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Discussion Starter #1 (Edited)
hello, just put together a pair of c-note speakers


sound ok thus far, however i felt they were really bright


took some measurements and indeed, they are, big rise starting around 6.5k+



thoughts on what could have caused this? i'm pretty sure i followed the directions to a T. and you'll note, identical responses on both. so whatever it is, i messed em up on both :)


EDIT: better REW measurement at 1ft and out in the middle of the room on stools to try and get rid of the nasty room mode. also good to see my L and R channels out of my Topping are matched :). Taken with UMIK1



 

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Do you have C3 connected from tweeter positive to the common negative(in parallel with the tweeter)? I have a feeling a cap when placed like that would pull the top end down as it's shorting the high frequencies.
 

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Discussion Starter #4
Do you have C3 connected from tweeter positive to the common negative(in parallel with the tweeter)? I have a feeling a cap when placed like that would pull the top end down as it's shorting the high frequencies.

yeah, sadly i'm not 100% able to check since i've got the crossovers mounted pretty good in there, and it's really a PITA to get them out


i'd say the only thing different to the picture that i did in real life was orient the caps in such a way that i was able to get C3 L1 and C4 all to touch physically without a wire lead from the C3/L1 to C4 (as indicated by the picture). i'm not aware that that would have an effect on it


i did just put my multimeter on the terminal cap, and read 7ohms, i'm not sure if that is indicative of anything. after connecting two wire leads and reading at the banana clip i got 7.6 (16awg wire, about 6ft). thinking i'm just not making great contact at the cup terminal for a good reading
 

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Discussion Starter #5
just to rule out my laptop, i'm going to grab another speaker to just ensure this isn't something processing or freq limiting on the headphone out. in windows sound settings all enhancements have been turned off, but ya never know
 

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Discussion Starter #7
noted on another forum, found that the topping tp22 has a bit of a rise due to the high resistance, so that certainly brought down some of the issue, but still very noticable


anyone with cnotes able to measure and confirm if this looks normal?


i pulled one of the crossovers, it matches the design spec, i'd really have to start unsoldering items to get measurements


denon avr in green, topping in blue for some reduction



 

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Discussion Starter #9

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The crossover certainly looks correct.

Perhaps there was a small change in the latest batches of that tweeter. I'd try and take a measurement of just the tweeter without the crossover and compare it to the published curves for the ND25FW-4.
 

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Discussion Starter #11
The crossover certainly looks correct.

Perhaps there was a small change in the latest batches of that tweeter. I'd try and take a measurement of just the tweeter without the crossover and compare it to the published curves for the ND25FW-4.

smart man, forgot to completely take out the crossover


- xover measurements -

the below shows a full sweep assembled

sweep with just the mid bass (mb)

sweep with just the tweeter (tw)


- no xover -
just the tweeter


the rise is gone without the xover (some rise can be attributed to the topping tp22, too lazy to drag out the denon which had a reduced rise, but still, keeping it all the same for consistency


now, i'd say perhaps i need to look at the soldering job, but this is producible on 3 individual builds (and i'm sure if i dragged out the 4th, we'd see the same), so maybe they changed the tweet, or maybe i screwed something up, just looking to figure out what that is...


edit, actual measurements :)
 

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not just you. i recently built a set of c notes also and thought they were fairly bright considering the fact that everyone else had been saying they were a great set of speakers that were fairly flat. then again i have mine nearfield on my pc setup.
 

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Discussion Starter #13
not just you. i recently built a set of c notes also and thought they were fairly bright considering the fact that everyone else had been saying they were a great set of speakers that were fairly flat. then again i have mine nearfield on my pc setup.

any way you can measure? i wonder if perhaps they changed something in the tweeter?
 

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Might be worth a call or email to Parts Express to see what they have to say. They are a great company, but sometimes the Quality Control isn't the best on the Chinese parts. My set of Cnotes last year came with a woofer (only one) that had a massively bent frame (and this didn't happen in shipment, it was like that when packaged as the box was perfect). They made it correct, but it was still a QC issue.

IIRC there was an issue with the PE Dayton B652's a couple years back as well as they measured completely different than what they had been even though the same components were being used.

Again, contact them and let them know what you're finding. If they were designed as a "bright" speaker, it'd be a well-known fact at this point.
 

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any way you can measure? i wonder if perhaps they changed something in the tweeter?
i can try to do something tomorrow. ill have to dig up my umik and install the software on this pc and relearn how to use it. i havent messed with it in a while now.
 

