True, my sweet spot is kind of narrow but I can't really expect a big big sound in this small room anyway. There are some recordings that are amazingly spacious sounding like Chris Cornell's live acoustic rendition of Billy Jean but there are not that many that I know of. Most studio albums sound like they were recorded in a studio. I actually like things sounding like how they should sound.
That tweet has nice low frequency extensionI like it!
It sure looks like it. Right now I just measured FR but as a dipole since I don't have a test box for it yet, so I just put a pillow behind it, lol. The low end seems to be there, but it is plagued with cancellations from reflections, so lots of dips and what not. The real test IMO is in it's actual intended environment, which in my case would be as a monopole. Time to rig up a test box, hopefully on the weekend.
Don't forget the Dayton AMTPRO-4 for a low-reaching mid-tweeter. Here it is with EQ applied. . Good down to almost 800Hz (with a high-order HPF) if you can live the the not-so-low distortion.
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Use close mike measurements.
Use far field to set relative levels.
Yup I think I'll have to, but I'm still gonna build a test box since I have to test two different filling materials as well to see what can give me cleaner sound: standard acoustastuff polyfill from P.E. or Mundorf Angel Hair.
How does your Aurum Cantus perform ? Especially regarding vertical dispersion. I know such ribbons and AMTs mostly have rather limited vertical dispersion which is not a problem if they're properly aligned with the listening position (or vice versa).
The question is rather: are they VERY directional vertically, or just a little bit ? I'm aiming for the AST25120 but considering the Mundorf hifiAMT®29CM1.1-R too since I saw their AMTs in this thread (thank you). But not decided yet between the two. (What makes me want the Mundorf is max power handling, I'll have a rather big 3-way but for normal listening levels the Aurum Cantus is my first choice now).
Especially regarding vertical dispersion. I know such ribbons and AMTs mostly have rather limited vertical dispersion which is not a problem if they're properly aligned with the listening position (or vice versa). The question is rather: are they VERY directional vertically, or just a little bit ? I'm aiming for the AST25120 but considering the Mundorf hifiAMT®29CM1.1-R too since I saw their AMTs in this thread (thank you). But not decided yet between the two. (What makes me want the Mundorf is max power handling, I'll have a rather big 3-way but for normal listening levels the Aurum Cantus is my first choice now).
How does your Aurum Cantus perform ?
The question is rather: are they VERY directional vertically, or just a little bit ? I'm aiming for the AST25120 but considering the Mundorf hifiAMT®29CM1.1-R too since I saw their AMTs in this thread (thank you). But not decided yet between the two. (What makes me want the Mundorf is max power handling, I'll have a rather big 3-way but for normal listening levels the Aurum Cantus is my first choice now).
Preliminary testing looks good, but so far I've only checked FR and harmonic distortion. The only thing I didn't like about the FR is that the top-end tanks on the very high end, more so than I thought it would. But then again, I need to do more checks and vary the placement as well to make sure it wasn't a faulty measurement.
I don't check for dispersion because I can and will direct the sound to my ears without any compromise with which ever AMT I decide to use.
It's just not something I personally need to worry about. But, from what I have read, they will have similar dispersion as any other radiator with a similar sized aperture with little to no faceplate assistance via bevels or radii.Granted it doesn't look anywhere near as good as the Beyma, this was with no rear enclosure, so I'm sure this being an open-back dipole would play a part in measurements of both FR and HD.
Harmonic Distortion
2.83V RMS sensitivity, 1m, open dipole, with felt pad, and acoustic foam behind driver
One very interesting thing I noticed (both with this and the Beyma TPL-150H), is that with high drive levels (~20V, ~120dB/ 0.5m IIRC), is that the low-end increases more than the rest of the curve does. I don't know if that is an artifact of the room, or the inherent behavior of the driver, or just faulty measurement.
Here you can see the 2.83V FR measurement, and also the high level FR. The dip below 1,5kHz isn't so pronounced when running a high drive level.
I'm off for vacations in two weeks, so I'll be testing it with an enclosure behind it. What I really like about it, is that the behavior below 2kHz is well controlled, relatively speaking. Notice how the HD doesn't have a huge spike when approaching down to 1kHz (like other AMT's I have tested). FR shows good low-end behavior as well.
Harmonic Distortion
2.83V RMS sensitivity, 1m, open dipole, with felt pad, and acoustic foam behind driver
One very interesting thing I noticed (both with this and the Beyma TPL-150H), is that with high drive levels (~20V, ~120dB/ 0.5m IIRC), is that the low-end increases more than the rest of the curve does. I don't know if that is an artifact of the room, or the inherent behavior of the driver, or just faulty measurement.
Here you can see the 2.83V FR measurement, and also the high level FR. The dip below 1,5kHz isn't so pronounced when running a high drive level.
I'm off for vacations in two weeks, so I'll be testing it with an enclosure behind it. What I really like about it, is that the behavior below 2kHz is well controlled, relatively speaking. Notice how the HD doesn't have a huge spike when approaching down to 1kHz (like other AMT's I have tested). FR shows good low-end behavior as well.
I guess you could say the AST30130 definitely has it's advantages and disadvantages, but I guess the same applies to any speaker.
I'm going to revisit my Hygeia RT-5002's to see if I notice the same change in behavior in their low-end.
For this test they were about 12in/30cm from the backwall, with insulation behind them. One thing I've learned is that every little thing makes a change in the response & measurements.
I'm going to revisit my Hygeia RT-5002's to see if I notice the same change in behavior in their low-end.
For this test they were about 12in/30cm from the backwall, with insulation behind them. One thing I've learned is that every little thing makes a change in the response & measurements.