Before I get into the Jet City JetStream ISO12, let me give you a bit of background on how I usually record guitars. Often I use an older-model AxeTrak isolated speaker cabinet by JLH Products. It’s a neat little unit and I’ve got a lot of use out of it, and I do recommend it (especially later versions which have more features), but it has a few limitations that I have to work around. First of all, it has a small 6-inch speaker which, though carefully voiced, is still, well, a tiny speaker in a tiny box. Secondly, its internal mic is inaccessible and immovable (later models have a moveable mic via a thumbscrew, but that doesn’t help me!). Thirdly, the only way you can change the sound is via a removable bass port and a passive treble roll-off button. The AxeTrak needs some decent EQ-ing before it stops sounding honky, and you just can’t get much tonal variety out of it the way you could if you were to move a mic around to find the sweet spot for that particular amp, song or solo. So although it’s served me well, it has some limitations and if you’re considering an AxeTrak I would recommend that you look at more recent models than mine.

The Jet City ISO12, by contrast, offers a few things that the AxeTrak just can’t deliver. First of all, it features a full 12 inch speaker, by Eminence, no less. The speaker is custom-made by Eminence for Jet City, and it handles 100 watts RMS. The ability to have a full-sized speaker means there’s more area for the microphone to sense, and therefore more tonal variation to be achieved by moving the mic to different positions or angles.

And then there’s the mic: there isn’t one. The ISO12 instead gives you a gooseneck mic stand and an internally-attached XLR cable, so you can use your own mic – or, if you’re particularly adventurous, various different microphones. You can achieve a good degree of movement inside the cabinet, and whether you like your mic placed right up against the speaker, or back a few inches for a little more sonic depth, or at an angle to achieve unusual phase-cancelled sounds and what have you, the ISO12 will accommodate you.

The ISO12 cabinet is made of void-free plywood, and the only inputs and outputs are a 16 ohm 1/4″ amp input and an XLR microphone output. Part of the front of the cabinet unlatches and opens outwards so you can access the mic (and see the cool soundproof padding), and there are a couple of rubber handles on the side. The whole unit is super-simple.

I plugged my Marshall DSL50 into the ISO12, and attached my Shure SM57 mic. The first thing I noticed was that the length of the gooseneck is such that you have pretty much no choice but to rest the mic directly against the speaker itself if you want to set the mic front-on. If you’re going for an off-axis sound you have a little extra room to play with, but it’s still pretty close. If Jet City’s reading this, I’d love to see a future update or perhaps an aftermarket kit that allows you to set the mic a little bit further back for a little bit of ambience. Having said that, the ISO12 sounds great. The speaker displays that characteristic Eminence crunch that I’m so fond of in their V12, a speaker I’ve been using for about 15 years now. The ISO12 sounds nice and crisp on clean and lightly overdriven tones, and it positively kicks ass on high gain stuff. The ISO12 is also free of the ‘boxy’ sound that plagues the AxeTrak and which I’m used to having to remove with EQ. It just sounds great straight out of the box. When you seal the cabinet up and crank the amp it’s still quite loud, but probably not loud enough to piss off your neighbours. Ultimately it’s a much more life-like sound than my beat up old AxeTrak.

The ISO12 is a no-brainer for those wanting to record a roaring tube amp without getting evicted, or who just want tighter control over their live sound. You could quite easily plug in your favourite mic, take the ISO12 and an amp head to a gig, and never be at the mercy of an unsympathetic soundie again. Jet City has really got it right by providing a high-quality full-size speaker and leaving the micing up to the artist. It can’t beat the AxeTrak on portability and plug-in-and-go-ness – and once you find a preamp or EQ setting that works well with the AxeTrak you can get some really consistent results – but for those who are into using their own mic and who have the space at home or on stage for a larger unit, the ISO12 is a very handy option indeed.