I've been so intrigued by the experiences many of you have had with open baffle speaker designs. The qualities attributed to them seem to be right up my alley in terms of sonic priorities.
I'm wondering, however, if any of you have been satisfied enough, despite the quirks in top and bottom end frequency response, to keep them as your long-term speaker solution?
I'm considering building a set with either the FE-103a Coral holey basket drivers, the older CSS FR-125S, or a pair of the Altec 755E.
I've had a pair of Lowther DX-3 in an admittedly sub-optimal enclosure, and while I found the sound captivating in many ways, I always went back to my Klipsch speakers due to a lack of bass authority with the Lowthers. I wonder if OB is similar in that regard.
How did the OB design pan out for you?
Thanks,
KT
I'm wondering, however, if any of you have been satisfied enough, despite the quirks in top and bottom end frequency response, to keep them as your long-term speaker solution?
I'm considering building a set with either the FE-103a Coral holey basket drivers, the older CSS FR-125S, or a pair of the Altec 755E.
I've had a pair of Lowther DX-3 in an admittedly sub-optimal enclosure, and while I found the sound captivating in many ways, I always went back to my Klipsch speakers due to a lack of bass authority with the Lowthers. I wonder if OB is similar in that regard.
How did the OB design pan out for you?
Thanks,
KT
I've made a few OBs now, ranging from single 10" full rangers to 2 x 15As + an EX3. Sizes have ranged from 5' x 4' to my current MJK 38" x 20" with a single 15A and a 108EZ using a passive crossover. This is now my main speaker, with a pair of Lowther Delphics languishing in the corners.
I don't listen all that loud, and in the relative near field, but I think these domestically acceptable loudspeakers give me more pleasure than any other I've ever owned (and they cost next to nothing in either materials or skills!).
I don't listen all that loud, and in the relative near field, but I think these domestically acceptable loudspeakers give me more pleasure than any other I've ever owned (and they cost next to nothing in either materials or skills!).
KT said:
I am not sure what quirks you are refering to in the OB response. My last two dipole speakers have had more bass output then my previous single driver speakers. Bass output is not a problem if the OB is done right with the correct drivers.
Why not stick with the Lowthers and design an OB system that works with the DX3? It would be great.
I would not waste time with the three older drivers you are considering, either use the Lowthers or buy a new ~4" full range driver and build the OB or dipole system using a more modern driver.
An open baffle system using a full range driver crossed over low to a pro woofer(s) solves a lot of problems that exist in a completely single driver system. The ease of design and construction make it a simple concept to get right. If you think the design through it is hard to screw up compared to a more complicated enclosure/boxed design.
My open baffle w3-871s (needed bass support) was a source of many, many pleasurable hours of low volume listening.
Judging the off axis response and the graphs in stereophile a few months back on the double 12" jamo, the dipole dip will not show up 8-10' away from a dipole in a room.
If you are a full range driver fan, then you are in for a world of headaches if you want higher volumes. Active crossovers sound horrible (especially pa and digital stuff).
I ran mine wide open with an f-mod to some woofers.
Forget impressing somone with slam and volume, that's not what lowthers are about.
I agree with going for the lowthers. But you went back to klipsch for the bass.
MJK is totally right that open baffles need bass support.
Hey an 8" can only move so much air.
Check out mjks design of dual 15" eminence.
But maybe you should build a cheap thing with a good pair of full range drivers you like and already have.
Remember to have the driver offset from the 3 edges for best sound (I.e. 24" wide baffle having the driver 9.2" from left, 14.8" from thr right, and 12" from the top). 1 : 1.31 : 1.618 ratio. But 9.2" from the edge gives an Feq hump at 280hz, then its response drops like a rock. Don't forget that a driver on an open baffle rolls like an infinite baffle. It hits its mass corner (Fs/qts) then rolls off............. Qts .2 lowther with fs of 50hz, the driver will roll off below 250hz regardless if the baffle is 8' wide.
