If I'm not mistaken, CAT-5 wires have a copper diameter of 0.5mm. That's about 2 hundredths of an inch. Way too small for loudspeakers. Suggest you try to do it yourself: Attach VERY securely your speaker wire to the CAT5 by separating the individual strands and twisting them around each leg of the speaker wire. Then bind the whole mess with tightly wound electrical tape. They key is to try to keep this strong but without increasing too much the diameter. Grease up the cable with some vaseline or something and then start pulling it through. It might take a few sharp jerks to get it going, and it helps to have someone else feeding the sppeaker wire (and applying vaseline occasionally) as you pull. If there are not too many sharp bends in the cable run you might be lucky. If it is too difficult, you will probably separate the cat5 from the speaker wire, and in that case you will have to start from scratch with one of those plastic feeders for running cable (you will find at any hardware store). Even then, you might not be successful. But CAT-5 is just WAY to small for speakers.