Bobbsy
Boring Old Git
Trying some EQ adjustment is a good idea...it might be that cutting a bit of HF is all you need. The only trouble is, mixers vary greatly on how accurate you can be with your adjustments.
Buying a "darn good XLR cable" is also a very good idea--but not for the reasons suggested. Except for something actually wired incorrectly or something, an expensive XLR cable is not going to sound even slightly different from a cheap one. The differences come in with the longevity of the connectors (cheap ones can break quickly) and the ease of handling/coiling. Cheap ones tend to be stiffer and far more prone to tangles and kinks that can damage the wires inside. So...if you can't make your own (and that's my recommendation--you'll be amazed how easy it is) buy from a reputable professional company, not a rip off audiophile merchant.
Buying a "darn good XLR cable" is also a very good idea--but not for the reasons suggested. Except for something actually wired incorrectly or something, an expensive XLR cable is not going to sound even slightly different from a cheap one. The differences come in with the longevity of the connectors (cheap ones can break quickly) and the ease of handling/coiling. Cheap ones tend to be stiffer and far more prone to tangles and kinks that can damage the wires inside. So...if you can't make your own (and that's my recommendation--you'll be amazed how easy it is) buy from a reputable professional company, not a rip off audiophile merchant.