The larger baffle you get, the lower you go (unequalized and not including mass corner), but the less back wall bounce (assuming baffle is 5' from the back wall so you get best sound). Some say huge open baffles have a black hole in the middle (no 10ms low level wall bounce fill).
Or make a foam box to surround the back of the driver and place the open baffle much closer to the front wall. You get clean mids that an OB give you and you can have it a foot from the wall.
Norman
Judging the off axis response and the graphs in stereophile a few months back on the double 12" jamo, the dipole dip will not show up 8-10' away from a dipole in a room.
If you are a full range driver fan, then you are in for a world of headaches if you want higher volumes. Active crossovers sound horrible (especially pa and digital stuff).
I ran mine wide open with an f-mod to some woofers.
Forget impressing somone with slam and volume, that's not what lowthers are about.
I agree with going for the lowthers. But you went back to klipsch for the bass.
MJK is totally right that open baffles need bass support.
Hey an 8" can only move so much air.
Check out mjks design of dual 15" eminence.
But maybe you should build a cheap thing with a good pair of full range drivers you like and already have.
Remember to have the driver offset from the 3 edges for best sound (I.e. 24" wide baffle having the driver 9.2" from left, 14.8" from thr right, and 12" from the top). 1 : 1.31 : 1.618 ratio. But 9.2" from the edge gives an Feq hump at 280hz, then its response drops like a rock. Don't forget that a driver on an open baffle rolls like an infinite baffle. It hits its mass corner (Fs/qts) then rolls off............. Qts .2 lowther with fs of 50hz, the driver will roll off below 250hz regardless if the baffle is 8' wide.
The larger baffle you get, the lower you go (unequalized and not including mass corner), but the less back wall bounce (assuming baffle is 5' from the back wall so you get best sound). Some say huge open baffles have a black hole in the middle (no 10ms low level wall bounce fill).
Or make a foam box to surround the back of the driver and place the open baffle much closer to the front wall. You get clean mids that an OB give you and you can have it a foot from the wall.
Norman
One problem with a passive crossover in a system like this is that the calculated design may be far from what sounds best.
As far as active:
Scenario 1 : A $250 digital crossover is plunked down in the analog signal. The device must encode and then later decode the signal. It has 3 A/D converters and 6 D/A converters (for $250). It can't be surprising there's a loss in quality.
Scenario 2: The Crossover as DAC. $800 - $2000. The crossover is the last stop in the digital chain. You make sure the computer/transport data rate do not require a conversion. The A/D converter isn't used. This sounds a lot better. Because it's not just a crossover, It's a DAC, EQ, and xover.
Most people wouldn't bother with an active on a two way system. But a passive on this system is unlikely to be near optimal.
As far as the design, it's worth noting how Linkwitz got a pretty high WAF for the Orion. He used 2 10" high xmax stacked woofers to move air. He integrated the top and bottom. Most O.B. designs low WAF is only "bettered" by bass horns.
As far as active:
Scenario 1 : A $250 digital crossover is plunked down in the analog signal. The device must encode and then later decode the signal. It has 3 A/D converters and 6 D/A converters (for $250). It can't be surprising there's a loss in quality.
Scenario 2: The Crossover as DAC. $800 - $2000. The crossover is the last stop in the digital chain. You make sure the computer/transport data rate do not require a conversion. The A/D converter isn't used. This sounds a lot better. Because it's not just a crossover, It's a DAC, EQ, and xover.
Most people wouldn't bother with an active on a two way system. But a passive on this system is unlikely to be near optimal.
As far as the design, it's worth noting how Linkwitz got a pretty high WAF for the Orion. He used 2 10" high xmax stacked woofers to move air. He integrated the top and bottom. Most O.B. designs low WAF is only "bettered" by bass horns.
I pretty much disagree with everything you have said.
A passive crossover design can work great on a two way OB system, there are even some advantages to using a passive crossover. Designing one is not that hard.
