[j-curve]

I had a chance to compare AT's "Air-Dynamic" open phones ATH-AD10, AD9, AD7 and AD5 side-by-side but since the source was muzak in a noisy store I can't offer a review, other than to say that the AD7 caught my attention because it sounded the least bright of the four and hence smoother.

AD10 and AD9

AD7 and AD5

However, AT's catalog is interesting as it provides cut-away technical drawings of these plus several of their closed phones which also use 53mm drive units. (Nominally! gerG's Nov 2002 measurements indicate an active diaphragm diameter of only 46mm). There seem to be three basic driver designs used. Each consists of a central dome whose diameter matches a voice coil diameter of between 18 and 25mm, plus a surround which takes up the remaining space out to 46mm.

Here are the plans and specifications, including my estimates of the voice coil diameters which are give-or-take a couple of millimetres. Within each design type there are of course slight differences in materials used, number of windings on the voice coil, etc.


Design "Type A", Voice Coil Diameter 22mm (approx.)

ATH-AD10 (Feb 1999) 38ohms 101dB/mW, OFC7N bobbin wound voice coil

ATH-W2002 (Oct 2001, 1000 units) 40ohms 102dB/mW, OFC8N bobbin wound voice coil

ATH-A100Ti (Nov 2001, 2000 units) 38ohms 100dB/mW, OFC6N bobbin wound voice coil, super hard coated diaphragm

Design "Type B", Voice Coil Diameter 25mm (approx.)

ATH-W11JPN (Dec 1998, 2000 units) 50ohms 98dB/mW, OFC8N bobbin wound voice coil, super hard coated diaphragm

ATH-W100 (Dec 1999) 48ohms 100dB/mW, OFC8N bobbin wound voice coil, super hard coated diaphragm

ATH-AD7 (Nov 2000) 32ohms 101dB/mW, CCAW bobbin wound voice coil

ATH-W11R (Dec 2000, 800 units) 48ohms 100dB/mW, OFC8N bobbin wound voice coil, super hard coated diaphragm

At a guess, the ATH-A9X (Oct 1997) (32ohms, 103dB/mW, CCAW bobbin wound voice coil) is also type B.



Design "Type C", Voice Coil Diameter 18mm (approx.)

ATH-AD9 (Feb 1999) 60ohms 102dB/mW, CCAW voice coil

ATH-AD5 (Nov 2000) 68ohms 101dB/mW, CCAW voice coil

At a guess, the ATH-A55 (Jul 2001) (60ohms, 102dB/mW, CCAW voice coil) is also type C.

[Edited Sept 17: Added the W11JPN]
[Edited Dec 20: My original voicecoil diameter estimates were about 13% high, based on gerG's more recent measurements of an actual AD10 driver. Effective diaphragm diameter should be around 46mm.]
[Edited Jan 2: Added release dates and limited edition #units.]

Keywords: audio technica audio-technica transducer transducers internal internals plan plans schematic schematics drawing drawings unit types different difference assembly construction

 

[puck]

i have listened to all of these cans as well. they all sounded good but i would agree that the ad7 caught my attention for being the best value for the money of the four open cans. however, the ad9 also seemed quite good. i was also in a store but it was only mildly noisy and they were playing some jazz and light rock through them.

also, i noticed that you mentioned angled drivers in some of the specs but not others. they all have angled drivers, it's just that some of the diagrams are side cutaways which don't show the driver being angled while others are top cutaways which do. i don't know why they did this differently for the various cans but they do all have angled drivers.

 

[Magicthyse]

So what does the discerning audiophile wear in and out in Japan? What's tops for style? What do people consider the best in sound? I would be particularly interested in 'outside' phones.

I would have imagined that due to the crowded trains, closed cans/canalphones were out of the question, due to the inability to judge a discreet fart properly?

 

[puck]

don't know what most people are using at home because i don't see many people listening to headphones when i go to their homes. as for outdoor stuff, most people seem to like ****! a lot of street styles and that sort of trash, cheep earbuds and the occational low end AT muffs. i live in the south so it might be different in tokyo but down here the only good headphones i see in public are my own. i have seen a lot of tv camera crew sound men with upper end AT cans though. i even saw one a few days ago with a pair of w100s that were beat to hell but obviously still working well.

 

[j-curve]

Quote:

they all have angled drivers

OK, thanks, I've edited out the bit about angled drivers.

 

[j-curve]

I'm reluctant to post this opinion since there's a headphone sound for everyone and I wouldn't want to discourage people from buying one of AT's open phones (and posting detailed and informative reviews about them here on Head-Fi!

)

However, when I finally got to audition the ATH-AD7 in a place quiet enough to make a judgement, there was something about the character of the sound which turned me off. It's a kind of a whistling quality, obviously not an actual resonant whistle but something with the same aftertaste.

