Poultrygeist
Lunatic Member
If you want to taste a bit of the OB experience take your best box speakers outside and listen to them in near field with your back against the house. The openness and airy sensation you get from OB's is similar.
Open Baffle Epiphany!
- Thread starter cptnCanada
- Start date
BadassBob
Digitally rendered
When I first got my EV's a few years ago, I ran them without cabs/baffle's for a week until I tracked some down. They sounded pretty good in free space, just a little shy in the bass. I can't wait to get them mounted on a sheet of plywood with a helper woofer :yes:
dodog
Addicted Member
That thread is mesmerizing. They state:
I dig that they can use the small box, cut a section of Rubbermaid wall-shelf for the baffle (that looks, from the pics, to be a near-perfect match) and fit a nice 10" woofer. A few follow-up questions.
1) What are some decent 10" woofers to use for this project?
2) Is it common to drive the H-frames with a separate amp or does each woofer get driven off it's own/modded plate amp from a sub-woofer? What type of power do you need to get the woofers going? Would, say, 25W of a nice class-A be enough to drive two H-frame 10" woofers or would you need a lot more power?
3) Is it more common to have the full-range driver get the full-range, but also send a split of that signal to the LF/H-frames? Or, is it better to have a highpass filter, feed that to the fullrange driver and send the lower frequencies to the H-frames? Given either of these scenarios, how would this feed into question #2 (power requirements for both fullrange and H-frame woofers)?
4) Is it common to physically attach the open baffle board to the H-frame box or is it sufficient to have an L-shaped stand that merely sits on top? Would the H-frames vibrate too much that you'd need them to be couple with screws? If you could set the open baffle on top, has anyone played with placement of the woofer vs. the open baffles? Can you point them in different directions or would that be a no-no?
Poultrygeist
Lunatic Member
1 -MCM and Dayton woofers can't recall the models ( look for qts .7 and above )
2 -One plate amp is enough to drive two woofers. The Yungs on PE are inexpensive and if you hook 8 ohm speakers in parallel to get 4 ohms you can get max power from most plates. I drive 4 Alphas with a 300 watt plate hooked up this way but 200 would be plenty with 90 db woofers.
3- Unless you want to get into electronic crossovers you can run the full range speakers straight off the flea amp. Split the signal from your CDP/source with Y cables and feed both the flea amp and plate amp. The plate amp will crossover the bass. If you have a preamp with two outputs you can connect one to the flea amp and the other to the plate amp. If you don't want to buy a plate amp and have any regular amp of decent power you can use the F-Mods to filter the highs from the woofers. F-mods are sold on ebay and PE.
4- You don't need to attach them ( mine are like an inverted T and they just rest on top ) as you may want to try different drivers. I glued and screwed my H-frames together and they don't vibrate. I used the Kreg pocket hole jig to join everything. Check it out on Youtube it's great! It's fun to move them around and some folks like them toed in and others like to listen off axis.
Hope this helps. It may sound challenging but the end result is more than worth the effort.
2 -One plate amp is enough to drive two woofers. The Yungs on PE are inexpensive and if you hook 8 ohm speakers in parallel to get 4 ohms you can get max power from most plates. I drive 4 Alphas with a 300 watt plate hooked up this way but 200 would be plenty with 90 db woofers.
3- Unless you want to get into electronic crossovers you can run the full range speakers straight off the flea amp. Split the signal from your CDP/source with Y cables and feed both the flea amp and plate amp. The plate amp will crossover the bass. If you have a preamp with two outputs you can connect one to the flea amp and the other to the plate amp. If you don't want to buy a plate amp and have any regular amp of decent power you can use the F-Mods to filter the highs from the woofers. F-mods are sold on ebay and PE.
4- You don't need to attach them ( mine are like an inverted T and they just rest on top ) as you may want to try different drivers. I glued and screwed my H-frames together and they don't vibrate. I used the Kreg pocket hole jig to join everything. Check it out on Youtube it's great! It's fun to move them around and some folks like them toed in and others like to listen off axis.
