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Open Baffle Epiphany!

dfoulk said:
Hi Poultry:)

Turned one around for a portrait. I also need a rear guard from kitties around here, but I have compared a shallow baffle with these and not noticed a terrible
downside to having the sides. I do like those Focal mids though, so glad that I tried them out for size. I guess that I had developed a bias for the larger drivers
over the years, but these 5 inchers are nice. I don't know when Focal stopped making them, but they are solid.
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:thumbsup:
 
To further my education on dipoles I ordered these Heils during their big sale. Don't know yet if I will use them with OB's but time will tell. I know they'll sound nice with the Frugal Horn Mk3's.

heil1_1024x1024@2x.jpg
 
I picked up a Rolls active crossover from Parts Express to try with some of my bi-amped systems. Testing it in the garage with one TPA3116 amp powering the Tekton full range single drivers and another TPA3116 driving the 16" OB woofers.
I'm impressed with the sound and the ease of set up. Unlike other actives the Rolls doesn't impart its own sonic signature that I can hear. I plan to try it with other OB's and tube amps. So far I can recommend it.

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evsentry3 said:
Here is a bit for those that enjoy OB....

Set up a full quad system at CarverFest this year.

Front OB

Front OB

  • Media owner evsentry3
  • Date added
Front speakers of OB quad at CF.

My short line source OB's. TB 1808 stacks for mains and 10" Goldwood dual VC drivers for bass. Sublime Acoustic crossover at 80hz between mains and bass. Mains run on Carver Crimson 275's and bass from older Carver TFM-25.
Rears much the same.

Rear OB

Rear OB

  • Media owner evsentry3
  • Date added
Rear speakers of quad at CF.

Space a little tight but ok. Source from Oppo into a Sony ES series analog multi-channel pre which feeds the crossovers. No eq, no manipulation, just straight analog after it comes out of the Oppo and no high level crossover elements.

Comments from people had the system and the source material well received. Was told it was the system to see and hear here this year. Nice to hear when such nice other systems are present. What really made it was the real deal quad music, mostly from multi-channel SACD. The big hit.....Carpenters! Didn't expect that. Also got to debut some of the Immersion set of Pink Floyd and the quad versions from that!

People are very taken with the super quality of the quad and the presentation of OB. Can't tell you how many commented on the clarity of the OB. But us in the know......know!

EV3
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Curious, does your Crimson 275 have a 15 watt Elcor output transformer hiding under the giant tranny cover?
275 tranny.jpg
 
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Adding tweeters or super tweeters.

Been pondering this lately. Not mounted to the baffle and facing frontward, but rather mounted to a 90* bracket and pointing upwards.

What are the best ways to do this and what are some drivers that work particularly well for this?
 
z-adamson said:
Adding tweeters or super tweeters.

Been pondering this lately. Not mounted to the baffle and facing frontward, but rather mounted to a 90* bracket and pointing upwards.

What are the best ways to do this and what are some drivers that work particularly well for this?
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Curious.... I have a pair of super tweeters and what does pointing them up or Poultry said his were facing backwards?? What does this achieve exactly?
 
The Fuxtor said:
Curious.... I have a pair of super tweeters and what does pointing them up or Poultry said his were facing backwards?? What does this achieve exactly?
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Tweeters are not dipole typically and with an ob you want sound to be directed from the baffle foreword AND from the baffle backward. When pointed up, you get just that. Never heard of pointing them back, but I have heard of pointing one foreward and another back (2 tweeters per side).
 
I discussed OB tweeter location with Danny of GR Research some years ago and his take was if using a single monopole ( closed back model ) it should face to the rear. When I tried this I didn't care for the weak output but when I balanced if off with a second front firing tweeter wired out of phase I liked the results enough to make it permanent. Linkwitz used front and rear firing tweeters in his Model LX521. Other than resting a Realistic pod super tweeter on its back I've not tried much in the way of an up firing tweeter. From all I've read it has merits and is worth trying. The B&G Neo 3 tweeters come as monopoles but the back cup is removable so they can function as dipoles and fire in both directions.

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Talking full range speakers

What does anyone think of the EV Wolverine LS-12? I've been gathering speakers, and this is one In considering trying.
 
DesertRatt said:
Talking full range speakers

What does anyone think of the EV Wolverine LS-12? I've been gathering speakers, and this is one In considering trying.
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Good choice. With a Qts of 1.7 the LS-12 should make decent bass in free air. A Qts of .75 would be about the lowest that's acceptable for a single OB driver without a helper woofer. The higher the better and 1.7 is very good. A low Qts driver designed for a box enclosure will usually sound thin in an open baffle.
 
Poultrygeist said:
I discussed OB tweeter location with Danny of GR Research some years ago and his take was if using a single monopole ( closed back model ) it should face to the rear. When I tried this I didn't care for the weak output but when I balanced if off with a second front firing tweeter wired out of phase I liked the results enough to make it permanent. Linkwitz used front and rear firing tweeters in his Model LX521. Other than resting a Realistic pod super tweeter on its back I've not tried much in the way of an up firing tweeter. From all I've read it has merits and is worth trying. The B&G Neo 3 tweeters come as monopoles but the back cup is removable so they can function as dipoles and fire in both directions.

View attachment 2716966
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So I see 2 tweeters, 1 full ranger 12" driver, and likely an eminence alpha 15 below.

So, are you quad-amping? Are you running the tweeters in parallel with the full range driver?
 
Poultrygeist said:
Good choice. With a Qts of 1.7 the LS-12 should make decent bass in free air. A Qts of .75 would be about the lowest that's acceptable for a single OB driver without a helper woofer. The higher the better and 1.7 is very good. A low Qts driver designed for a box enclosure will usually sound thin in an open baffle.
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I went ahead and bought them. I now have the following drivers:
(2) Electro-Voice SB-12
(2) Electro-Voice Wolverine LS-12
(2) CTS 12" Alnico
(2) Zenith 10" alnico 49CZ1043
(2) Eminence 15A woofers
(2) 2" paper tweeters

And I have the miniDSP HD.

I think that gives me a lot of opportunities to try different things. I have designed by open baffle system on vertical rails such that I can plop various motorboards on easily to facilitate trying different drivers. There is a woofer panel, a full range panel, and a smaller panel for any L-pads, or controls or other parts.

I'll be making sawdust this weekend!
 
z-adamson said:
So I see 2 tweeters, 1 full ranger 12" driver, and likely an eminence alpha 15 below.

So, are you quad-amping? Are you running the tweeters in parallel with the full range driver?
Click to expand...

I'm bi-amping with a SET amp driving the Zenith full range drivers and tweeters in parallel ( caps on the tweeters ) plus a single 100 watt plate amp powering the two Alpha 15a's. The tweeters take very little power and present an insignificant load.
 
Poultrygeist said:
I'm bi-amping with a SET amp driving the Zenith full range drivers and tweeters in parallel ( caps on the tweeters ) plus a single 100 watt plate amp powering the two Alpha 15a's. The tweeters take very little power and present an insignificant load.
Click to expand...
How important is the physical proximity of the tweeter to the full range driver? Lets say they are a few inches apart? Lets say they are a few feet apart?
 
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