For those of you with experience regarding isolation boxes

The answer to your question(s), in short, is no. It won't work. Whatever box you build has to have a lot of mass, and be airtight. I built a room like this...it wasn't cheap. It functions as you describe though. I can crank any of my amps, anytime day or night!

In my opinion, the best thing would be to get a palmer (or POD, fractal, etc.) for when your wife is around.

 

ear plugs for the wife!

 

You can build a very quiet iso box with good sound quality but not the way you have specified it.

To make it quiet you'll need mass and airtight construction. I built my isocab with two 3/4" MDF airtight sealed boxes, one inside the other, separated by 1" of air space. I glued and caulked the joints, sealed with rubber weatherstripping and compresion latches, and installed sealed jack panels to pass speaker and mic connections through.

To make it sound good you need volume (ie size) and you need to kill reflections. The bigger the box the better it will sound. Mine is about 37" by 30" x 33" or so. Damp the reflections by covering the inside of the box with oc703 or acoustic foam.

 

1x12 would be helpful. 3/4" MDF is heavy...double layers of 3/4" MDF would be very heavy.

I started to build a box like that years ago 40"L x 30"w x 36" tall (or something like that). I stopped working on it when I realized it was going to weigh as much as an upright piano. We didn't even use MDF.

Are you sure you wouldn't want to try a Palmer load box first?

 

Yes, I forgot to mention I keep a 1x12 cab in mine.

Mine sits on a concrete basement floor. I've never even contemplated what it might weigh!

A palmer PDI-03 is definitely another option to try.

 

I built some panels out of 2 inch rockwool with 1/4" ply backing .. covered in fabric.. made mine for live use and with a 50 watt marshall full tilt into a 4x12 it is really quiet.. suprisingly quiet actually. Rockwool sucks the sound up like a sponge does water

 

You could go one of two routes. Either one is an excellent recording solution. I got this tip from Adam Stark and it works better than an iso box IMO.

This my first recommendation try Floating your iso box. It may be that the actual volume of leaving the iso box is not the problem more likey if your wife is right above its the vibration being produced from the llow frequencies. If you get 1 inch dense rubber. Not uncommon for sound proffing recording studios you simply place it under the iso box. This rubeer would absorb 90% percent of the vibration and possibly even increase performane of the iso.

Option 2 Adams idea: Badger into palmer 3 out to line 6 for use only as cab simulator. Direct into board monitors. I use a dual demeter iso cab and honestly Adams solution sounds more realistic at least I thought so after recording using both concepts.