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Discussion Starter #1
Been a while since I've tested anything, but I've had this Aura Sound NS6-255-8A sitting on my bench for a couple months now and figured I'd throw it on the baffle and run it through some Dayton testing gear as opposed to running the Klippel on it as that's a bit more involved. Though, if you guys are interested, I may try to put the Klippel LSI on it to see what the motor and suspension look like.


Here's the impedance sweep results:




The below is FR measured at 2.83v/1m, 0, 15, 30, 45, and 60 degrees with the accompanying polar. You can see I stitched NF and FF at approximately 400hz, as this is where they lined up best for all axes. My on-axis impulse is reflection free out to about 7ms so I ran up to that point, but still merged at 400hz. These are smoothed to 1/12 octave.







FR seems usable to about 3.5khz before the response gets pretty ragged. Also, looking at the impedance vs the FR, you can see a bump in impedance just before and after 4khz with a correlating bump in FR (and the same dip at 4khz in both). Honestly, I was expecting the bump in impedance to result in a dip in FR due to resonance . I'd like to hear what you guys think may be going on here. At approximately 5khz, the cone's modal issues crop up.

If I can find the time tonight, I'll try to run some IMD and HD tests on the drive unit as well.

- Erin
 

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doesn't look right, the Qts is too high, the impedance spike is too high...

too bad you didn't have an MR 6.5" woofer to compare with, the motors would tell the tale.

I motion for Klippel confirmation..
 

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Discussion Starter #3 (Edited)
It is what it is, my man. I recal'd the DATs before running it through. And it's never been off on any other measurements compared to the klippel.

The driver was brand new when I got it. And went through plenty of break in period.

The motor comparison wouldn't do anything to tell the tale regarding Qts given the suspension component.
 

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Discussion Starter #4
FWIW, I did think the same thing, though. Fs and Qts are not really close to spec. Though, moving mass and Qms are pretty close. Qes seems to be the component that is off the most. I haven't found any other 3rd party measurements to compare to.
 

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surprised to see it so smooth out to 3.5K though, and maybe the neo used for the motors is a variable.

that kick down at 30 degrees off axis would be noticeable if you're cutting them off at 12 db/oct above 4K I think...

these neo-radial motors should be pretty stable unless one of the magnets was loose in the ring, and creates that impedance wobble way high up?
 

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or, maybe it's the nickel-plating coming off again, a la Npdang's try outs on a sub back in the day...

but it's small signal parameters, so no go on DATS eval...

let's rip 50W at 1K into her and see if she snorts..
 

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oh, and the MR motors telling the tale, that's just my wishful thinking. I love their sound so it would be nice to know how different the MR motors are from the NS6, especially when the 5.25" car speakers (stage2rpm, or Ford GT/McIntosh) have such a wide voice coil in comparison.
 

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Cool to see you testing the NS6. I started with them mounted in the factory location in my door. They stayed there for about six months until I replaced them with 8" 8ohm Silver Flutes. Although the Flutes were quite nice I could not get them to sound as lively with female vocals as the Auras. The Auras were recently reinstalled in place of the Silver Flutes.
 

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Discussion Starter #9
some more info...

HD at 90dB/1m equivalent:





HD with a single tone in the spectrum view (I did this to verify the high odd order distortion seen above):




IMD at 90dB/1m:




IMD at 96dB/1m:





Note: IMD tones were 0dB at 55hz and -6dB at 440hz.

What you see in the above is a generally high odd-order distortion component. From the HD plots, to be below 3% at 90dB, these need to be played above 70hz. Though, that single number is somewhat fooling because there's a decent bit of THD throughout the driver as whole, with the midrange (200-1khz) being the cleanest portion under 1%. Outside of this, THD is above 1%. Comparing the IMD at 90dB vs IMD at 96dB, you can see the odd order distortion creeping up on the even order distortion. Given that 30dB down from the fundamental is the 3% distortion mark, you can see that at 96dB, the odd order distortion is above this value.
 

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numbers ain't so good, still they have something special about their sound. Maybe it's that the distorting parts don't affect the sound in a negative way. Like how it's said that 2nd order is pleasing. The high odd order distortion creeping in, I'd hope was a function of slightly less engineered suspension components and not a characteristic of the motor design, because I love these motors.

I'd hate to find out the motors are suspect to creating distortion a couple of tenths of percentage points over lesser products in the market.


But they sold these for under 10 a piece, I don't know if it should be expected to outperform drivers retailing in the forty dollar range.
 
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