I'm not a fan of cone mids that run in breakup mode close to or at xover, especially when you put some decent power into them.
This type of driver used this way may sound sweet and euphoric at lower levels, but they fall apart and start shouting when they get loud. The Audax PR170MO is like this along with many other ultra light weight cone drivers with some healthy BL. This is also why you'll never get real treble from a FR whizzer cone driver. The music turns into hash and distorted sizzle. The only answer is using a driver small enough to play higher up and combine it 1st order with a woofer, like a FAST design.
A decent dome mid will always be cleaner in its passband than a cone driver. You just need one with enough xnax so you don't need to cross it higher and lose the benefit of using one in the first place. In the case of the MD60-N, there isn't enough xmax to cross it under 1000. They should have compromised and given it more xmax instead of the higher sensitivity. Otherwise it would / could have been a great dome mid.
This type of driver used this way may sound sweet and euphoric at lower levels, but they fall apart and start shouting when they get loud. The Audax PR170MO is like this along with many other ultra light weight cone drivers with some healthy BL. This is also why you'll never get real treble from a FR whizzer cone driver. The music turns into hash and distorted sizzle. The only answer is using a driver small enough to play higher up and combine it 1st order with a woofer, like a FAST design.
A decent dome mid will always be cleaner in its passband than a cone driver. You just need one with enough xnax so you don't need to cross it higher and lose the benefit of using one in the first place. In the case of the MD60-N, there isn't enough xmax to cross it under 1000. They should have compromised and given it more xmax instead of the higher sensitivity. Otherwise it would / could have been a great dome mid.
You can run them way lower.
They have higher H2 but H3 is low and stays there. And don't forget - at crossover frequency the level of the driver is already 3-6dB down! This couteracts a rising THD of domes at lower frequency.
The lower limits of any driver depends on how much headroom a design calls for.
I wonder if you did some testing not only at 2.83V, but at higher levels, will the distortion will go up faster than the SPL?
The graph shown may be somewhat misleading to some readers- one may be be tempted to say it can go as low as 200Hz, as distortion does not appear to be rising. Can AP show the distortion in relative terms? (dBr or %) This is sometimes an aid to interpreting the useful lower limit.
The mechanical parameters of this driver (2.5” piston on sealed chamber with 0.5mm x-max) the excursion limited SPL is 80dB at 200Hz. So yes it can do 200Hz, but only at very quiet levels.
Experienced readers looking at your your graph @IamJF would still say that the lower limit is 700Hz.
But I think a lot of DIYers were hoping that this dome could do ~300Hz, like AnoTher dome from the 20th Century.
It certainly can’t do this at reference levels (105dB @ listening position)
I wonder if you did some testing not only at 2.83V, but at higher levels, will the distortion will go up faster than the SPL?
The graph shown may be somewhat misleading to some readers- one may be be tempted to say it can go as low as 200Hz, as distortion does not appear to be rising. Can AP show the distortion in relative terms? (dBr or %) This is sometimes an aid to interpreting the useful lower limit.
The mechanical parameters of this driver (2.5” piston on sealed chamber with 0.5mm x-max) the excursion limited SPL is 80dB at 200Hz. So yes it can do 200Hz, but only at very quiet levels.
Experienced readers looking at your your graph @IamJF would still say that the lower limit is 700Hz.
But I think a lot of DIYers were hoping that this dome could do ~300Hz, like AnoTher dome from the 20th Century.
It certainly can’t do this at reference levels (105dB @ listening position)
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Look - it can easily do higher levels. I'm not talking about stuff I didn't test 
It has high H2 levels but H3 stays low, even at low frequencies. 300Hz is always a huge stretch for a dome midrange, even the 3". 400-500 is realistic with Bliesma 3" but 500-600 is good for the 2,5". 110dBSpl/1m is at 70W and sine - not wideband noise. With music they can deliver more for sure.
You can use 2 in DApollito if you huge SPL, the frontplate can be routed to get closer to the tweeter.
It has high H2 levels but H3 stays low, even at low frequencies. 300Hz is always a huge stretch for a dome midrange, even the 3". 400-500 is realistic with Bliesma 3" but 500-600 is good for the 2,5". 110dBSpl/1m is at 70W and sine - not wideband noise. With music they can deliver more for sure.
You can use 2 in DApollito if you huge SPL, the frontplate can be routed to get closer to the tweeter.
Thanks for your great work, very appreciated!
This also shows the difference to a 3" mid dome pretty good. A Bliesma would do 100dBSpl at 4V instead 11V. THD is 20dB lower. But of course - you would not reach down to 200Hz.
@IamJF
Those are measurements of a single MD60?
According to your excellent measurements. It can hit 110dB at 600Hz.
And 4% THD at 600Hz is an acceptable limit for that single driver?
