Can someone guide me as to what Single driver ??

Darkmoebius: I would not doubt that the Hammer Dynamics system works reasonably well, as i've used the same basic 12" Eminence driver in several different yet similar PA installations. I've made mention of this Eminence driver a few times when talking about full range drivers here on Agon, but nobody has ever asked for specifics on it.

I've got four of these Eminence drivers in my basement right now. They are in partially finished PA cabs that i'm building for a local band. I'm running two of the Eminence 12's per cabinet full range and bringing in an Eminence horn tweeter at 6 dB's / octave at 11 KHz. The shallow slope allows the tweeter and full range drivers to blend right at the point where the larger full ranges are starting to take a nose dive. It also negates the losses involved with a passive crossover on the full-range drivers, improving sensitivity.

We've run similar cab's as mains in small clubs and electronically crossed them with subs below them when more volume and bottom end is needed. They are versatile enough as designed, but the added wallop of the extra woofer area and electronically crossing the full-ranges really adds quite a bit of punch.

Thanks for the links to the "Super-12 mods", as i'm sure that i'll check that out very soon. Sean
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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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Elvis: I've just been watching the audio detectives and learning from them, their discoveries and their mistakes.

Most everything that i've ever learned and / or shared here ( or in other audio forums ) is an accumulation of information that i learned from others that i've put together over the years. As such, i could have overlooked some mods as my detective skills are lacking. That is, i might have missed some other pertinent info that others have found to be both important and useful. I am not omnipotent and can't read / see / do / be everything everywhere at one time.

Obviously, I don't know anything that someone else hasn't already discovered ten times over. That's why i try to take the time to share what i do know, so that others can learn just as i did. While i might think that i've discovered something new, because it is "new" to my level of understanding, further research almost always confirms that many others have already been down that path many times over.

As such, i am proud of what i know. Having said that, i'll not take credit for something that i didn't do. NOTHING that i've ever shared here isn't already common knowledge to those that deeply care about such things.

Darkmoebius: I knew that the Hammer driver is a custom build , but i also knew that it was based on the stock Beta 12LTA. I didn't know the exact differences between the drivers though, so thanks for sharing that info. My brother was looking into these drivers for use with a low powered tube amp when i had to remind him that i've been using these for a couple of years now.

As far as the Zobel goes, i think that the resistor is a bit low in value, but i'm sure that it is better than nothing as far as "hi-fi" linearity goes. I'm using these for live sound reinforcement, where ANY form of increase in sensitivity is considered a good thing. Even if it is slightly less linear, there's always a rack full of effects and EQ to deal with problems like that : )

As you mentioned here, i'm also using a very sensitive horn tweeter. It is quite a bit hotter in output than the paralleled Beta's, but as mentioned, i'm crossing it quite high and there are always EQ's available. Having the higher output from the driver simply means less power draw from the amp. This not only reduces thermal strain on the amp, but also the driver itself. Sean
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This Monacor SP-30PATC speaker may be of interest to some folks out there. Looks pretty similar to the aforementioned Eminence Beta 12LTA, but with higher sensitivity and slightly flatter response. Don't know how they work in the real world, but according to spec's, it doesn't look bad. Sean
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