Focusrite Scarlett 18i20 USB Audio interface

[The Paul meister]

In addition to the subject title, it is a Third-generation 18-in, 20-out interface for Mac or PC. It's a 1U rackmount unit.

This is not an exhaustive review, but I'll post what I can from my experience.

It has all the input/output you could be looking for: 2 XLR instrument inputs for guitar, bass or line, 6 more mic preamp inputs for mic or line and 10 balanced 1/4 inch outputs. It also has i/o for midi, 2 x ADAT, s/pdif, word clock out and 2 headphone jacks.

The output is USB C, but it comes with a USB C-A cable, for plugging into normal USB sockets.

The sound quality is excellent. I have recorded bass and guitar onto my Mac and then played it out through an amp and it sounds no different to playing the guitar straight into the amp.

I would add a caveat that I have tried this interface with PC and Mac. There is virtually no background noise with Mac, but with PC there is a bit of noise coming out through the amp, or V-amp 2 in my studio. When I used it with PC, I found that the headphone output with an insert cable gave less noise.

The other main feature of an audio interface is triggering soft synths without appreciable latency. On my Mac, you don't even have to configure anything - it just gives you low latency. In Cakewalk by Bandlab on PC you can set the latency. Anything less than 10ms is fine.

It also comes with a bundle of cool software if you look online. Some of this software wasn't available when I bought it. Every few months, they add more to this free software.

Overall I am very pleased with this equipment. When I bought it, it was £400 - I think it's gone up a bit since then. Also, I imagine all the smaller Focusrite interfaces sound the same. I don't have any experience of the Clarett range other than I think they're more expensive.

Cheers, Paul

[The Paul meister]

Just to add,

I've tried this interface with a 4 string bass. I'm not sure how well it will handle lower bass frequencies from a 5 or 6 string bass.

I'm also using a Line 6 Bass pod xt. On the same note, I'm not sure if this likes a 5 or 6 string.

I'm sure with a bit of research on the internet, these questions can be resolved.

Cheers, Paul

[Wonks]

The frequency response is quoted as being 20Hz to 20kHz±0.1dB. that's quoted for both mic and line inputs.

So the fundamental of a low B bass note (30.8Hz) is within that flat response range.

You'll struggle to get a playback system to reproduce 31Hz at any volume (wide-range headphones are your best option) and your typical stage bass amp + speakers will also struggle to reproduce the fundamental frequencies of the very lowest notes on the bass, so you normally hear the 2nd and upper harmonics from the bass and the brain normally fills in the missing fundamental.

[The Paul meister]

Hi Wonks,

Thanks for finding that bit of information on the internet - I couldn't see it anywhere on the box. It's good to clarify this for me and other users.

Cheers, Paul

[The Paul meister]

Hi all,

Just to add - I'm using Logic Pro on my Mac.

Cheers, Paul

[The Paul meister]

This interface has Combi inputs for XLR and 1/4" balanced or unbalanced, ie TRS and TS jacks.

The XLR is for mics and the 1/4" is for line or instrument inputs. The guitar and bass inputs have a Hi-Z option which is selectable via the 'inst' button.

I'm not sure about the 4th generation interfaces.

Loads of information on this topic can be found by the thread I started here:

https://www.soundonsound.com/forum/view ... hp?t=94404

[Arpangel]

Interesting, have you heard the Clarett range? I'm wondering if there’s a big difference, or not.

[The Paul meister]

Just to clarify, the Hi-Z input for guitar and bass is only possible with a 1/4" jack. This option is available for inputs 1 and 2. These inputs can accept instruments eg guitar, line via 1/4" or mic XLR. The other six inputs accept mic XLR or line 1/4".

Hi-Z means high impedance which is needed for guitars and basses.

Don't make the mistake I did and plug your guitar in using an XLR as this reduces the higher frequencies.

In the thread I already mentioned:

https://www.soundonsound.com/forum/view ... hp?t=94404

Hugh Robjohns posted this: The XLR input is expecting mic level and presents an impedance of around 1.5k to 2.5k ohms. A guitar needs to see more than 500k and most hi-Z inputs present 1 Meg Ohms.

I'm not sure about the Clarett range. I haven't heard it.