I’ve done measurements of the CHR70A. The test data looks good and so is the sound. The published frequency response from Markaudio is embellished to the extreme. They need to use a standard vertical scale of 50dB, not 100dB. It’s completely unnecessary considering the driver actually tests well. Why create and perpetuate a false standard where everything looks ruler flat?
https://josephcrowe.com/blogs/news/markaudio-chr70a-fullrange-driver
https://josephcrowe.com/blogs/news/markaudio-chr70a-fullrange-driver
Frequency response depends on the room and the enclosure, so I shouldn't trust the manufacturer's graph, lol.
Also, I don't think the frequency response graph has anything to do with how good or bad the sound is.
Also, I don't think the frequency response graph has anything to do with how good or bad the sound is.
I understand where you are coming from. Certain measurements can look good but the driver still sounds bad. However, if a comprehensive and careful test is carried out there will always be something that is revealed that explains the poor sound quality. It’s just not very common that people will carry out extensive testing that is revealing enough. For example, the graphs you show are not gated, so we have room reflections that mask the actual response of the driver. You need to test time domain measurements as well as harmonic and intermodulation distortion. Some drivers test amazingly well, and yet perform poorly on IMD. If not tested, then it leads to false conclusions about the general effectiveness of objective testing.
I understand Joseph Crowe's thoughts.
I have tried various methods of measurement in the past, but the measurement graphs do not match my aural perception, so I am now focusing on spectral comparisons between the CD source and the speaker playback sound.
Attachments
I like that you've included a polar map. Has it been normalised? That's a common thing but I'm not sure it presents the information at it's most useful.
IMD is very important.
I want to see IMD for MAOP drivers and Paper cones.
I think MAOP is best.
I want to see IMD for MAOP drivers and Paper cones.
I think MAOP is best.
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Yes, the polar map is normalized. The driver has a relatively consistent narrowing of directivity starting at around 4kHz which is nice. Overall coverage at 13kHz is similar to other drivers of its size. The main aspect is that the narrowing is gradual and even. Some drivers I’ve tested narrow sharply starting in the 8kHz region which gives an upper midrange heavy emphasis to the perceived in-room frequency response.
I've been listening to the CHR 70.3 for several years now. Ported and sealed with good results! They do benefit from an off axis orientation.
Larry
Larry
Are you speculating that MAOP would be the best for IMD? Or are you saying it’s subjectively the best based on your own listening?
Hi guys
I just get the CHR-70.3 from madisound on sale. Its going to be my first build. Now im triying to get a small enclosure with the lowest Fb/F3 possible 🍰 😏 .
So i have a few questions from what i found until now, hoping that you could help me out:
https://www.madisoundspeakerstore.com/pdf/markaudio-enclosure-plans/CHR70-BR.pdf
it is for a Gen 3 driver or the previous gen?
http://frugal-phile.com/boxlib/P10free/CGR-dCHR-Ken-301113.pdf
what are the Fb/F3 numbers on this design?
https://www.markaudio.com/wp-content/uploads/2021/08/Fenlon-70CHR.png
the same here, the Fb/F3 messures?
and me favorite one ...:
https://www.markaudio.com/wp-content/uploads/2022/09/CHR70.3-twin-vent.png
the big question for me on this one is if i will damage the design response and such if i move the ports to the front waffle
To choose this last one i will need to brind those ports on front, but if the response its damage im just not going to do it..and go for another box.
THANKS a lot for the help!
I will going to post the build process too.
from 🇨🇴
I just get the CHR-70.3 from madisound on sale. Its going to be my first build. Now im triying to get a small enclosure with the lowest Fb/F3 possible 🍰 😏 .
So i have a few questions from what i found until now, hoping that you could help me out:
https://www.madisoundspeakerstore.com/pdf/markaudio-enclosure-plans/CHR70-BR.pdf
it is for a Gen 3 driver or the previous gen?
http://frugal-phile.com/boxlib/P10free/CGR-dCHR-Ken-301113.pdf
what are the Fb/F3 numbers on this design?
https://www.markaudio.com/wp-content/uploads/2021/08/Fenlon-70CHR.png
the same here, the Fb/F3 messures?
and me favorite one ...:
https://www.markaudio.com/wp-content/uploads/2022/09/CHR70.3-twin-vent.png
the big question for me on this one is if i will damage the design response and such if i move the ports to the front waffle
To choose this last one i will need to brind those ports on front, but if the response its damage im just not going to do it..and go for another box.
THANKS a lot for the help!
I will going to post the build process too.
from 🇨🇴
It is a 4” driver.
And kudos for spending so much time complaning about MAs vertical axis scale.
1.5kHz is transition between pistonic and chaotic behaviour.
The illustration of what happens when you use a FR as a midTweeter is interesting. And the WAW stuff.
His test box is going to have its own issues.
Overall a video worth watching. Can’t comment on his comments on what they sound like.
dave
And kudos for spending so much time complaning about MAs vertical axis scale.
1.5kHz is transition between pistonic and chaotic behaviour.
The illustration of what happens when you use a FR as a midTweeter is interesting. And the WAW stuff.
His test box is going to have its own issues.
Overall a video worth watching. Can’t comment on his comments on what they sound like.
dave
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Your measurements clearly show that CHR70A has major and very audible distortions at 10 kHz. You need to low pass it at 9 kHz and add a tweeter, don't let it play like this.
We can stretch or shrink the vertical and horizontal scales.
I prefer to measure without smoothing, so how much smoothing is more important.
I prefer to measure without smoothing, so how much smoothing is more important.