Weird C-note Problem

[badspeakerdesigner]

I shared this in the C-note review thread but figured that might just get lost in the noise and this subforum would offer me a better chance of figuring things out.

You can see my issues laid out here. Easier to link to the post than type it all out agian. I have shared this info on several other forums and haven't really gotten any closer to a resolution and becoming quite discouraged.

Parts Express DIY C-Note Speaker Review

Curious how you did the flush modification? Trim the tweeter diffuser but then made another round cut into the existing face board with a router? I followed ChrisP's suggestion from earlier in the thread: I mounted the tweeter and cut the cabinet and waveguide together in a single pass.

audiosciencereview.com

 

[Rick Sykora]

Checking the other thread, agree with @mcdn. Please answer his questions here and will try to help.

For reference, you can see my C-Note measurements in the build thread. They are a more realistic target for you than trying to reproduce Amir’s Klippel ones.

 

[badspeakerdesigner]

Setup is EMM6, speakers up on a ladder about 7-8ft high, interface is motu m4.

I don't expect to match klippel or PE's results, but my results are so far off from what they should be that it doesn't make sense. Not to mention when placed side by side with the Kali, the c-notes will tear your head off with treble and do not sound right at all. I would agree that the kali exhibit a HF rise that isn't in say EAC's data, but it tracks flat, while the c-notes shoot for the sky.

If you're bored you can scan over this series of measurements, I put the xover together piece by piece and measured. .mdat and mic cal can be found here.

https://drive.google.com/file/d/1kg0O3cXV8qkI5IKsI3tRA0zQ_b9orS34/view?usp=share_link

 

[Rick Sykora]

Have plenty else to do, but whether me or someone else...

Have you read this? https://www.audiosciencereview.com/...ents-spinoramas-with-rew-and-vituixcad.21860/

You can skip the off-axis aspects, but until you establish that you are correctly set up to measure, your measurements cannot be relied upon.

 

[mcdn]

Repeating my questions from the other thread:

What’s the physical measurement setup (audio interface, mic distance and position, location of speaker in room, size of room)?

And what’s the REW setup - gating, windowing, etc?

 

[badspeakerdesigner]

There are mdat files there so the window and gating are whatever you want them to be.

Setup is outside, 8ft off ground on a ladder, mic is 1meter away, interface is motu m4.

PE is gonna be contacting me again, which is a huge relief based on how unhelpful most forums have been. This forum seems kinda of annoying as my posts need moderator approval? Think I'll pass on further correspondence here.

 

[AdamG]

This forum seems kinda of annoying as my posts need moderator approval?

A few more posts and that will end. It’s just a standard spam prevention protocol for new members. Understand that it is annoying. Hang in there.

 

[Rick Sykora]

There are mdat files there so the window and gating are whatever you want them to be.

Setup is outside, 8ft off ground on a ladder, mic is 1meter away, interface is motu m4.

PE is gonna be contacting me again, which is a huge relief based on how unhelpful most forums have been. This forum seems kinda of annoying as my posts need moderator approval? Think I'll pass on further correspondence here.

Hope that PE support helps.

Many of the members here are experienced problem solvers, but as mentioned earlier, we cannot help without good information. If you are not prepared answer each of @mcdn simple questions, then there is not much we can do for you. Take some time for those willing to spend time helping you and am confident you will get better results.

 

[D!sco]

Is there any chance you have a treble knob out of whack on an amp, preamp or EQ somewhere? I couldn't find the bass in my music for a few days when somebody bumped into the tone control. If the speakers and mic are accurate it has to be the environment or the amp. Maybe you're in the "sweet spot"?

 

[mcdn]

@badspeakerdesigner in your mdat file the in-cabinet tweeter response without any crossover parts looks absolutely fine, although the resonance peak at Fs is a bit larger than the raw driver spec. Then the other graphs start out looking like you'd expect given the notes on xo components against them, before going off the rails at measurements 7 and 8 (I think so based on eyeballing anyway, haven't stuck it in a simulator to check). Have you tried measuring the crossover electrical response with a 4ohm resistor in place of the tweeter to verify nothing's up with that?

 

[badspeakerdesigner]

I never got a reply from PE, but I did find something interesting, I shared it in the review thread but that seems a bit dead at the moment. Someone here shared some info about alterations in FR based on class D amps without post filter feedback (I'm not sure what that is). Anyway I grabbed a class a/b from a friend and basically found that the A07 amp gave me the HF rise while the class A/B did not have it. The differences were repeatable and definitely audible. Had to do the measurements inside but that should be fine for a comparison like this.

Green is A07. Orange is audiosource amp 100.