Open Baffle Epiphany!

I listen mostly in the 70's and 80's and haven't tried high volume but I'm sure they'd play loud enough if pushed hard but their power band is limited.

OB's are not for headbangers and at 100 dbs you'll be hearing baffle vibration unless they're concrete. Folks go to great lengths to curb resonance with thick sand filled baffles or layers of composite held together with exotic sound absorbing green glues. Since I don't care for loud music I've always used basic 3/4 plywood or MDF. At the levels I listen at resonance is not audible.

The Zeniths are from the 1950's and were designed to be powered by flea watt tube amps. That was the only amplification available then. I doubt they would be a good match for a powerful solid state amp.

I would definitely go with the woofers first and power them separately from the Zeniths ( bi-amp ). The tweeters that came in my Zenith console were not very good and I trashed them.
And which crossover you have with Zenith baffle??
Is this crossover for all 15 drivers or only for Eminence Alpha15a?? Because I have bought Allo volt+d and I think that I will buy the upgrade woofer of Eminence, Pure Audio project a15neo finally...
 
The Zeniths run full range with nothing in their signal path. I use this electronic crossover ( Ashly XR-1001 ) but only on the Alpha 15A woofers. A cheaper Behringer active can work as well. You will probably need XLR to RCA cables or adaptors 1/4 or XLR with most pro electronic crossovers. You can also go with a DSP unit for the crossover but personally I like the ability to make adjustments on the fly as these are analog not digital and don't require PC set up. A good option for a fixed crossover are the Harrison Labs Fmods of different frequencies which like an active install upstream of the woofer amp. Lastly would be a plate amp for the woofers which have a built in crossover.

xr1001.jpg
 
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I use this $79 Behringer 2310 active with another OB system and for woofer duty it works just as well as the Ashly. It has a separate connection and controls for a sub woofer that I use with some diy bucket subs.

s-l1000.jpg
 
I use this $79 Behringer 2310 active with another OB system and for woofer duty it works just as well as the Ashly. It has a separate connection and controls for a sub woofer that I use with some diy bucket subs.

s-l1000.jpg
Behringer or Ashly or Harrison labs has better sound??
All these with Pure audio Project a15neo?? It is similar with Eminence Alpha15a but surely better. Please check this:
http://www.pureaudioproject.com/product/15inch-open-baffle-bass-woofers/
Thank you Poultry!!! You are connoisseur of smart solutions of economic hi end audio !!!
 
I could not hear any difference between Behringer and Ashly when used with LF woofers. I have no experience with Fmods but others like them. Pros: cheaper Cons: fixed frequency
 
I could not hear any difference between Behringer and Ashly when used with LF woofers. I have no experience with Fmods but others like them. Pros: cheaper Cons: fixed frequency
For fmods some they tell that it is good only for low volumes. Not for loud. Is the same for Berhinger that you have this???
 
For fmods some they tell that it is good only for low volumes. Not for loud. Is the same for Berhinger that you have this???

In both cases they filter the high frequencies and allow the low frequencies to pass. Loudness is a different issue.
 
Hi Paul
I am slowly getting the parts together for my OB project.
I have collected a variaty of vintage drivers, but I think I will start with the 15” Zenit’s.
I guess I need something for the high end extension, and I was thinking of either the ASD 1001 with an Dayton Audio H08RW 8" Round Waveguide or the B&G Neo 3 PDRW-2.
Which one do you think will suit the Zenit’s best?
The price will be almost the same.
The ASD 1001 is 104db, but the Neo 3 is only 90db.
Maybe the Neo 8 is better with its 93db.
 
The ASD with it's 104dbs is better because a tweeter should be more efficient that the main driver it supports.

You can pad a tweeter down for lower output but you can't increase it's output if it's already less efficient.

I would not buy any tweeter until you've spend time with the Zeniths using woofer support. If the Zeniths don't play high enough for your tastes then buy the ASD's.

If using a single ASD I'd position it so you could try it firing backwards as well as forward. Mine was a little too hot firing forward ( using a 1.5uF cap ) until I added the

rear firing Realistic super tweeters to the mix.
 
DSC_0622.JPG ^It does not. I use a DBX active, cross the FR @ 53Hz 12dbBW. Let the woofers run. They cross @ 160Hz when measured.
 
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OK, now that everybody has whipped out their checkbook and ordered a set of very on-sale Heil AMT's (What?! You haven't got yours yet? Hurry up, Mon!) How can these be used in the open baffle scene? Since these are true dipoles, it seems they would fit into an OB platform somehow. I keep seeing a D'Appolito arrangement with the Heil mounted in a cutout in the baffle.
But how will the AMT react to being in the baffle itself? Would it take some of that precious airiness away? I have seen one mounted inside a baffle in a monkey-coffin from ESS no less, but that's a long story with no evidence to back it up. The backside fired directly into a dampened box..., oh, the tragedy.
I'm going to experiment with this idea, even if it means just stuffing them into a piece of cardboard. Any discussion about this idea or plans from the new rash of Heil owners would be welcome.

Hey Poultry, I can't see that last image you posted.
 
I'm so tempted by the Heils but don't have a current project for them. Should I get a pair I'd add a tweeter shelf to place them above rather than integrated within the baffle.

The image of the Betsy Omega's was lifted from AC which is probably not kosher.

PB300005.jpg
 
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