Looking for a ~5.5" mid and I see the Faital Pro 6RS140 being spoken highly of. For example, Troels uses it in his Loudspeaker center and raves about it. My problem with this (and other Faital drivers that have been measured) is that it has some fairly high distortion. In this case there appears to be a giant peak at ~1300 Hz as shown in Dickason's review linked below. I realize most of this is 2nd order harmonic (up to 4%), but the 3rd order also clears 1% in this range, which from my understanding should be clearly audible. Is the problem that other drivers are not better here? (Wondering about the SB Acoustics SB15CRC30-4, where the IMD has been measured but I can't find harmonic distortion tests) Or is it that the strong 2nd order harmonics are inoffensive enough and mask the 3rd order for most listeners?
https://audioxpress.com/article/test-bench-faital-pro-6rs140-midwoofer-midrange
https://audioxpress.com/article/test-bench-faital-pro-6rs140-midwoofer-midrange
Some type, amount of harmonic distortion can even be preferable subjectively for some. So "better" sounding is a subjective term.
But don't forget that the audioxpress HD test had done at 12.5 V, 104 dB/1 m.
But since the 6RS140 is a 6,5" driver, so it's more comparable to the SB17CRC35-4, so here it is:
https://hificompass.com/en/speakers/measurements/sbacoustics/sb-acoustics-sb17crc35-4
Anyway, harmonic distortion is just one property among many.
But don't forget that the audioxpress HD test had done at 12.5 V, 104 dB/1 m.
But since the 6RS140 is a 6,5" driver, so it's more comparable to the SB17CRC35-4, so here it is:
https://hificompass.com/en/speakers/measurements/sbacoustics/sb-acoustics-sb17crc35-4
Anyway, harmonic distortion is just one property among many.
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ha, and of course the SB17CRC has a nice big distortion peak right around 1700 Hz, but then that's far enough up that it might be part of the cone breakup and manageable with a series filter like in the Purifi guidance for their 6.5 (I guess). But yes, you are right, I'm not interested in going as big as the Faital, I thought it was a ~140mm frame but it's not. Just puzzled by all the Faital praise.
At 10cm which is where the mic actually was. Which is equivalent to 104db @ 1m (according to the article, I didn't do the math to confirm.)
Maybe you guys should read the review before drawing conclusions:
Dickason: "For the distortion measurement, I mounted the 6RS140 rigidly in free-air, and set the SPL to 104 dB at 1 m (12.5 V) using a pink noise stimulus. I measured the distortion with the Listen microphone placed 10 cm from the driver. This produced the distortion curves shown in Figure 15".
Dickason: "For the distortion measurement, I mounted the 6RS140 rigidly in free-air, and set the SPL to 104 dB at 1 m (12.5 V) using a pink noise stimulus. I measured the distortion with the Listen microphone placed 10 cm from the driver. This produced the distortion curves shown in Figure 15".
Try the Klippel listening test and see if you still have the same understanding of what level and type of distortion is clearly audible to you and others, (8003 paticipants as of 1/7/21, last time I checked).
https://www.klippel.de/listeningtest/
At 104dB at 1kHz, my hearing would distort, with this test is you can listen at a comfortable level while distortion is increased.
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I only knew this because I've seen other people complain about his inconsistent presentation of his measurements. To be fair, he does say it, but you have to be paying pretty close attention.
Not to mention different graph axis ALL the time.
Often the interesting part of drivers isn't even shown.
I have also seen mistake with the dB vs percentage graphs not showing the same results.
A couple of them seem to have mistakes as well, since they don't line up with other 3rd party measurements.
While those 3rd party measurements line up with each other.
I get that Vance wants to standardise measurements for 94dB/1m for Hi-Fi drivers and 104dB/1m for PA drivers, but measuring them at 10cm means that the mic sees +20dB. So we're talking 114 or 124dB for a pink noise stimulus, but for drivers that have a resonant peak- yes it's easily over 120/130dB that the mic is seeing. The Listen Inc. microphone is specified up to only 123/126dB for <1% THD (SCM3/SCM4 model)
It's not clear whether it's the Vance is using the older SCM3, or current SCM4, but either way, it's the mic distortion at 6.5KHz when it's observing 132dB, or driver distortion (eg. 500Hz to 1.x KHz) or a combination of both (quite possibly- mic is observing 130dB @~1.2KHz)
I do wish he would take more care in his distortion measurements.
Maybe take 3 measurements, 94dB + 10dB and -10dB, and we'd all know for sure.
For now, I'd look at @HiFiCompass for distortion measurements taken at 31.5cm when looking at high frequencies, or 20mm when looking at low frequencies.
Now, back to Faital. Much ado has been said about some Faital drivers, perhaps due to cost or availability.
I honestly don't like Faital's 100dB Y axis for frequency response measurements; 40-50dB is much better, but I'm not holding my breath.
In essence Faital have two midwoofers in their 6" lineup of neo drive motors with demodulation rings; and this one is the most balanced for hi-fi use. (larger x-max and voice coil, lower Fs; the trade-off being lower sensitivity than the 6PR160). But does that make it the RS140 outstanding?
No, but it's hard to find an off-the-shelf drive 6" midwoofer with 93dB/2.83V sensitivity at around EU/US$150. I could count on one hand similar drivers from 18Sound, Lavoce etc. The 6ND430 has a truncated frame that is a pain to mount, even though it's a arguably better performer.
There's just not that many around...
It's not clear whether it's the Vance is using the older SCM3, or current SCM4, but either way, it's the mic distortion at 6.5KHz when it's observing 132dB, or driver distortion (eg. 500Hz to 1.x KHz) or a combination of both (quite possibly- mic is observing 130dB @~1.2KHz)
I do wish he would take more care in his distortion measurements.
Maybe take 3 measurements, 94dB + 10dB and -10dB, and we'd all know for sure.
For now, I'd look at @HiFiCompass for distortion measurements taken at 31.5cm when looking at high frequencies, or 20mm when looking at low frequencies.
Now, back to Faital. Much ado has been said about some Faital drivers, perhaps due to cost or availability.
I honestly don't like Faital's 100dB Y axis for frequency response measurements; 40-50dB is much better, but I'm not holding my breath.
In essence Faital have two midwoofers in their 6" lineup of neo drive motors with demodulation rings; and this one is the most balanced for hi-fi use. (larger x-max and voice coil, lower Fs; the trade-off being lower sensitivity than the 6PR160). But does that make it the RS140 outstanding?
No, but it's hard to find an off-the-shelf drive 6" midwoofer with 93dB/2.83V sensitivity at around EU/US$150. I could count on one hand similar drivers from 18Sound, Lavoce etc. The 6ND430 has a truncated frame that is a pain to mount, even though it's a arguably better performer.
There's just not that many around...
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(Pleasant) H2 distorsion will probably mask most/all of the H3 distorsion. In combination with the high level I doubt it would be audible, at least in a home situation.
Engineers have been adding distortion to recordings for decades……even order….,the Gaussian blur of the commercial print art world. Classic 2way bookshelf speakers that slam the XO right at 2k create such a phase discontinuity where an entire soundfield is whipped into butter……smooth and tastes great…..,yes……but how much butter by itself can a person eat?
End of day?…..it’s still all quite subjective…..nearly as subjective as the palette. I hate Brussel Sprouts btw! Lol
End of day?…..it’s still all quite subjective…..nearly as subjective as the palette. I hate Brussel Sprouts btw! Lol