Hi, I am no audio expert and have very limited knowledge on the speaker systems. I bought an Onkyo TX-SR875 AV Receiver with a pair of KEF iQ9 fronts about 6 months ago. I am very happy with both of them. Now I want to upgrade the system to 5.1. there wouldnt be any problems if I had enough budget for the upgrade and I would go for KEF again for sub, center and surround. But the fact is I have limited budget and can not afford at this time. I would like to ask if it is technically possible to upgrade the system with more affordable speakers like wharfdale ? I have heard KEFs are 8 ohms and wharfdales 6 ohms. Does this create any problem? If it is possible, does it make sense to go for them? I am not a big big fan of home theather and I will use the system occasionally for DVD (3-4 times a month) and will mostly use for TV which I think will not add any value.