Spanish coats-of-arms rarely include helmets on top of them - that is more an English thing?
Moreover the helmet in your picture looks to me like that of a duke, marquessate, earl, viscount or baron (in English heraldry)?
They should be composed of silver or polished steel, with five gold bars, and lined with crimson. According to some authorities they should be placed neither affronty nor in profile, but between those positions.
Yours is lined with green - with makes me think that maybe it was re-painted at some time?
Also, some of the colours are wrong (again from an English Heraldry point-of-view). White/silver should almost never be next to yellow/gold?
I looked at a catalogue of Spanish Arms, and while I did find 8 (or so!) arms per saltire, none of them were like yours in the 1st quarter.