Hope this helps. It may sound challenging but the end result is more than worth the effort.
So...what should I be looking to do with my Coral Beta 8 drivers? They're in traditional cabinets, only mine aren't ported, but have a passive radiator in each. I do have dish pack cardboard though, so I guess it's time to experiment. Any baffle size recommendations? Been trying to read up on it but still haven't gotten it all down.
Poultrygeist
Lunatic Member
This guy likes his Corals in the folding wings. ( dang it I lost the link ) The Corals have a wonderful rep and I want a pair. If you know what you want build a real baffle. I don't mind taking the guess work out of it and going with someone else's proven design.
No matter what FR driver you use it will only get better with the pro woofers.
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Poultrygeist
Lunatic Member
poultry
maybe you could do a sticky on OB designs; might help w/ all these questions
maybe you could do a sticky on OB designs; might help w/ all these questions
Last night I extended the width of my baffles using rigid fiberglass panels.
My baffles are now about 4' wide and 4' high with the drivers at ear level.
The speakers now go very deep.
No measurements (no mike...)
I'm a happy camper.
Just keeps getting better.
I'm still playing with baffle size and design.
Am now thinking about a modular design for extending the baffle width rather than using the hinged approach which seems so popular.
This would allow one to build the very wide baffles required for deep bass and not have the speakers occupy the entire room when not in use.
I'm using vintage University 312 Series 200 diffaxials.
Art
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Poultrygeist
Lunatic Member
Gosh I feel like I'm just scratching the surface and there are many here that know a lot more about OB than I do.
maybe just the basics:
single driver (JE labs, winged baffles, etc)
multi driver
crossover
active
passive
types of drivers
build threads
links/resources
single driver (JE labs, winged baffles, etc)
multi driver
crossover
active
passive
types of drivers
build threads
links/resources
Poultrygeist
Lunatic Member
That's great. I felt the same way when I built the big folding wing Betsy's. I thought I had decent bass and was satisfied or at least thought I was satisfied.
If I hadn't discovered OB pro woofers I'd still be happy listening to the folding wings. But the difference is night and day. Wait till opa1 gives us a report on his Alpha H-frames. He's already loving the Wolverine tops and that's just half the project.
I suppose it's a matter of preference and taste in music as well.
It is easy to lose sight of all the really good attributes of open baffle speakers in the quest for more bass.
Seeing as adequate bass is fairly easily achieved this preoccupation might indicate to some that open baffle sound is problematic and requires a concerted effort to sound great.
And we know that just isn't true.
If one hopes to get sufficient bass from an 8" driver I can see where this might be an uphill battle and resorting to a helper woofer is an entirely reasonable course of action.
However I have a 3 way point source speaker with a 12" woofer that is capable of 25 hz.
With a wide enough baffle to minimize baffle loss getting down into that neighborhood seems very possible and it is quite likely that they are there now.
I haven't dug out my lp of E. Power Biggs playing Bach at the Thomaskirche for listening but I'm pretty sure it would be a disappointing experience.
Other than that I can't think of anything in my library that might demand anything much lower than 25 or 30 hz.
Balance, musicality and natural sound are key in any system and these open baffles are pretty close to achieving all three in a very dramatic way (despite my best efforts to screw them up)
E. Power Biggs.
With a name like that how could he have been anything else in life but an organist.
Art
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Poultrygeist
Lunatic Member
Unlike the box sub I was able to integrate the H-frames with the folding wing Betsy's. Perhaps because they're both open baffles or maybe the Velodyne was problematic? But I suspect it's because the H-frames are so speaker friendly. With the Alpha H-frames the bass becomes the music. It's more about bass weight with fast transients than deep bass. Very refined and articulated bass notes but no pressurized room loading or visceral bass. If you like to feel bass open baffles won't deliver but a small box sub added to the mix below 40Hz will.
Here the Betsy's are driven by a APPJ/Miniwatt SET making all of 2.5 wpc while the H-frames are powered by two Dayton amps. There's no crossover on the Betsy's and the crossover on the Daytons control the Alpha's LF.
