• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

My latest affordable 3 way Open Baffles

Poultrygeist

Poultrygeist

Lunatic Member
These are Eminence Beta 12LTA with super tweeters over H-frame Eminence Alphas ( thank you Parts Express ). The 98 db 12 inch Betas offer huge sound compared to smaller full rangers and the level of detail surprised me.

picture.php
 
Register to hide this ad
The top baffles are MDF covered with textured wall paper and then painted. I doubt I have $300 in this build. Right now it's putting my other speakers to shame.
 
I went with Peavey super tweeters as they were recommended as a good match for the Betas.

Eminence of Kentucky, the world's largest speaker company, supplies drivers for Zu, Tekton, Hawthorne and many others.
 
I'd be thinking about integrating some of the better Fostex horns with those (just sayin')... :-)

The Beta-12LT is a nice driver; long ago the late John Wyckoff made had a nice design based on that driver with a quasi-coaxial tweeter.
 
Googling "thorsten Loesch afterburner project" will bring up his take on the LT12; his recommendations for cone treatment and notch filtering might be useful.
 
mhardy6647 said:
I'd be thinking about integrating some of the better Fostex horns with those (just sayin')... :-)

The Beta-12LT is a nice driver; long ago the late John Wyckoff made had a nice design based on that driver with a quasi-coaxial tweeter.
Click to expand...

Did you ever get to hear those after they were broken in? Brand new, they didn't make such a great impression, IIRC.
 
heh, that's right - we both heard them together, didn't we?! That's getting to be quite a few years ago...

I would be a bit nicer to them than that - they were quite dark but they definitely had a "refinement" that I thought was impressive given how inexpensive the drivers were. I also remember that James was having a phasing problem when we started listening to them. My recollection was that they were promising... but I ahem cannot actually remember if I ever heard them again...

ahhh, in a sort-of reverse senior moment, I do remember the name of the company - Hammer Dynamics.
 
I didn't mean to come off too negative - just that they weren't broken in. There were probably placement issues, too. I'm genuinely curious about them ... as I think the "efficient speakers have a lot of advantages" part of my brain is kicking in again.
 
I'm driving the Betas with Bottlehead 2a3 Paramours and the Alphas with Dayton ss mono blocks which have active XO controls. I'm still experimenting with a 2uf cap for the tweeters but will probably go to a 1uf as I don't want much sizzle on the top. I plan to try the tweeters with their own t-amp.

My smaller Fostexs come off thin in comparison. The Hammers don't use two 15 inch woofers for bass support and I believe they use passive XOer's.
 
Rear view of Tang Bands and Beta 12LTA

The only mods I'll do on the Betas are dust cap ectomy with replacement phase plugs.

picture.php
 
I've pulled the Beta 12LTA to remove the dust caps and add phase plugs. A lazy susan allows me to spin the Beta while I hold the blade still.

picture.php
 
Here are some wooden Easter eggs I picked up a local craft store. They fit the Betas perfectly. I painted them and screwed wood screws into their flat base so they can be magnetically held in place.

picture.php
 
I have tri-amped these 3 ways using a 2a3 SET for the Betas, a T-amp for the super tweets and two mono-block solid state amps for the Alpha H-frames. the Betas run full range with nothing in the signal path and the tweeters use a 1uf cap filter. The mono-blocks driving the Alphas have built in crossovers which I set at 80hz. The phase plugs did wonders in smoothing out the highs.

I wish you guys could hear these puppies as I never would have imagined they could sound this good.

picture.php
 
Poultrygeist, at some point in the near future I'll be blowing up your PM inbox as I've been chompin at the bit to build some OB's or dipoles. From what I've seen here on AK you just keep raising your own personal bar with your experiments. I met MJ King about a month ago at Lone Star Audio fest and got to hear the H-Frames with Fostex drivers. I thought they sounded pretty damn good even though the hotel room he was in allowed a less than ideal set-up. So you said you had about $300 in them....that's all six drivers, correct?

- Michael
 
You must log in or register to reply here.
Back
Top Bottom