One small comment – the synth in the picture seems to be zeta, not thor. And a question – does this thing also charge the iPad? If not, what interface does?

      Many thanks!

    2. Hi Pete… thanks for this; typo corrected. The documentation makes no mention of the Crimson supplying power to the iPad and, when you do connect up, the iPad doesn’t shown the usual ‘charging’ message so I guess the answer is no. Good point though so I’ll add a sentence in the main text to highlight this.

      The new Focusrite iTrack Dock does supply power to your iPad… so this might be a solution. I’m pretty sure the Alesis iO Dock II also does this…. Hope this helps? best wishes, John

      • Hi John,
        Just bought a SPL Crimson, tried to connect it to my Ipad 4 and Iphone 6, however could not get it to respond (both ios device is on 9.2 firmware) my lighting to usb camera adapter is legit, do you have have any idea how to solve this problem? There’s not much info on the internet about this issue. Much appreciated!


    3. Thanks, that was indeed helpful!

      • BTW, I think I have a loan review unit of the iTrack Dock on route from Focusrite so, all being well, I’ll be doing a review of that next week at some stage…. best wishes, John

    4. Rick Nance says:

      I don’t see any reference to the RME Babyface. Is the audio quality much less than the Crimson?

      • Hi Rick, I’ve not had a chance to do a side-by-side with the Babyface. There are some really good audio interfaces available now for (fairly) modest sums of money and RME do have an excellent reputation. Once you get beyond the most very entry-level devices, if you are talking about something at the level of an iPad or basic desktop ‘project studio’, I think it becomes as much about the overall feature set of the interface as the absolute audio quality…. Used with some care and common sense, it is probably going to be other elements of the signal chain (mics, room acoustics, etc.) that will play a more significant role in defining the quality of the results? Best wishes, John

      • Recomment RME’s Product on iPad, you can get more control.

    5. I think RME Babyface Pro is more suitable for iPad.
      1. got all features that crimson have
      2. more compact
      3. more flexible routing on TotalMix Fx App
      4. usb powered

      If you had used TotalMix Fx App, you’ll never want any other audio interface.

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