I think your data is very clear. Thank you.
I think my tolerance for distortion or exceeding x-max may be lower than yours, that is all (eg. 110dB at 600Hz is 1.5mm; 3 times the rated x-max)
Those are measurements of a single MD60?
According to your excellent measurements. It can hit 110dB at 600Hz.
And 4% THD at 600Hz is an acceptable limit for that single driver?
I think your data is very clear. Thank you.
I think my tolerance for distortion or exceeding x-max may be lower than yours, that is all (eg. 110dB at 600Hz is 1.5mm; 3 times the rated x-max)
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Only dull-minded people go crazy about meaningless numbers , they are numberphiles!
Scientific research decades ago have shown that human ear is self-generating massive harmonic distortion , at 90dB well beyond 1% and up to K4 !!!
No wonder , it is a mechanical device with poor linearity!
Go on polishing your chromium numbers and ignore reality - you are the chosen few!
Scientific research decades ago have shown that human ear is self-generating massive harmonic distortion , at 90dB well beyond 1% and up to K4 !!!
No wonder , it is a mechanical device with poor linearity!
Go on polishing your chromium numbers and ignore reality - you are the chosen few!
Btw - I want these danish wonderdomes with a titanium carrier for the voice coil .. and well ventilated by a row of small holes along the perimeter , thanks in advance and stay tuned for my heavenly advices
ps .. I got four of these limited edition heavenly devices ... https://www.poweraudio.pl/scan-speak-d2604832002-limited-edition-p-4018.html
ps .. I got four of these limited edition heavenly devices ... https://www.poweraudio.pl/scan-speak-d2604832002-limited-edition-p-4018.html
The best music for the best speakers , impressive sound :
The whole album :
Btw - regarding the 1st Track : Mother Long Tongue means a woman who's talking badly behind the back of other people ... I thought originally the singer sounds like Michael Prophet! (Jamaican reggae star in the late 70ties) But it is a different singer ....
The whole album :
Btw - regarding the 1st Track : Mother Long Tongue means a woman who's talking badly behind the back of other people ... I thought originally the singer sounds like Michael Prophet! (Jamaican reggae star in the late 70ties) But it is a different singer ....
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There were some running changes made to the MD60-N, which looked to be related to the dampening right behind the dome as well as the VC former. I had the first gen MD60-N open and found an unvented Alu VC former. That may be why the fundamental resonance peak had another peak right next to it. The double hump impedance usually means HD trouble down low at Fs.
Looking at the posted graph and measurements above, it looks like these are from the current production model. I wanted to love this mid when it first came out, but was disappointed based on my initial findings. It may have been improved to the point its worth giving another listen. The higher sensitivity is attractive to me if it doesn't compromise output capability in the lower mids, forcing a higher xover if one wants more SPL. If those measurements are accurate, there may be some hope. The old version has a big odd order HD peak around 1k, which was verified by Hificompass. That was a deal breaker for me and explained why I heard what I did.
The Scanspeak D7608 is also limited by low xmax, but it has more SD to compensate. It also relies on proper rear dampening to get the best from and this greatly effects low mid output capability. I usually run two of them in MTM or MMT if I need more output.
The other thing to consider before dismissing a driver for low published xmax is some motors are more linear beyond theoretical VC excursion limits, so its important to check this stuff out before moving onto the next greatest thing. In the case of the MD60-N, the even order harmonics aren't necessarily a bad thing. The more detrimental odd order stuff on the other hand can be harder to tolerate if you're sensitive to that sort of thing. Some people swear its not that audible, but I disagree.
So maybe I'll give the MD60-N another chance now that it appears to be improved.
In the case of the first gen MD60-N, the posted HD measurements below are showing elevated H3 and H5 around 1k, which are high in relation to even order H2 and H4. The ones I tried sounded very shouty when pushed harder and not in a linear way. I did quick HD measurements in Clio a few years back and got very similar results as Hificompass. Hopefully this has changed with the revisions.
Looking at the posted graph and measurements above, it looks like these are from the current production model. I wanted to love this mid when it first came out, but was disappointed based on my initial findings. It may have been improved to the point its worth giving another listen. The higher sensitivity is attractive to me if it doesn't compromise output capability in the lower mids, forcing a higher xover if one wants more SPL. If those measurements are accurate, there may be some hope. The old version has a big odd order HD peak around 1k, which was verified by Hificompass. That was a deal breaker for me and explained why I heard what I did.
The Scanspeak D7608 is also limited by low xmax, but it has more SD to compensate. It also relies on proper rear dampening to get the best from and this greatly effects low mid output capability. I usually run two of them in MTM or MMT if I need more output.
