audience au24

how can i try a pair of au 24 interconnects before i buy?
I don't think Audience sells direct. I bought some Au 24s and Like them but that is not going to help you. What might is a dealers who may be able to let you home demo a used pair from the shop.
In addition, if you can afford more, buy two different brands that you are interested in, play both and sell one. Then buy another to compare to the one you kept first. Synergy may surprise you and as you sell off your last pair, your cost is still about the same.
The Cable Company loans out cables to try and they are reputable, but i agree with the others, buy and try, you won't lose out.
Cable Company(1-800-FAT-WYRE) as suggested will let you borrow any of the interconnects they cary, but at a 5% non-refundable deposit. This deposit is counted towards your future purchase of anything from them. I've used them in the past and had nothing but great experience. They are very helpful.

In the same price range, the AZ Matrix RefII could also be recommended(if you like a bit more dynamics). So if you're borrowing from cable company, don't forget to grab few different ICs, including the Acoustic Zen.