Here is what is mentioned in http://www.customs.gov.au/site/page4443.asp#items
<i>Currency
There is no limit to the amount of currency you can bring in or out of Australia. However, you must declare amounts of A$10,000 or more in Australian currency or foreign equivalent. You must disclose any promissory notes, travellers’ cheques, personal cheques, money orders, postal orders or other bearer negotiable instruments, regardless of value, if requested by a Customs and Border Protection officer or police officer.</i>
But if I were you guys, para iwas aberya na din either sa AU immigration or Philippine immigration, most specially, try to bring na lang below 10K. Think of other ways on how you can send your money to AU like bank transfer, ATM withdrawal, etc. It may entail cost such as bank fees but saves you the pain of going through possible interrogations.