Fedor K.

I’m pretty new to HT audio. I recently purchased a denon 4500 and 280FAs as fronts. After playing music with the volume all the way up for a few minutes the audio begins sounding unclear or slightly distorted. Is this because of speakers or receiver? I’m also very interested in knowing if I could add 2 more 280s and an amp, and how to hook this all up together with the receiver. Thank you!!