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Center channel distortion. Need help troubleshooting.


New Member
Jan 28, 2022
I have a 5.1 setup with Dali Helicon mk1s; 2x 400, c200, 2xw200, svs pc13ultra being driven by a Denon AVR-4308ci.

During scenes with like rockets or jet engines it sounds like I'm getting some distortion in the center channel, and I can't really narrow it down. It's not too bad and I've thought it might be worse with DTS-MA or just certain source materials, but I can't ignore it anymore. I don't listen at reference levels and I have a fairly small room for all of the gear in there. I'm wanting to build out my room and do a few upgrades so it's finally time I figure out my HT audio setup.

I bought the Dali's mainly for 2ch and just added the rest to serve double duty with HT. I love listening to music with them but the whole ht experience has never been the best. I actually have the surrounds in a closet collecting dust. If I can't figure this out I'm going to sell the center channel and surrounds and buy a cheaper(maybe kef q750) setup just for home theater and keep the 400s for 2ch.

One of my thoughts was that I'm pushing the Denon too hard since the Helicons are 4ohm nominal. I was actually about to buy another amp to see if that would help when I found a bunch of articles talking about the AVTech testing down to 1ohm with the Denon. With that likely not being the problem, I would guess the center channel tweeter? I don't want to swap it out, unless I know it's gone. I don't even know if Dali would give me another one.

How can I narrow this down? I haven't heard this with music, and it seems to distort at even fairly low volumes during these scenes.


Grand Contributor
Forum Donor
Dec 9, 2019
Frequency sweep the suspect speaker with this. If there is a issue it will most likely show up at specific frequencies.
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