Can someone guide me as to what Single driver ??

Sean,

Which Eminence driver are you talking about? Not that I have a project for it right around the corner, but if you like it that much then I want it in my bag of tricks.

Thanks,

Duke

Duke, for an inexpensive driver, the Eminence Beta 12LTA offers pretty wide bandwidth and high sensitivity. Eminence has recently revamped their measuring techniques, so some of the spec's may be different than what is posted on PE's website. Lot of basic mods that can be done to improve performance without a lot of cost. Still want to check out the list of mods for the Hammer Dynamics that Darkmoebius listed above though, as maybe others have caught some things that i haven't.

Other than that, one can build a complex crossover with Zobel's to flatten the rising impedance, but i've never bothered. Running a pair of these nets you 99+ dB's @ 1 watt without ever dipping below 4 ohms anywhere in the band. Easy load, wide bandwidth and high efficiency for not that much money. Sean
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Still want to check out the list of mods for the Hammer Dynamics that Darkmoebius listed above though, as maybe others have caught some things that i haven't

Oh no, tell me it ain't so!

"Maybe" somebody thought of something you didn't?

A little full of ourselves don't you think?

Hi Sean,

Glad to hear you put these great Emminence drivers to good use. They are a true miracle value when properly used.

I should point out that there are some significant construction differences between the commercially available 12LTx driver and (the late)John Wyckoff's custom made Emminence Super-12.

To quote JW from the Super-12 mods page I linked above:

John Wyckoff's description of the Super 12 (compared to the Eminence Beta-12LT)

Cone composition: Beta-12LT is conventional Kraft type. Super 12 is slightly heavier (different mix of fibers).

Voice coil: Super 12 has smaller gauge wire with a Nomex former. (I dropped the Kapton former after the first ten samples.) Beta-12LT uses Kapton former which is not quite as neutral in the mids. Super 12 coil is slightly lighter bringing moving mass to about the same. Super 12 uses one shorted voice coil turn to reduce inductance and improve high frequency response.

Motor: Super 12 has a soft-iron polepiece to improve BL. Beta-12LT has low carbon steel. Super 12 has shorting ring at the base of the polepiece and is capped with an aluminum shorting ring (also called Faraday ring).

Spider and suspension: Super 12 spider is woven Kapton fiber and is slightly softer. The suspension on the Super 12 is doped to be slightly stiffer.

Glue: Super 12 uses a lower-mass, harder formulation, and less of it. Improves high frequency response.

As to how big a sonic difference that all makes, i have no idea. I've never heard the regular Beta 12LT.

Other than that, one can build a complex crossover with Zobel's to flatten the rising impedance, but i've never bothered.

The Super-12's use a very simple series 12uf cap + 7 ohm resister [url=]Zobel network[/url](x-over diagram) on the 12".

One of the big changes was switching from the stock Audax tweeter to the more sensitive horn Fostex FT-17.

>>A little full of ourselves don't you think?<<

Far better that than what you're full of.