advice please on cleaning up a midrange issue

[ecwl]

I did 3 new measurements with REW this evening... L speaker, R speaker and L+R together. These are the spectrogram captures. Are these helpful? I did new measurements because I've changed a couple of things since then?
If you don't mind me asking, does anything obvious jump out.

The measurement looks great. Probably the best I’ve seen of people who are willing to post their measurements online.

Now I’m wondering… How long have you had the Denafrips Pontus II? Sometimes people notice what you describe in some R2R DACs in NOS mode.

Another possibility you’ve already mentioned. Sometimes having sonicorbiter directly connected to the Denafrips might lead to more jitter and more noise so having a Roon-ready streamer might improve that.

Otherwise, I’m not sure what’s causing the issue you’re noticing.

 

[GeoffR]

Amazing, thanks for looking at it. I've had the pontus for a while (couple of years) and was running roon through my laptop directly into it via usb. I had read far too many times that laptops can cause noise issues that, along with wanting to get my cd's into roon and the inconvenience factor of using my laptop, prompted me to get the i5 as dedicated server. The quality of the sound definitely went up.

I think what prompted this thread was adding a couple more acoustic panels to my room and repositioning my speakers a touch, which locked in the clarity even further.

It did seem though that every time something improved, something else was exposed. First, it lacked some bass, but the pontus upgrade improved that. That's when i started to notice the fuzziness in that midrange zone I mentioned.

I did post to this specific thread (Digital Audio), because my preconceived idea going in was whether it was a hardware issue. You guys have introduced some very interesting ideas and I've been happily exploring them, but now I'm wondering as well...

Have I got it to the point that small details are being exposed, as well as maybe some less than perfect recordings sound harsher, than I had noticed before? That might bring me back to the idea that you mentioned... maybe a streamer is required. The guys at Small Green Computer HIGHLY suggested I get one when I purchased the i5, but budget didn't allow for it, and quite frankly I was very pleased with the improvements the i5 brought initially.

On one hand I'm pleased that it doesn't seem to be a damage situation, but on the other hand I can't unhear some of the fuzziness that's present in some recordings at certain frequencies.

 

[Ron Resnick]

Welcome to WBF, Geoff!

 

[Folsom]

It looks ugly in that midrange. The only fix I see is changing the speakers internally or entirely. Everything else could help but I would be ashamed if I released speakers with that. There is a company that does free crossover design if you ship a speaker and buy parts, but not everyone is into that.

 

[sbnx]

The company that does that is GR Research

 

[sbnx]

View attachment 141220

It looks ugly in that midrange. The only fix I see is changing the speakers internally or entirely. Everything else could help but I would be ashamed if I released speakers with that. There is a company that does free crossover design if you ship a speaker and buy parts, but not everyone is into that.

those are side panel resonances. GR Research sells a product called no rez that is peel and stick. You cut it into pieces tgat fit through the driver holes and coat the inside of the cabinet with it. Bery east to do.

No Rez (Sheets) | GR-Research

gr-research.com

 

[ecwl]

@Folsom might be right. Maybe OP optimized the system so much that now you’re just hearing the inherit weaknesses of the speakers or another equipment in the signal chain.

Hard to know without listening to it in person. But also hard to advise whether replacing speakers is the best option. It probably is but just hard to say for sure.

 

[DasguteOhr]

View attachment 141220

It looks ugly in that midrange. The only fix I see is changing the speakers internally or entirely. Everything else could help but I would be ashamed if I released speakers with that. There is a company that does free crossover design if you ship a speaker and buy parts, but not everyone is into that.

These are resonances in the housing. Removing the bass driver and adding some cross braces in the speaker housing could help. The only thing that helps is to try and then measure. Tinkering with the xover doesn't help much. Perhaps something has come loose internally or the insulation is no longer where it should be.

 

[Folsom]

That midrange may simply playing way out of the zone it should be playing. Something is up, that kind of buzzing is reflective of another issue, clearly.

Cross braces are not always a good solution. Damping maybe. I just don't see how you get that kind of excitement on a panel without something obviously wrong from a design perspective.

 

[analogsa]

That Atoll amp... not good at all imho.

 

[GeoffR]

That Atoll amp... not good at all imho.

Thanks for your concise review! And, yes you are absolutely right, but maybe not as initially intended??

I just want to update where I'm at with this. It definitely sent me down a rabbit hole to figure this out, so I'll put this thread to rest for now with what I have discovered...

From the info I provided, it did seem like the obvious answer was a problem with the speakers. But also, there was still a question hanging over the amp. So, I took some time to start switching out components from my AV setup in the living room. While it's pretty basic, I did have a Marantz AV receiver I could sub in lieu of the Atoll. Interestingly the mids seemed clearer, but because this is a completely different sounding unit and everything sounded a little less defined. But also this is where I think I found my problem...

When I put my Atoll back in place and plugged it in, I noticed the socket into the amp was quite wiggly/loose. I Googled that and it suggested some "play" is normal, but this seemed excessive to me. Then, when I switched on the power button on the back of the unit I heard a faint buzzing sound from the amp itself (not the speakers) that disappeared in a couple of seconds. That concerned me. I switched if off and took a look at the chord going into the socket. It was also a bit loose. I pushed it in as firm as I could, switched it back on and while there was no buzzing immediately, it did again start after a few seconds. It seems that the weight of the power chord (Shunyata Venom, so a bit heavier than stock but nothing crazy), was tilting down and seeming to come loose. I found another power chord (probably the original stock chord) and sure enough it gripped tighter in the socket. I propped it up with a piece of foam so that it went straight in with no sag, and turned it on. Zero buzz. I went ahead and turned the amp onto full operation, played some music, and... clean!

I'm still not discounting some issues with my speakers, but for now the improvement has me enjoying this system again. I've called my dealer because I want to have the amp looked at to ensure the socket is performing as normal, and also to see if any of that 'buzzing' has damaged anything on the amps internals. It's going in after the holidays for inspection.

Sincerely, thank you. Everyone's input helped me get this far.