I have already taken IMD measurements of the Dayton RS180-4 and I made some comparison graphs of the Dayton to the Morel KW-1. Better IMD performance with the Morel at a slightly higher price.
You can read reports of drivers with big coils having a good "grip" on the cone. I found this to be true with the Morel and I found it to reproduce the quick note changes of the string bass in the song Feathered Indians by Tyler Childers.
You can read reports of drivers with big coils having a good "grip" on the cone. I found this to be true with the Morel and I found it to reproduce the quick note changes of the string bass in the song Feathered Indians by Tyler Childers.
Attachments
Here: https://purifi-audio.com/2019/12/12/imd/ and https://purifi-audio.com/2019/12/07/amfm/. In the thread on this forum, they mention a recent audio show where they added a 10hz sine wave to an audio file to demonstrate the above with music. Not dissimilar to what you are doing with 2-tone testing, but I like that they record it, since the raw measurements we have available to us does not show a problem, when audibly there is. And I've heard this sort of distortion as a typical way speakers hit their limits, sort of a robotic sound.
I've completed my testing of the Misco BWX-6502. It's a lightweight neo driver and has an impressive amount of clean deep bass for it's size.
It outperforms the Dayton Epique E180HE-44 in the upper bass IMD test (75 and 180hz two tone)
It also is not far behind the Purifi driver in most test.
I matched up the IMD graphs with data on the Dayton DCS165 classic subwoofer. The Dayton has good bang for the buck but started to complain at high excursion so I was unable to get a 40 and 96 hz test at 85 db.
I've also attached an updated chart that includes data from all 14 drivers I've tested in the 6-8" size.
It outperforms the Dayton Epique E180HE-44 in the upper bass IMD test (75 and 180hz two tone)
It also is not far behind the Purifi driver in most test.
I matched up the IMD graphs with data on the Dayton DCS165 classic subwoofer. The Dayton has good bang for the buck but started to complain at high excursion so I was unable to get a 40 and 96 hz test at 85 db.
I've also attached an updated chart that includes data from all 14 drivers I've tested in the 6-8" size.
Attachments
I've started a new thread for 8" driver testing here: https://www.diyaudio.com/community/...er-intermodulation-distortion-testing.387690/
Next up to report on is the Audio Technology (AT) C-Quenze 18 H 52 17 06 SD Midwoofer and the Dayton PS180-8. If you read about the AT driver on the manufactures website it says this driver is designed for high performance in the midrange. I found this to be true with my IMD midrange testing as I found this driver to It outperform the other 9 drivers I've tested so far in the 300 hz three tone IMD test.
During the time I had the AT in my 14 liter test box, I had the chance to visit an audio showroom that threw a party to showcase the new Klipsch Jubilee speakers. Of course during the demo the Klipsch speakers were played very loud and they seemed very clean at high spl. This is expected since they use 2 12" woofers in a horn loaded/ported enclosure that weighs 330 pounds (150kg). However, later on in the night some tracks were played at moderate levels and one was "Stretch of the highway" by James Taylor. Walking around the showroom I took note of the bass guitar sounding powerful and James's vocal sounded good as well. Upon coming home I played this same song through the AT driver. The same power of the bass guitar was there but I also heard a very clear attack and decay of a kick drum that shared the beat with the bass guitar. I'm not sure why the drum gets lost in the mix with the Klipsch speakers, In general horn speakers have increased group delay and energy storage than sealed boxes so this could be why. Sorry for the long story, but this made me question what an ultimate speaker to reproduce bass might be and also showed the strength of the AT in upper bass/low midrange reproduction.
The Dayton PS180-8 also does fairly well in midrange reproduction especially at lower volumes and at in the 800hz test. The driver changes character however at high spl and for this reason I did not take a 300hz measurement at 90db. Notice in the 300hz at 90 db IMD test I compared the AT driver to the Purifi.
The midbassIMD7 summary spreadsheet in post 46 is still the most up to date.
Let me know what other drivers you would like to see.
