Trumpet sound absorbing box-Acoustics Forum-Acoustic Fields Forum

I play jazz trumpet. I have young kids who want to sleep when I want to play. I want to play in my house, not outside or in my van.
But I have an advantage – a house with 2 foot thick walls & a small storage room in which I could play. So have built set of 2 doors with layers of plasterboard/wood/MVL/greenglue (each weighing 150lb).
Now enough sound is absorbed that its just quiet enough outside the room whenI’m inside playing.
But what I hadn’t thought about is how loud it is in the room itself – with lots of sound reflections – and that’s before I even think about playing backing track with rhythm section, or clear out the junk in the room which must be absorbing some sound,.
So I’m now thinking I need to build a sound absorbing box which I can point the end of the trumpet into while I’m playing.
And I figured the DIY bass box might be a place to start
Dennis – what do you think?