Pruning my shrubs...now?

i have got three shrubs which are about five or six years old now...one is a sambucus nigra black lace, one a red robin (think that's what it is called) and one...well I'm not sure what it is but the flowers in spring are white and smell gorgeous! As I only have a small garden, I wanted to perhaps cut them right down this year to give my other perennials a chance of getting more light and becoming more established. They struggled last year and were clearly desperately seeking out the light. My question is, can I prune them now and if so, can I cut them down to almost ground level? I appreciate that they won't flower if I cut them right back, it's just that they are starting to show signs of growing now so I thought it best to cut them back before they do! Thanks...

 

The Sambucus can be cut down as hard as you like, it will probably make a better shape then, arching from ground level .
The Photinia looks more like P.davidiana than Red Robin can be pruned to shape rather than a hard prune.
The spring flowering shrub, if it is a Philadelphus which is late spring flowering, can be pruned hard and will recover but will not flower for a couple of years. I would tend to prune that after it has flowered cutting out the older branches and leaving the younger vertical growths

 

Thanks so much...I will go with what you suggest :-)) here is another pic of the unknown shrub in leaf...I don't have one with it in flower...

 

that one looks like Philadelphus coronarius 'Aureus'

 

You are indeed correct....I cut it back and found the label ha ha