loudspeaker in box (plus feedback)

[SheHadTheJack]

tried posting this post earlier without succes, so i might have made a repost.

Anyway. I live in a paper thin appartement in a 4 floor complex, and i wish to record my guitar loud and with feedback. Thats not possible because of my neighbours. I was thinking of making an isolated box with a loudspeaker in it (i have a musicman amplifier and a loudspeaker, so the amplifier would be outside the box). That way i can turn up the volume on the amplifier.
Next step would be to make a loop in the amplifier with a microphone inside the box.

What do you think. Could it be done? Will it work? Have you tried this? Do you know where to find a recipe for an isolated box?

Any comments appreciated (allmost )
Thanks
Carsten

[tarnationsauce2]

Well, the feedback is caused by an amplifier oscillation. In order to do that it needs a high gain feedback loop.
Usually that is in the form of the speaker's reaction with the pickups in the guitar.
Simply put, your guitar will have to be in the box too.
OR... (this is unorthodox)
You could wire a pickup inside the box, and parallel it to your guitar's pickup.
But this could have a couple problems.
1. The external pickup will load down your guitar's pickups... your guitar will not have as much output as it should.
2. The feedback will be pretty boring as it won't have the dynamics like a guitar feeding back. Partially because the pickup will be in a static position, causing the feedback to oscillate at a fixed frequency (dependant on how far away the pickup is from the speaker). Also that pickup will really want to feedback even while you're playing since it isn't attached to the guitar and doesn't have the strings to overcome the feedback by overpowering the feedback.

[pandamonk]

I did a plan for an iso box for someone else. Check it out here