3"or 4" driver with very good dispersion and high xmax? - Page 22 - diyAudio
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Old 25th February 2014, 02:19 AM   #211
dewardh is offline dewardh  United States
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Quote:
Originally Posted by markus76 View Post
The real problem with the Alpair driver (besides the highly misleading vendor supplied magnitude response graph) is its off-axis behavior. A power response hole followed by a huge peak.Click the image to open in full size.
The 30 degree curve is actually somewhat better than one would expect . . . apparently the "button" tweeter is working, at least out that far. The 60 degree curve is exactly what one would expect from a cone that size . . . look at the TG9 at the same angle.
http://www.tymphany.com/files/TG9FD-...0%20090612.pdf
I don't know what you were expecting to happen when cone diameter becomes greater than the radiated wavelength, but now you know what actually happens. Off axis nulls. The 7.3 does a better job of controlling them through a reasonable listening angle than other drivers of that size, but out at 60 degrees and beyond you can't beat physics.

This is all something with which one becomes immediately and intimately familiar if you do dipoles, because off-axis behavior is the meat and potatoes of dipole design.

Last edited by dewardh; 25th February 2014 at 02:25 AM.
 
Old 25th February 2014, 04:24 AM   #212
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Originally Posted by chrisb View Post
I've never heard the little Vifa displayed in xrk's most recent post
We have 4 of them sitting on my bench.

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Old 25th February 2014, 04:55 AM   #213
xrk971 is offline xrk971  United States
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The Vifa has about the same cutout dia as the 85wk so you may be able to do drop in replacement for sealed or nominal 10:1 TL alignments to check it out quickly. There really is not any break-in required that I can tell. I have measured drivers used daily for a year with a brand new one and the response is very consistent. Have fun with them - they are a great sounding unit for a nice low price.
 
Old 25th February 2014, 10:30 AM   #214
Elias is offline Elias  Finland
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Originally Posted by thedoc View Post
The Faital full rangers do sound quite nice. I have 3 3FE25 that I use in a trifield setup in my bedroom. The way they image is fantastic.
Why the image is "fantastic" must be because of the Trifield, not because of the driver.


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Old 25th February 2014, 11:49 AM   #215
erkki1 is offline erkki1  Finland
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The TG9 is easy to EQ to reach very smooth FR:

Click the image to open in full size.
Distance 40cm, 1/12 oct smoothing. TABAQ box with excessive stuffing.

In final placing the room effect and HF area dispersion have required tweaking of the BSC filter, as this (on axis) FR is good only in very close range.
 
Old 25th February 2014, 12:06 PM   #216
xrk971 is offline xrk971  United States
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Quote:
Originally Posted by dewardh View Post
I don't know what you were expecting to happen when cone diameter becomes greater than the radiated wavelength, but now you know what actually happens. Off axis nulls. The 7.3 does a better job of controlling them through a reasonable listening angle than other drivers of that size, but out at 60 degrees and beyond you can't beat physics.
You can't beat physics but the TC9FD apparently is using physics to its full extent because that huge dip at 7kHz is not there. Here are results of the TC9FD measured for 0 deg thru 90 deg. Presented on same vertical -10dB to 110dB scale as the A7. This was measured at 1 m away by moving the mic and leaving speaker stationary relative to room.

(calibrated mic and DAC using Dayton UMM-6)

These are for the dual driver Nautaloss II:

Click the image to open in full size.

These are for the single driver Nautaloss I:

Click the image to open in full size.
Attached Images
File Type: png nautaloss-ii-2-drivers-polar-1m.png (116.1 KB, 1798 views)
File Type: png nautaloss-i-1-driver-polar-1m.png (115.1 KB, 652 views)

Last edited by xrk971; 25th February 2014 at 12:19 PM.
 
Old 25th February 2014, 12:36 PM   #217
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With all the respect due to your obviously very good measurements X (I have no query at all out to ~30 degrees since they concur well with others I've seen for this unit) -out to 90? I would have severe reservations to how accurate they genuinely are. I stress no offense etc. of any kind is meant by that. But you ask any manufacturer or pro-testing body whether they think high off-axis measures are likely to be particularly accurate without full industry standard test gear in an anechoic chamber. With very few exceptions, you'll get the same (polite) answer -viz. 'no'. YMMV as always of course & doesn't alter the fact that the above is clearly very good indeed in terms of linear FR behaviour.

With that said, the TC9 should certainly have superior HF dispersion to the Alpair 7, since, notwithstanding the latter being a good performer in this regard for a unit of its size, the Vifa is about 28% smaller, which is an advantage in this regard.
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Old 25th February 2014, 12:37 PM   #218
Squeak is offline Squeak  Denmark
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16 kHz under 10 dB down at 45! That is quite amazing. I doubt you'd find the need for any kind of slot or lens to make that better. Is 50 Hz (10 dB down) the limit of how low it will go in an optimal cab?

Last edited by Squeak; 25th February 2014 at 12:39 PM.
 
Old 25th February 2014, 12:42 PM   #219
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I have some reservations about > 30 degrees off, although I'd expect the TC9 to do well.

Probably -I wouldn't want to push it any harder, or even so hard -HD + potential FMD would not be pretty. Good driver though it is, it's still a 3 1/2in unit with about 5.5in^2 cone area so it can't shift much air. Not that it matters, I rather like them since while there are some things you might wish they did more of, they don't do anything annoying. Which is a bigger deal than it sounds / reads, if you know what I mean.
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Old 25th February 2014, 12:50 PM   #220
Squeak is offline Squeak  Denmark
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But they are dirt cheap. You could buy 2 or more for the same price as the "low end" MA drivers (CHX-70 and the small Alpair).
Angled arrays or line arrays (Roger Russell) would give you any kind of dispersion you'd want and better low end (two drivers should be able to hit 50 without straining too much and four would touch the mid 40s).

Last edited by Squeak; 25th February 2014 at 12:56 PM.
 

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