[Skeeboingen]

Hello all, I am thinking of using a Dayton AMTPRO-4 as an open baffle dipole midrange.  Wondered if any of you have used it and what you thought of it?  Thinking of Hi-Vi M6N for a woofer and some other ribbon or planar for a tweeter with crossovers at 1000 and 5000 Hz.

~S

[JohnR]

Here's one usage:

http://www.audiocircle.com/index.php?topic=126622.0

As a dipole, you may find you get better polars with it turned around backwards. I found it a very clean sounding driver, the limitation is the vertical dispersion.

[matevana]

That's my design that John linked to above so I have first hand experience in using this driver. Most drivers based on the AMT-Heil air motion transformer are very transparent and natural sounding. But I also found the vertical window to be a very 'narrow slice' which can be a limiting factor in any design. I built the baffles to place the AMTPRO-4 exactly at my ear level in the seated position; any deviation produced a very noticeable drop off in the higher frequencies. This ultimately bothered me when approaching the speakers as they were playing, or even reclining in my seat. In retrospect, I would probably go with a good dome tweeter or ribbon with proper lens geometry, over this particular design.   

Perhaps you will have a better experience if you plan to use it as more of a midrange driver.

[Skeeboingen]

That's exactly what I had thought of using it for was midrange, and crossing it over at something like 5000Hz to perhaps a Fountek ribbon. Opinions?
Also, since you have experience with it, how low do you have it crossed over?

~S

[matevana]

I no longer own them, and were using them in a completely different application. They basically served as high frequency reinforcement to a full range driver, crossed over high and shallow with a single cap. The AMT design is very lifelike and added a good deal of sparkle, which is what I was hoping. Didn't really take advantage of their midrange properties, since they were crossed so high.

[JohnR]

I prototyped them as a midrange, crossed at 3 kHz to an Aurum Cantus AST2560. Measurements were good but I didn't spend much time listening as the configuration (low crossover at 1200 IIRC) meant they were working over quite a limited range and my panels had to be a 4-way. Doing a passive crossover at the low end will probably be tricky too. Neo10 is easier to work with, I expect I will find a use for the AMTPROs eventually tho (e.g. an application where I don't care about the vertical dispersion).

[Skeeboingen]

So would NEO 10s be a better choice?  I am also looking at $.  It seems like they are always used in arrays, never singles.

~S

[JohnR]

If you search you will find plenty of uses as a single. Obviously the dispersion falls off much more quickly in the vertical than it does in the horizontal but you can't have everything