Where did DINa come from ? Looking at the SRA diagrams, I don't think I would use this configuration with hypers (maybe cards)... DINa gives a +/-35 SRA, which is typical for most of the venues I record in, but 120° puts you a good bit into the reverberation limit of the theory. Using hypers in a recording situation with a SRA of +/-35 I would choose 32cm x 80° ... Not only would this config give you a more stable image, it would also limit more chatter and reflections from the sides.... my $0.02
I just ordered a ⅝-27 die and stock to make my own rods, so I can have a selection of mount sizes. I'll slide the rods in a shock/isolation mount and attach my rode swivel mounts. This would be similar to the kwon bar setup but much cheaper and I can make any size I would ever need....
I am going to make bars for every SRA angle from +/-30° -> +/-60° chosing the most ideal point on the graph.
Here are the options I will have...
notes:
- the rode swivel mounts give 17cm without a extention bar....
- I can't make a bar larger than 22cm becasue it wont fit in my bag, so I am limited to 37cm distance....
- The threads are 1cm, so 2cm per bar of threads...
- To limit the amount of bars I need to carry, slight compromise is made on the hyper graph...
Cards:
SRA+/-30° = 37cm X 110° = 22cm bar
SRA+/-40° = 32cm X 85° = 17cm bar
SRA+/-50° = 23cm x 80° = 8cm bar
SRA+/-60° = 17cm x 80° = No Bar
Hypers:
SRA+/-30° = 37cm X 90° = 22cm bar
SRA+/-40° = 32cm X 60° = 17cm bar
SRA+/-50° = 23cm x 60° = 8cm bar
SRA+/-60° = 17cm x 50° = No Bar
So, all I need to cover a 60° -> 120° SRA without reaching the angular distortion or reverberation limits is 3 extention bars!