How to design acoustic synth pad?

How do synth pads work?

How are their sounds generated?

I would like to design acoustic synth pads. Where do I start?

I would like to design them so that they have a frequency response
approximately from 800 Hz to 90,000 Hz and a dynamic range of about
210 dB.

I would like to make 8 pads:

1. New Age
2. Warm
3. Polysynth
4. Choir
5. Bowed
6. Metallic
7. Halo
8. Sweep

These instruments are already on keyboards. I would like to make their
acoustic equivalents.

 

90,000 Hz?? 90 kHz??!! You do know that humans can only hear upto 20 kHz
at the best of times.

 

You're half way there if you can get an orchestra to play in a parking
garage. Add a couple dozen harp players in a canyon with the Vienna Boys
Choir singing in a meadow and you're all set.

Micing it all might be tough.

Pads really need a lot of reverb, delay and layering to fill up and spread
out.

dtk