open baffle speaker question


i see lots of designs for the diyer. i have never heard a pair of these [except magnepans] and need some advice if this is a project that would be worth attempting. the costs are minimal evidently but would like to hear from someone with experience about the sound quality of this design using quality drivers etc. are super tweeters needed? thanks
hotmailjbc
Hi Hotmailjbc,

you have two very good recommendations here, the Orion and several designs by GR Research. Nice thing about many of the GR designs is that they incorporate a 12" sub into the cabinet, but the separate sub is always an option. These may or may not be a challenging build depending on one's abilities. And there are simpler approaches if you just want to experiment. Or, another option is to contact one of the builders of these speakers and contract a pair.

The open baffle designs can give you presentation close to the electrostatic/planar. They image very well, sometimes in circumstances that would destroy the presentation of most other designs. They can also have dynamics that approach that of horns. OB designs are usually pretty efficient also. Most speakers of this design don't give the "audiophile" presentation many folks get wobbly in the knees over, but that is a good thing IMO.

Personally I would avoid single driver, full-range designs. (Except again for experimentation.) Unless one can afford really expensive FR drivers there will be response compromises. I know for myself that would just lead to my adding drivers and more xover parts to fill in the frequencies.

I am very familiar with the OB-7 from GR Research since I can hear these from my neighbor's house, 100 yards away. ;-) I arranged the purchase of these speakers for this neighbor who was buying solely on my recommendation of Danny's work at GR. Long story short, my neighbor has been rocking the neighborhood for three years now, and still raves about the OB-7s every time I visit. He says he gets compliments all the time from people who stop what they are doing for a minute or so to listen.
Lplayer wrote: they are technically "planar" speakers

What does this refer to?

Kal
Not to pick nits, but I would say planars and OB are both dipolar designs. I like to keep the distinction based on different driver technology, but that's just me. ;-)
'Open baffle' usually refers to a cone speaker mounted on a baffle with an open back. Quite often this means there are no sides to be baffle either but that sort of depends on who you talk to.

Technically speaking all planar speakers are open baffle by definition. However the term usually does not refer to them.

Open baffle speakers can have multiple drivers. The old Carver Amazing is an example. But most open baffle setups you will see usually use a 'full range' driver of some sort, a Lowther, PHY or perhaps a Fostex.

I saw a very convincing setup in Nelson Pass' room at RMAF about 3 years ago. He showed full-range driver that looked like a Lowther, and there was a second driver mounted on the baffle that was assisting with the bass. The speaker had very convincing bass and overall his system was quite musical. I seem to recall that he mentioned something about the dynamic range being limited in some way but don't quote me on that.