During the time I had the AT in my 14 liter test box, I had the chance to visit an audio showroom that threw a party to showcase the new Klipsch Jubilee speakers. Of course during the demo the Klipsch speakers were played very loud and they seemed very clean at high spl. This is expected since they use 2 12" woofers in a horn loaded/ported enclosure that weighs 330 pounds (150kg). However, later on in the night some tracks were played at moderate levels and one was "Stretch of the highway" by James Taylor. Walking around the showroom I took note of the bass guitar sounding powerful and James's vocal sounded good as well. Upon coming home I played this same song through the AT driver. The same power of the bass guitar was there but I also heard a very clear attack and decay of a kick drum that shared the beat with the bass guitar. I'm not sure why the drum gets lost in the mix with the Klipsch speakers, In general horn speakers have increased group delay and energy storage than sealed boxes so this could be why. Sorry for the long story, but this made me question what an ultimate speaker to reproduce bass might be and also showed the strength of the AT in upper bass/low midrange reproduction.
The Dayton PS180-8 also does fairly well in midrange reproduction especially at lower volumes and at in the 800hz test. The driver changes character however at high spl and for this reason I did not take a 300hz measurement at 90db. Notice in the 300hz at 90 db IMD test I compared the AT driver to the Purifi.
The midbassIMD7 summary spreadsheet in post 46 is still the most up to date.
Let me know what other drivers you would like to see.
Attachments
Thanks for your great work Mark!
Those who have worked with that AT driver have like it, but I've never seem measurements explain why, so your data is illuminating.
Most of the measurements of the driver have been to explain how it works as a mid-woofer, and there have been some designs using it as such. But it looks like it's particular strength is as a midrange- is my interpretation correct?
What about the 15H 52 12 06 SDKM?
Those who have worked with that AT driver have like it, but I've never seem measurements explain why, so your data is illuminating.
Most of the measurements of the driver have been to explain how it works as a mid-woofer, and there have been some designs using it as such. But it looks like it's particular strength is as a midrange- is my interpretation correct?
What about the 15H 52 12 06 SDKM?
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Tktran303, I sent Per Skanning an email about the 15H 52 12 06 SDKM and how it handles IMD. He replied:
The 15 H 52 12 06 SDKM is a true midrange, but not underhung.
We have never compared the underhung and overhung versions of 15 H 52 ** ** SDKM, but similar versions in 18cm size.
There was almost no difference between the two versions, with regards to distortion.
The SD system makes IMD very low in all drivers.
The 15 H 52 12 06 SDKM is a true midrange, but not underhung.
We have never compared the underhung and overhung versions of 15 H 52 ** ** SDKM, but similar versions in 18cm size.
There was almost no difference between the two versions, with regards to distortion.
The SD system makes IMD very low in all drivers.
Troels seems to like sligthy better the 16H than the 15H as a midrange. When you see the Sd of the 15, it is already big for a mid : about 95 cm².
Should such IMD be made at equal SD for proper benchmark ?
Also the Skaanings as many mid and midwoof, exhibit a little dip around 1.2K Hz that translate in a climbing thd here. Although if remember a test it is mostly H2 peak.
Thanks shrub0 for this work. I'd like tio know how is the kapton over the kapton plus aluminium difference in such tests.
Should such IMD be made at equal SD for proper benchmark ?
Also the Skaanings as many mid and midwoof, exhibit a little dip around 1.2K Hz that translate in a climbing thd here. Although if remember a test it is mostly H2 peak.
Thanks shrub0 for this work. I'd like tio know how is the kapton over the kapton plus aluminium difference in such tests.
I've always had a curiosity if the drivers used in commercial speakers are better than what is available to the DIY speaker builder. I recently had the opportunity to test a midrange built by Morel taken out a Magico S5. I've compared the Magico IMD measurements with the Purifi PTT6.5X04-NFA-01. To be fair I've tested the bass IMD of the Magico driver and it is crossed over to the woofers at 300hz in the S5 so it may be more a pure midrange than a midbass. I have found the Purifi to have cleaner IMD in all of the tests through the bass and midrange. In some of the tests the Magico has lower Harmonic Distortion (look for peaks at 80 and 120 hz in the 40 and 96 hz IMD test). However, I find low IMD to be more important than low HD. (see more about this here https://www.facebook.com/.../posts/1938870303135464/...
Please pay attention to the scale in the graphs as it is different in a few. In subjective listening I found the Magico to provide alot of detail in the midrange. It captured the vibrato really well of Pokey Lafarge in the album "Something in the Water."
Please pay attention to the scale in the graphs as it is different in a few. In subjective listening I found the Magico to provide alot of detail in the midrange. It captured the vibrato really well of Pokey Lafarge in the album "Something in the Water."
