[EDS_]

Has anyone heard a single driver open baffle speaker that sounded good. I'd like to move my Cary SLI-80 (tube integrated-triode, UL selectable) into a home office system. In the office I listen at low to moderately low volumes, generally listening to old jazz, simple blues, and light classical. I'm thinking an open baffle "x-overless" system might be fun to try.

1. Space is not much of an issue
2. Speakers could be positioned nearfield or not
3. I have subwoffers if needed
4. Might use a squeezebox or an IPod or an old Rega Planet as the source
5. I'm scared of tiny drivers


All input appreciated....

[mcgsxr]

I am sure that plenty of folks will point you in the direction of the 100+ page thread in the Red Wine Audio Circle, regarding various implementations of the Visaton b200 on OB... well worth a read!

http://www.audiocircle.com/index.php?topic=19253.0

I have been using mine for 1.5 years now, and really like how they work...

[Kevin Haskins]

It all depends on what your priorities are...    Single drivers have some problems and benefits.

In the plus column:

#1.   They should be cheap!  No crossover and the cost of materials is the same as it is for a traditional driver.   Unfortunately that often isn't the case as they are a niche product and the price is driven up by that market reality.   In commercial products designing something as a single driver is considered the cheapest route.   

#2.  They are easy to design with!     No crossover!

#3.  They are easy to build... especially on an open baffle!   

#4.   Many of the Fostex/Lowther type of drivers are easy loads.   

#5.   They are fun!   Due to the ease of building, experimenting etc.. you don't have to have a complex measurement system and a degree in acoustics to build one.

Negatives:

#1.  They are expensive!  (see #1 above)

#2.  They are difficult to design with to get good results!   By this I mean low distortion, even power response, smooth frequency response and wide bandwidth.   They are often no more than a large format midrange with a few shorting rings to lower the high frequency inductance and provide extended high frequency response on-axis.   There are very few that provide any real excursion capability and would make them good low frequency transducers.    On an open baffle it is even worse because you are expecting them to perform as dipoles which if used low require the ability to move a lot of air.   For open baffle use I wouldn't look at anything smaller than 6" and I'd prefer 8" or 10" drivers to give you the extra Sd.   You will need a subwoofer that will run relatively high depending upon the size of the baffle and the driver you choose.  A sealed pro-audio driver designed for 2-way use that doesn't have any break-up nodes up higher will ease the transition.   

#3. Lots of experimentation required.

#4.  Your always, no matter what going to be missing out on some bandwidth.   Only you can decide if that is acceptable or not.   

[mcgsxr]

There are also many folks quite happy with (uh-oh, off topic warning...) these coax's.

http://www.hawthorneaudio.com/index.html

I will stick with my b200 OB, with subs, in spite of the very valid points raised by Kevin - in my room, the compromises are ones I am willing to enjoy etc.

[nathanm]

I have no experience with open baffles (although that's about the only DIY speaker project I think I could actually finish!) but the nice thing about small drivers is that they don't beam like the big ones.  Listen to the crazy head-stabbing peaks coming off a 12" guitar speaker for instance.  To me coaxials make more sense at larger diameters.  Based on most of your listening conditions I'd recommend the Norh 3.0s which use the TANG BAND W4-616S driver (I think). 

I know they don't meet the OB criteria, but these little things are impressive in the bass reflex configuration.  It would seem that to get comparable low end from an open baffle you're looking at a huge sheet and larger diameter drivers but then you've got the nasty beaming going on.  I have been strongly disappointed with the 8" Fostex drivers I have heard.  They sounded very mechnical, papery and artificial and that was even after I beat the hell out of them with burn-in tones for hours on end.   Definitely not the sound for me.  With the Tang Bands you'll be compromising the bass and treble and power handling but there's a rightness to the tonality that makes them very easy to listen to.  It's bandwidth-limited without giving the impression of thinness and weakness IMO.  "Forgiving" perhaps?  I listen to them nearfield but in a 9' triangle they really have amazing imaging due to the small size.  The new black marble ones are very nice looking too. (finally, four legs!)

[Bemopti123]

Check out my gallery for a 3-4 hour project that was based on JE labs design OB suggestion.  I paid just about $60 for the plywood cut into pieces and the rest was labor.  A jig saw and a drill, that is all you need. 

The choice of driver can be had between $100 a pair to $500, the limitation of this set up is the driver itself.  I have mine coupled with a subwoofer and so far, the experiment has given me satisfactory results, without really twitching to upgrade to anything else.  Even without the subwoofer, it gives a decent low presentation.  While it the Altec 755Es I am using might not give me the ultimate in slamm or bass presentation, it does provide enough "meat" in the low frequencies that, if I did not have the sub, would not even thought about adding.  BTW, not that I have much power available in the taps of my battery powered op-chip amp, weighting in at 10 watts on 8 ohms. 

