Muffled vocals

For vocal reproduction quality is 99% is speaker itself'
You can try to change wires , room correction , source ,
etc but this is waste of time

Just had an ex industry friend help me set up a pair of speakers yesterday. They are ported, 3 driver floor standers in a large room. We started them close to the wall (14” away) put down some blue tape, made 1” lines and started moving them forward. We move them about 4” at a time. The speakers had no toe in and we kept moving them more and more forward listening to the same track for 25 seconds. We consistently found the closer to the wall the more the Vocals were muffled. Changed the track, did it again to confirm distance away from the wall. Then we did the toe in, 25 seconds, move, verify.

I’d say zero everything out, get some blue tape and try the above. It helped having a second person for a saniety check and to move speakers while the other listened. Once you get very close then run your room tune.

My source is a bluesound vault 2, MQA files via Tidal feed by blue jeans coax at 192. We could hear a huge difference (bad) when they were too close to the wall for my room and those speakers. Would my system benifit from a difference source or cables, sure, how much, who knows?

Best of luck.

kenscott@
  nobody, but for my point of view , as speaker designer , is very, very  small
no more 5%

@bache
What speakers have you designed?

I would tend to agree with Erik. This seems mostly a room acoustic problem.