The 70s was a time when there were a lot of small speaker manufacturers, and many brands made specifically for particular stores as inexpensive store brands. Filip may have been sold at certain stores, or who knows. It's not surprising to see obscure brands from that era, happens all the time. Since they are 'ok' speakers but not high end, they never gained a following in the modern collector community. Probably not much published info about them, compared to, say, Altec's data sheets on their speakers and drivers. They were not heavily marketed nationally. They predate the internet. Taken together it is not surprising there is 'nothing on the web.'
Except now there is.