The other thing to consider before dismissing a driver for low published xmax is some motors are more linear beyond theoretical VC excursion limits, so its important to check this stuff out before moving onto the next greatest thing. In the case of the MD60-N, the even order harmonics aren't necessarily a bad thing. The more detrimental odd order stuff on the other hand can be harder to tolerate if you're sensitive to that sort of thing. Some people swear its not that audible, but I disagree.
So maybe I'll give the MD60-N another chance now that it appears to be improved.
In the case of the first gen MD60-N, the posted HD measurements below are showing elevated H3 and H5 around 1k, which are high in relation to even order H2 and H4. The ones I tried sounded very shouty when pushed harder and not in a linear way. I did quick HD measurements in Clio a few years back and got very similar results as Hificompass. Hopefully this has changed with the revisions.
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This is why I generally view Xmax for what it is -i.e. a very approximate guideline for when distortion values at various drive levels aren't available. There isn't even any industry-wide agreement about what it is (other than the rather fuzzy 'er, it's a value for motor linearity [definition carefully avoided]' let alone any consistent method for generating a single numeric value for it, as though it were some kind of brick wall boundary between acceptable / unacceptable. A few years ago I tried to do a count of different methods put forward for creating an Xmax figure. I gave up at 12 with plenty more to come, all of which give different values if applied to the same drive unit. Consistency, thy name is audio.
Hello Sir!
looks like SBA has already made the change to a non-conductive former! (higher Qms)
Can you please show us the impedance plot of your MD60N ??
Thanks for your comments , well appreciated!
This wonderdome from SBA is getting better and better .. the guys (and girls?) at Dayton Audio are smashed to the ground
Return of the classical 3-way studio monitor in compact size to the market?
Death to all 2-way sound betrayers!
HOLY TRINITY ;-)
I will have to have a look. But normally do 4th order (for sure between mid and tweeter). About 1,9-2kHz for the tweeter and 5-600 for midrange.
The MD60-N is not a super low THD speaker. But it's mainly H2 which is very hard to recognise with music. And at that high levels the ear produces itself already harmonics and masks these. And WHEN you can hear them they are not sounding bad, I know this from my BMS PA drivers at very high levels. They sound more "HiFi" what is actually nice with DJ stuff but can be not wanted for live music (doesn't sound as "real", a little to nice. But WAY better as these old B&C or JBL 2" drivers with resonances >8kHz)
And I also have 2 different versions of MD60-N and did some experiments - the driver is very sensitive about the damping in the backchamber! I would have needed to 3D print a new backchamber for my project cause it was to deep so did some trials. But the the M74 appears and fitted the project better - so skipped the MD60-N. Still use them in my reference speakers (these where the prototypes for my other project) but will upgrade to M74B in the next months.
Please let's not forget the Swans/Hivi-research domes DM7500 & DM7600 !!!
https://www.soundimports.eu/en/hivi-dm-7500.html
https://www.parts-express.com/HiVi-DM-7500-3-Soft-Dome-Midrange-Driver-6-Ohms-297-470?quantity=1
DM7600 is hard to get .... maybe price for a pair(?) :
https://de.aliexpress.com/i/1005004670093212.html?gatewayAdapt=glo2deu
https://www.swanspeakers.com/product/view?id=1174
https://www.soundimports.eu/en/hivi-dm-7500.html
https://www.parts-express.com/HiVi-DM-7500-3-Soft-Dome-Midrange-Driver-6-Ohms-297-470?quantity=1
DM7600 is hard to get .... maybe price for a pair(?) :
https://de.aliexpress.com/i/1005004670093212.html?gatewayAdapt=glo2deu
https://www.swanspeakers.com/product/view?id=1174
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FreqRes is much worse than Sig120 by Dayton Audio , data sheet says nothing about the material of the inverted dome , could be it is not aluminium and the reason for the not so well performing diaphragm!
Why not find out for yourself? Buy two check them out and please resport here!
If I remember correctly (old brain like swiss cheese holez) this item is no longer in production and I have doubts that reptiloid Kill Gates while financing nearly everything on this weird planet , will fit the M.O.Q. to start a new production to flood us with new happy pills for our beloved hobby
Btw - this happens to your brain if you take too much pills or the wrong ones , is this art or just milking people with crap "music" :
Looks like a candidate that qualifies easily for the "worst performance of all times" Top 100 !!!
Why not find out for yourself? Buy two check them out and please resport here!
If I remember correctly (old brain like swiss cheese holez) this item is no longer in production and I have doubts that reptiloid Kill Gates while financing nearly everything on this weird planet , will fit the M.O.Q. to start a new production to flood us with new happy pills for our beloved hobby
Btw - this happens to your brain if you take too much pills or the wrong ones , is this art or just milking people with crap "music" :
Looks like a candidate that qualifies easily for the "worst performance of all times" Top 100 !!!