Here the Betsy's are driven by a APPJ/Miniwatt SET making all of 2.5 wpc while the H-frames are powered by two Dayton amps. There's no crossover on the Betsy's and the crossover on the Daytons control the Alpha's LF.
Poultrygeist
Lunatic Member
If you don't have a preamp with two outputs, connecting these to the CD player/source can feed the amp driving the FR speakers as well as the amp driving the woofers.
Using these splitters, the signal is stronger than from my dual output preamps.
Using these splitters, the signal is stronger than from my dual output preamps.
Hey poultry,
Where do you get those splitters? Look nice!
Where do you get those splitters? Look nice!
tomlinmgt
Lunatic Member
Most say three feet. But for LF content I'd say a little more. When I built the H-frame subs I first tried them about three feet out and was disappointed. I moved them out about another foot and they blossomed. :yes:
Mister Pig
Pigamus Maximus
If you don't have a preamp with two outputs, connecting these to the CD player/source can feed the amp driving the FR speakers as well as the amp driving the woofers.
Using these splitters, the signal is stronger than from my dual output preamps.
When setting up the OB that I have I talked to Mike at Woodsage about repairs to the baffle crack. among other things we talked about speaker set up, and he strongly recommended running the plate amplifiers for the bass drivers off the high pass portion. Some claims you get improved integration doing it this way. My pre-amp has dual RCA outs, with one set being optimized for subwoofers, but I gave it a shot anyways. I did not notice an improvement going into the high pass of the Kiega plate amps, but I did not hear any degradation either. That is the way I plan on running them, as its less expensive and easier to set up. But then again, I need those extra taps to run the Infinity sub that I have plans of integrating into the set up.
Regards
Mister Pig
On Siegfried Linkwitz's site he recommends that speakers be placed at least 3' from reflective surfaces and that a delay of greater than 6 ms of the first reflections is required to perceptually mask them.
My point source speakers are slightly tighter to the sidewalls (out of necessity) than this with about 4' behind them. This changes frequently as I struggle to find the optimal placement in my smallish room.
Open baffles are very room dependent and very sensitive to placement.
Moving them forward and backward you can hear the bass appear and disappear.
Changing the toe-in you can hear the tonality change. More toe-in = greater tonality, less toe-in = less tonality. I'm finding that changing the toe-in by fractions of an inch can make an audible difference.
Some people suggest that closer coupling to side walls benefits your sound in that the walls become an extension of the baffle in the same way that the floor does with drivers that are positioned lower.
There seems to be no end to theories on placement with open baffles.
Experimentation seems to be the key.
It would appear that the rule is free standing out in the room is better.
By at least 3 feet.
But don't feel bound to those measurements.
Other than the research done by luminaries Siegfried Linkwitz and Martin J. King there seems to be little scientific study on dipole speakers.
So hard and fast rules are hard to come by.
It's like the wild wild west out there.
Art
My point source speakers are slightly tighter to the sidewalls (out of necessity) than this with about 4' behind them. This changes frequently as I struggle to find the optimal placement in my smallish room.
Open baffles are very room dependent and very sensitive to placement.
Moving them forward and backward you can hear the bass appear and disappear.
Changing the toe-in you can hear the tonality change. More toe-in = greater tonality, less toe-in = less tonality. I'm finding that changing the toe-in by fractions of an inch can make an audible difference.
Some people suggest that closer coupling to side walls benefits your sound in that the walls become an extension of the baffle in the same way that the floor does with drivers that are positioned lower.
There seems to be no end to theories on placement with open baffles.
Experimentation seems to be the key.
It would appear that the rule is free standing out in the room is better.
By at least 3 feet.
But don't feel bound to those measurements.
Other than the research done by luminaries Siegfried Linkwitz and Martin J. King there seems to be little scientific study on dipole speakers.
So hard and fast rules are hard to come by.
It's like the wild wild west out there.
Art
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