Isolation Cab Project for Recordings

My Latest Guitar-Recording Tool

We all want to record our amps cranked up a bit because that’s when they sound best. However, it’s not always practical or convenient to turn up loud in a project studio!

There are various solutions to the issue of satisfactorily recording electric guitar, one of them being the ISO cab (isolation cabinet) or ISO box. An ISO cab is a speaker cabinet that houses the speaker inside a soundproof enclosure. An ISO box is basically a soundproof box with a normal speaker cabinet (or combo amp) inside. Both aim to achieve the same thing. Have the amp loud and the box isolates the noise from the outside world.

I don’t need to record at ear-bleeding levels to get the best sound of my amp because I use a Quilter Tone Block and that thing sounds great at low volumes too. However, to non-guitar geeks in my home (namely my wife and daughter), what I consider to be a very modest volume is, in their words “TOO LOUD!”, so my ISO box was not so challenging to build because the soundproofing required is not that much, just enough to make it quieter than “a little bit too loud for everyone else”.

This was a simple project to undertake using only materials I already had to hand to keep cost down. I put together the frame to form the front panel, making sure it was a tight fit into the opening of the front of my workstation enclosure. Then I filled the space in the frame with rock wool, covered in an old blanket.

I made a very ugly, messy looking speaker cabinet (open back) from scraps of MDF and chip-board. I already had the speaker baffle made from last year when I tried putting my 10″ Tone Tubby in my 1×12 cab (I preferred the 12″ speaker). I love the Tone Tubby for recording and a 1×10 cab is as big as I’ll fit in the space available, so that’s worked out perfectly.

Inside the enclosure I put rock wool panels that I cut to size, backed with some cardboard and wrapped in blankets. I made them fit, so that the panels all help to hold each other in place. I also put a panel on the bottom under the cab to decouple it from the enclosure. The box is now lined with rock wool on the bottom, sides and back, a rolled up rug at the top with a little hard surface remaining (it sounded better than covered) and when the front panel is in place, there is insulation in front of the cab too. There is just enough room for the mic to fit in front at the right angle (it took a long time tweaking the position to find the nicest overall sound).

The mic is attached to the top panel of the enclosure and hangs down in front of the speaker cab, so it’s totally decoupled from any surface that is common to the cab.

It works very well indeed and I’m really happy with it. It has cut down the volume massively and sounds great through my monitors.


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