Is the AE TD15M the ultimate mid driver?

[pk]

Hi,

The TD15M has impressive specs for a 15” (high efficiency, low mass, and very low Le) and looks – at least on paper – to be a super, large format, midrange driver (DR, not hornloaded). The idea of having a single driver covering from the whole 100-1,500 Hz seems attractive for sure.

I haven’t had a chance to hear the driver myself, but I would be very interested in hearing from people who has. I am especially interested in hearing from those of you who have compared it directly to ‘smaller’ dedicated mids (e.g. JBL 2118H / 2123H, PHL 4351 / 1120 / 1660, B&C 8PE21, etc.). My concern is especially about the quality of the response in the upper register. Is the TD15M as revealing in the 500-1,500 range as the smaller alternatives?

Thanks a lot in advance!

Best regards
Peter

[Brett]

I heard a pair in an active 2 way with CD/WG a year or so ago, and they were outstanding. I've also owned the JBL2123 and used them for a decade or more, but have not compared side by side, similarly I've heard the PHL1120/1660 a few times.

Now depending upon what you really want to do in your build, I'd say yes, it can do it and well.

FWIW, I own 12 AE TD drivers so am very biased.

[pk]

Hi Brett,

Thanks for replying!

Best regards
Peter

[pos]

The directivity narrowing cannot be avoided with a 15".
Even with a good cone geometry and the small "phase plug", the TM15 will be quite beammy at 1500hz, whereas a 10" or 12" driver would be around 90° there

[bwaslo]

The narrow directivity is exactly what you want if crossing to a constant directivity waveguide. I'm running TD15M (from 80 Hz to 1000Hz) crossed to SEOS15. The setup has the best midrange I've gotten in (obviously limited) experience, including SEAS
6.5" midwoofers, electrostats, and planar ribbons. Opinion only, ymmv.

[Charles Darwin]

Originally Posted by bwaslo

The narrow directivity is exactly what you want if crossing to a constant directivity waveguide. I'm running TD15M (from 80 Hz to 1000Hz) crossed to SEOS15. The setup has the best midrange I've gotten in (obviously limited) experience, including SEAS
6.5" midwoofers, electrostats, and planar ribbons. Opinion only, ymmv.

Wouldn't that depend on the dispersion of the waveguide?

If I were to use a WG with 90deg dispersion I would not want my mid/woofer have a narrower dispersion at the xover frequency.
That said if I were to use a 60deg WG a 15" crossed at 1.5k might be ok.

[badman]

The 15" size dominates the directivity, but the phase plug and cone profile have some effect. Crossing over high has its issues, but directivity in such cases tends to average reasonably well, it's not a deal-breaker but naturally best avoided where possible.

[pk]

Hi pos, bwaslo, Charles, and Badman,

Thanks a lot for responding!

I currently use the Beyma TPL-150H and consider to use the TD15M to as a mid-driver together with the Beyma. The Beyma has a constant 80° horizontal dispersion down to app. 1,200 Hz, so this would be the suggested crossover point.

Now, "djk" has provided the rule of thumb, that the frequency at which a given cone driver will beem relative to a given dispersion angle, can be calculated by means of the following simple equation:

1,000,000 / driver size in inches / dispersion in degrees = frequency

For an average 15" cone driver (whatever that is), the equation gives:

1,000,000 / 15 / 80 degrees = 833,3 Hz

That is quite a bit lower that the 1,200 cycles I am aiming for. However, the people at AE states that the TD15M have considerably wider dispersion than the average 15" woofer due to cone shape and the phase plug, but unfortunately I do not know how much wider. In case anybody knows whether the TD15M would have dispersion close to 80° around 1,200 Hz, I would very much like to know! Thanks!

Best regards
Peter

Originally Posted by bwaslo

The narrow directivity is exactly what you want if crossing to a constant directivity waveguide. I'm running TD15M (from 80 Hz to 1000Hz) crossed to SEOS15. The setup has the best midrange I've gotten in (obviously limited) experience, including SEAS
6.5" midwoofers, electrostats, and planar ribbons. Opinion only, ymmv.

[Charles Darwin]

May be a TD12M would be a better choice crossed at 1.2-1.5k?

[Audiodidakt]

I believe the cone and phaseplug is identical on all TD15-woofers, thus they have same dispersion-characteristics.

Here is measurement 0-20-40 degrees of th15x:
http://sites.google.com/site/driverv...uency-response

Best regards

Gisle