I am quite happy with the presentation I get.  Smooth, without being syroupy.  If you decide to being collecting fullrange drivers, then, you can always experiment using the same baffle for a different presentation each and everytime. 

link to gallery:  http://www.audiocircle.com/index.php?action=gallery;area=browse;album=171

[JLM]

Scared of small drivers??  Is there a story here?  Were you traumatized as a youth by a small speaker?   

These are my opinions, not shared by all:

1. Even the 15 inch Hawthorne Iris coax lacks bass needed to fully reproduce most musical forms (and wouldn't touch electronica or large organ stuff).  Why do you think speaker cabinets were invented anyway?  Asking a single driver to do bass without a box is asking for your cake and eating it too.

2. The presentation is less pin-point, more "natural".

3. Bass response goes deeper as the baffle size increases, but so do the reflections from the opposite speaker.

4. Imaging improves as you provide more open space behind and sit farther away.  A minimum 15 ft x 25 ft room should be provided.

5. The B200 is possibly the best, half-way affordable, single driver for O.B.  The Fostex F200A is another 8 inch driver that goes deeper, but costs more and is less efficient.  Neither have whizzer cones, so they do beam above 4,000 Hz (not a problem if you can stay near the sweet spot).  BTW this Fostex is nothing like the typical "full range" drivers they sell.

6. Kevin is right, most "full range" drivers are better termed "extended range" and nearly all would benefit from a woofer/tweeter to cover the top two and bettom two octaves.

7. The essence of music is the mid-range and all to often marketers focus on the frequency/spl extremes.

8. Most SET/single driver purists I know have learned to live without deep bass, so opinions vary on how successful open baffles and/or single driver designs are.

9. I disagree with Kevin about the expense of the drivers.  Building a driver to cover 8 or 9 octaves should be harder (and cost more) than "speciality" driver (woofer, midrange, tweeter).  Considering that with a single driver you by default have an "active" speaker (with all it's advantages) it's much cheaper than a two or three way active design that requires two or three times as many amplifiers and active crossovers.

[GHM]

Nice Paul!!!  Wish I lived closer so I could hear them. Great pics!

[meilankev]

I'm a little confused here - I thought Infinite Baffle was a type of subwoofer (IB-Sub) that is built into the wall or ceiling in essence making the entire listening room a "subwoofer enclosure".  I wasn't aware it was commonly applied to other speaker types.

Kevin

[opnly bafld]

Kevin,
In EDS's first sentence he refered to open baffle.
I think everybody assumed he made a mistake in the subject line.

JLM,
I would be nice if you would lose #8, everybody I know using OB speakers, likes low bass, wants low bass, and are using various means to get low bass.
Nobody around here has learned to live without anything, we all want more.

Lin

[JLM]

Lin,

I fixed it up a bit for you.  Like I said, they're my opinions and not everyone agrees with them.


Kevin,

Good point.  The best application for I.B. is for subwoofers.  Actually a few have tried I.B. for full/extended range use.  Any wall mounted speaker that has at least 4 - 10 times the driver's Vas value is in effect running in I.B. mode.  Obviously depth of soundstage will suffer, but it could be a real space saver.

[Stempy]

It all depends on what your priorities are...    Single drivers have some problems and benefits.

In the plus column:

#1.   They should be cheap!  No crossover and the cost of materials is the same as it is for a traditional driver.   Unfortunately that often isn't the case as they are a niche product and the price is driven up by that market reality.   In commercial products designing something as a single driver is considered the cheapest route.   

#2.  They are easy to design with!     No crossover!

#3.  They are easy to build... especially on an open baffle!   

#4.   Many of the Fostex/Lowther type of drivers are easy loads.   

#5.   They are fun!   Due to the ease of building, experimenting etc.. you don't have to have a complex measurement system and a degree in acoustics to build one.

Negatives:

#1.  They are expensive!  (see #1 above)

#2.  They are difficult to design with to get good results!   By this I mean low distortion, even power response, smooth frequency response and wide bandwidth.   They are often no more than a large format midrange with a few shorting rings to lower the high frequency inductance and provide extended high frequency response on-axis.   There are very few that provide any real excursion capability and would make them good low frequency transducers.    On an open baffle it is even worse because you are expecting them to perform as dipoles which if used low require the ability to move a lot of air.   For open baffle use I wouldn't look at anything smaller than 6" and I'd prefer 8" or 10" drivers to give you the extra Sd.   You will need a subwoofer that will run relatively high depending upon the size of the baffle and the driver you choose.  A sealed pro-audio driver designed for 2-way use that doesn't have any break-up nodes up higher will ease the transition.   

#3. Lots of experimentation required.

#4.  Your always, no matter what going to be missing out on some bandwidth.   Only you can decide if that is acceptable or not.   

Zu's mini method and method fit the bill well