The way it felt next to an HD600 was this: when you hear the glister on the Senn's winds and strings you might suspect a smoke-and-mirrors trick, but when you consider how the instruments should sound at the position of the microphones (as opposed to the seats in the auditorium) then it doesn't seem so unreasonable. A bit like looking at a sportscar and noticing the glint of the sun off one of its windows. It would be easier to admire the car without the sun's reflection but it's probably meant to be there.

By comparison, the Audio-Technicas are like cruising along in the sportscar but after a while, having to check if the window is properly closed. Granted, the AD7 is a mere fraction of the cost of the HD600, or even the HD580 here. Outside Japan those economics don't help you though.

The AD7 disappointed me because I had hoped it would sound like an open version of the ATH-W100, with all the benefits that would bring. I didn't spend much time with the AD5 or the AD9, beyond that required to confirm that they share the overall character of the AD7. The AD10, which I have heard only with muzak, has a stronger upper midrange than her sisters, in a similar way that the A100Ti closed phone does next to the A9X. That kind of emphasis doesn't appeal to me, and the economics are out the window.

 

[j-curve]

Obviously I should have spent more time with the AD5. Recently I had an opportunity to sample all four of AT's open phones side by side through an AT-HA2002 amp, fed by a high-end Sony CD player with the 3rd movement of the Dvorak cello concerto. An HD580 was also on hand, which became a kind of default reference for the comparison.

Bearing all that in mind, my ranking of the four (purely on the basis of sound) is as follows:-
1st AD5
2nd AD7
3rd AD10
4th AD9

Taking price into account, the range seems even further out of whack, completely upside down in fact. Does this mean I've got cheap ears? Or the harder AT's engineers try to pack high-tech into an open phone, the harsher the treble becomes? They all have varying degrees of what I referred to above as the "whistle" effect, which in the case of the AD9 would cause me fatigue in a short while. However, the AD5 is much better controlled in this regard, and in direct comparison with the HD580 is well balanced tonally. I don't consider the AD5 lacking in bass, but fans of the HD580's ample low end may feel differently. As you would expect the AD5 can't match the detail and clarity of the HD580, but at less than 30% of the price (here) it is a definite contender for a budget open phone.

 

[Steve999]

Hey j-curve, thanks, that's awesome to know. I've always got my eyes and ears open for a fourth set of great and relatively cheap phones (in additon to the Grado SR60s, Sennheiser HD 497s, and Sony V6s), but haven't heard of, or heard, anything to make me jump. Maybe I should think about some ATs.

Any more views on these?

 

[j-curve]

Design "Type A", Voice Coil Diameter 22mm (approx.)

ATH-A900 (Oct 2002) 40ohms 101dB/mW, OFC bobbin wound voice coil

ATH-A1000 (Nov 2002, 3000 units) 40ohms 103dB/mW, OFC6N bobbin wound voice coil

ATH-W1000 (Nov 2002) 40 ohms 100dB/mW, OFC8N bobbin wound voice coil

Design "Type C", Voice Coil Diameter 18mm (approx.)

ATH-A700 (Oct 2002) 64ohms 102dB/mW, CCAW voice coil
(possibly identical to the AD9)

ATH-A500 (Oct 2002) 64ohms 100dB/mW, CCAW voice coil
(possibly identical to the AD5)

[Edited Jan 3: Added release dates and limited edition #units.

 

[j-curve]

These four are open headphones due for release next week. This year's surprise is the introduction of a 40mm drive unit for the two budget models. All previous drivers in this thread have been 53mm units.



Design "Type D (40mm driver)", Voice Coil Diameter 20mm (estimated)

ATH-AD300 (Oct 2003) 32ohms 96dB/mW

ATH-AD400 (Oct 2003) 32ohms 96dB/mW, CCAW voice coil

The other two are more familiar 53mm drivers:-

Design "Type C", Voice Coil Diameter 18mm (approx.)

ATH-AD500 (Oct 2003) 66ohms 99dB/mW, CCAW voice coil

I have serious doubts about this cutaway image. Everything points to "Type C" except the picture, which shows a "Type A" driver. I'm going with the numbers until proven otherwise.


Design "Type A", Voice Coil Diameter 22mm (approx.)

ATH-AD700 (Oct 2003) 32ohms 98dB/mW, CCAW bobbin wound voice coil

 

[D-EJ915]

The new ones are fairly hideous though, I hope the next series of ART Monitors looks hot like the ones now. Nice compilation.

 

[j-curve]

Design "Type A", Voice Coil Diameter 22mm (approx.)

ATH-L3000 (Nov 2003, 500 units) 48ohms 104dB/mW, OFC8N bobbin wound voice coil