此外，韻圖雖然可以將字音嘅結構分析到「音位」嘅程度，但佢對音位嘅描述是籠統模糊嘅，缺乏科學抽象性。譬如，毋計特例，一轉之內韻尾相同或發音部位一致（入聲），但具體哪一轉係咩韻尾韻圖本身並無表示出來，仲需要讀圖者自己來歸納。又如，不計特例，同轉同等有相同嘅韻腹（韻母中的主要元音），但這個元音具體如何，韻圖同樣無法表示出來，切韻音的韻腹，依王力擬音有12個音位，依李榮擬音有11個音位，而《韻鏡》《七音略》等韻圖卻只有四個等，韻圖對韻腹音位分析的模糊程度可想而知。
In addition, although the rhyme diagram can analyze the structure of the sound of words to the level of "phoneme", his description of phonemes is general and vague, and lacks scientific abstraction. For example, regardless of special cases, the rhyme is the same or the pronunciation part is the same (into the voice) within a turn, but the specific turn is what rhyme and the final rhyme itself is not indicated, and the reader needs to summarize it himself. Another example, regardless of the special case, the same turn has the same rhyme (the main vowel in the vowel), but how specific is this vowel, the rhyme diagram can not be represented, the rhyme belly of the cut rhyme, according to Wang Li Foley has 12 phonemes, according to Li Rong Foley has 11 phonemes, and "Rhyme Mirror" and "Seven Syllables" and other rhyme charts have only four etc., the degree of ambiguity of the rhyme diagram on the analysis of the rhyme phoneme can be imagined.