A universal language can express anything that can be expressed in language. If qualia are outside the realm of language, that wouldn't make English less universal.
You may say dolphins use a language, and then feel qualia in response. Similarly, we can imagine a human who is genetically engineered for his skin to pinch when he hears certain sounds, so that he would feel the pinching quale. I think in neither case should triggering hardware features by sound be considered language. A nice example is "clap on" devices -- surely that's not language.
This is sort of like the difference between playing a text game like Zork or a 3D MMO like World of Warcraft. English only descriptions leave the details up to your imagination. 3d graphic imagery communicates the actual picture.
Further, really detailed and well written prose can describe 3d scenes -- and help the reader visualize them -- better than everyday photographs, 3d computers renderings, what dolphins have, etc... There is no limit to how much detail prose can include.
As a practical matter, we do not use English to its full capacity, and it's inefficient for some things, but still it is universal.
Dolphins use such high-pitched and information dense communication that it's highly possible they are communicating raw data that is directly converted into a 3d map or image by the receiving dolphin's brain. Listen to a dolphin's speech, then think of what a 56k modem sounds like... not too far off huh? Now imagine that dolphins could communicate actual 3d maps or sonographic images using sound, rather than just describe them.