10” MTM design help

When mains noise exists, it is usually introduced to the equipment via electromagnetic radiation, long cable runs, low signal levels, circuit layout or electrically through such things as power supplies or grounding methods.
 
Any frequency below the floor/ceiling mode (8 ft = ~70.5 Hz) is normally a room mode and the other is likely due to the huge dustcap since it shows up on the factory measurement.

Drat! :cuss: :headbash: Caught out again by not being able to see the 'hidden' messages till after posting, though having never had the power problem to even consider it in these modern times...........
 
Back in the day, i would always get buzzing hooking up from the tv to a receiver using rca (analog) outputs.
I assumed different video audio grounding stuff....................

My kid runs his ps4 to tv (hdmi) then tv to receiver (hdmi or coax).
From the ps4, we couldn't run hdmi to tv and coax to receiver.
don't know why........
 
I’m kindly surprised it worked as well as it did!
according to the eminence factory measurement for the stock delta 10b has the impedence spike right at 60hz, that might have something to do with it also?

They use a 2’x2’ baffle (according to the footnotes) so that would be the bass slope difference.
 

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It was the only way I had to get the rew from the computer usb to the receiver………like i said, first time i ever used it.

My good receiver has a usb/dac input but isn‘t hooked up at the moment
Not having actually tried REW yet* ... could you just hook the sound card or headphone output to the receiver?

If not, I was going to say I have this cheap USB DAC with optical & S/PDIF out hooked to my Raspberry Pi right now, it might not be "bit perfect / jitter-free" but it would put the DAC quality over on the amp side. ... But strangely, I can't seem to find an equivalent right now.
https://www.amazon.com/gp/product/B00FEDHHKE/

On the other hand, while I am not sure how much the quality matters, but in light of the Vizio adapter, I have also used this (although from NewEgg):
https://www.amazon.com/Syba-external-Adapter-Windows-C-Media/dp/B001MSS6CS/

*I don't have a microphone yet but I did get a Dayton Audio DATV3 for my birthday, that I haven't had time to mess with. I read it is actually just a modified sound card, I wonder if that could be used for REW output as well? Because that would greatly help, the wife has a Window's desktop, but all I have are old Chromebooks I put Ubuntu on.

And if that works, these also may work.
https://www.amazon.com/dp/B071HJ98Q6/
https://www.amazon.com/dp/B00XM883BK/
 
Hah, :cuss: :headbash: (I learned that from GM!)

Thanks CF, I’m using a Mac mini and until you just prompted me to look closer i didn’t realize it had a headphone jack!
i’m sure glad you mentioned it because I probably never would have seen the hole with a tiny headphone emblem. I even have the proper adapter cable to rca…….i’ll remeasure tomorrow and see if it makes a difference. 😎
 
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Ok, looks like a little of both, noise from the vizeo and baffle step combined.

red is original measurement yesterday through the vizeo tv

blue (next line up from bottom) is same setup directly on floor but wired from headphone out mac mini direct to receiver

green (top) is in a 2’ baffle with headphone out and improved mic stand

issue @ 60hz is still there but much improved…….things got a little wonky in the midrange with the baffle though?

edit…… could the midrange disturbance be from vibration due to the stick being tied into baffle?

edit 2…… to answer the last question, i removed the stand mount from the baffle and measured again getting exactly the same result.
 

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after trying to figure out things a little more, I matched levels better and smoothed to 1/12.......looks a little better?
oh, and figured out how to screenshot the Mac mini !

edit…….all criticisms are welcome, if anyone sees anything i’m doing wrong with this please speak up because fumbling in the dark doesn’t even begin to describe whats going on here! 😉
 

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Thanks Allen, hopefully my struggles will be beneficial for others in my position such as 6xS7

Yes, gating and phase are the next things to fine tune……..actually the impulse response didn’t show a whole lot but,I reckon once playtime is over and it comes down to it i’ll have to dial in a consistent measurement protocol.
Outdoor measure is going to be difficult here as its always quite windy……..the neighbor has a 40x80x25 barn for his giant motor coach he said i could use if need be.
And to tell you the truth I’m actually more interested in the room involvement @ LP anyhow but one must learn how to do something the right way to have a good baseline before veering off the path! I think its referred to as crawling before walking 😎
 
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