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Discussion Starter #16
Might be worth a call or email to Parts Express to see what they have to say. They are a great company, but sometimes the Quality Control isn't the best on the Chinese parts. My set of Cnotes last year came with a woofer (only one) that had a massively bent frame (and this didn't happen in shipment, it was like that when packaged as the box was perfect). They made it correct, but it was still a QC issue.

IIRC there was an issue with the PE Dayton B652's a couple years back as well as they measured completely different than what they had been even though the same components were being used.

Again, contact them and let them know what you're finding. If they were designed as a "bright" speaker, it'd be a well-known fact at this point.

really good thought, i'll give them a call for sure. i 100% had the same experience as you. two busted 5" midranges, completely separate packages. one package damaged, ruined the driver, the other package nothing, driver basket bent to hell.



i'd agree that people are thinking now it's a bright speaker, however ever measurement i've found on the internet is not measurably bright....and i get it, it's 100 bucks, and no one is likely giving a ****, or hell, even has the capacity for measuring. but now i'm stuck. i know it's there, i can eq it, but hell, i want to see if something i can do to fix it, correct it, whatever


i can try to do something tomorrow. ill have to dig up my umik and install the software on this pc and relearn how to use it. i havent messed with it in a while now.

awesome, thanks! there should be plenty of forum post for how to use REW, quick and dirty way to get it going


1) install rew
2) it should auto-recognize umik, and ask for the calibration file, supply it
3) mini-jack (headphone) out to RCA in for whatever amp you are using
4) SUPER IMPORTANT: turn off all processing on both the computer, and if you are using an AVR, be in 'direct mode' (denon term). basically NO signal processing. on your computer, go to windows:control panel:sound. Hit config: ensure they are set to 'full range'. Leave that menu, go to properties. Ensure there is no dolby, realtek, or 'enhancements tab' that has any box checked. goal is to get full range un-altered sound to the speakers for measurement. for your AVR, ensure audyssey is turned off and any other EQ modes (bass, treble enhancements...)
5) open 'signal generator', set a -12dbFS, and choose 'pink noise'. also open 'spl meter', set to 'C' in the weighting, hit the record button. 'play' the pink noise and increase volume on avr/computer until you get to 75ish db (pick whatever, so long as it's >65ish)
6) measurement: ensure it measures from 20hz to 20000hz, -12dbFS, hit start, post the pic
 

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really good thought, i'll give them a call for sure. i 100% had the same experience as you. two busted 5" midranges, completely separate packages. one package damaged, ruined the driver, the other package nothing, driver basket bent to hell.



i'd agree that people are thinking now it's a bright speaker, however ever measurement i've found on the internet is not measurably bright....and i get it, it's 100 bucks, and no one is likely giving a ****, or hell, even has the capacity for measuring. but now i'm stuck. i know it's there, i can eq it, but hell, i want to see if something i can do to fix it, correct it, whatever
Wow very informative write up. was able to just go ahead and plug it in and follow along. Split it into left and right speakers. According to the graph they are pretty flat. Maybe its just because im nearfield or maybe the style tweeter but theres just the slightest harshness to my ears. According to the graphs i dont know what im talking about.


Edit: not sure why but it kept dropping my images. heres the link to the imgur

https://imgur.com/a/Bdh8pYq
 

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Discussion Starter #18
Wow very informative write up. was able to just go ahead and plug it in and follow along. Split it into left and right speakers. According to the graph they are pretty flat. Maybe its just because im nearfield or maybe the style tweeter but theres just the slightest harshness to my ears. According to the graphs i dont know what im talking about.



ha yeah, the graphs are the most telling, however i dont see them attached to your post


two other quick things


when measuring, have the speaker hang off the desk a little, your first reflection point (the desk) will alter the measurement of just the speaker. youd want it there when yoi go to correct it, but not to see the pure response of the speaker



second, make sure to measure 1-3ft away from the speaker if possible and ensure to choose the proper mic calibration file. 90deg is for when you have the mic pointed at the ceiling
 

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Discussion Starter #19
also, some updated graphs of some additional measurements


one with the each of the individual drivers connected to the xover


then another set with just the raw drivers (and one full just to have a baseline comparison)



anyone with any additional thoughts?
 

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also, some updated graphs of some additional measurements


one with the each of the individual drivers connected to the xover


then another set with just the raw drivers (and one full just to have a baseline comparison)



anyone with any additional thoughts?
i think its the website. your graphs dont show either. i added a link above to the results.

https://imgur.com/a/Bdh8pYq
 
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