I have also found that a pro digital crossover can sound just fine. I have not had any problems or noticed any degradation with my active digital crossover. I think using the balanced connectors and not trying to convert from RCA jacks to a balanced connector helps. The pro digital crossover allows you to try all different combinations of crossover frequencies, slopes, and levels of boost to dial in the best response. Knowing what works, the next step to an equivalent passive crossover is not that complex.
A passive crossover design can work great on a two way OB system, there are even some advantages to using a passive crossover. Designing one is not that hard.
I have also found that a pro digital crossover can sound just fine. I have not had any problems or noticed any degradation with my active digital crossover. I think using the balanced connectors and not trying to convert from RCA jacks to a balanced connector helps. The pro digital crossover allows you to try all different combinations of crossover frequencies, slopes, and levels of boost to dial in the best response. Knowing what works, the next step to an equivalent passive crossover is not that complex.
MJK said:
Maybe I wasn't clear. I think the pro crossovers are fine. But if you put an inexpensive Behringer after a good DAC it's not going to sound as good as it would with the DAC and a passive crossover.
The opinions of the Behringer are so varied it seems to me some people must be placing it after the DAC.
I have a modified Behringer and it's fine. I've also heard a friends dbx, and that was good too. I would have gone with the dbx to avoid the Behringer mods, but it's only 24/48. I've purchased a fair amount of 24/96 classical music.
Your final point about using the active to find out how you want to build a passive is good.
I've only built a simple passive xover. I much rather play with the sound on an active.
I'll add that when a passive is used and sounds good, the project is usually finished. The potential of other possible setups is not explored. I think the math is only a rough model that will usually be O.K.
Re: Re: Open Baffle: long-term S.Q., what's your experience?
Wow, thanks guys for all the input.
I guess the quirk I'm thinking of isn't necessarily a frequency response issue, but just that the bass on a pure OB is often described as loose and kind of soft. I suppose that this is one of the trade-offs for getting such a natural midrange response; being rid of the box and all.
I would think that one would solve this with some sort of woofer or sub in conjunction with the midrange driver on the OB, but in the case of the Lowther I've heard it's difficult to mate it with a sub because the Lowther is so much quicker and more responsive than most subs. Any ideas on a good match?
I like the idea of using the Lowther, too, but for the issue of sub integration. It seems that the Lowther alone on an OB would essentially have no bass foundation to speak of, as Norman points out.
Originally, I was thinking a good first stab was to try the Altec 755E on some very simple but bulkish OB's, a la the plans that Joseph Esmilla suggests on his website. I think Art Dudley did something similar in Stereophile with a pair of Altec 755Cs with good results. Anyone have any building a big OB with plexiglass or the like? That would make the speaker look much less bulky if it sounds alright. I recall Thorsten Loesch (I think) did something like this several years ago. Has anyone tried it?
Ideally, there exists a good inexpensive sub solution that integrates well with the speed of the Lowther. Then I could see setting up a OB speaker solution with a smaller baffle for the DX-3's above, and a sub in the base below. That would have a much greater WAF. A super tweeter maybe, too, if needed. One of the issues in such a case is to design a crossover solution that doesn't muddy up the Lowther's full-range driver purity; I need to do more research on this.
I can't remember specifically, but didn't Dick Olsher make something like this with a Lowther driver called the Basszilla?
Initially, I was very interested in exploring Orion type designs, especially ones with the dipole woofer, but as I explored it further, it seemed a little too involved with the electronics and multi-amping. Maybe for another day.
Anyhow, I'm not a bass freak or anything, just that the Klipsch I use (modded Heresies and Synergy F3s) are more fulfilling on a wider range of music as they have a more even frequency distribution.
Thanks for the input. I'll read through the thread a little closer to glean more insight from your thoughts.
I take it that a lot you you are, indeed, very satisfied with your OB solutions.
Thanks,
KT
MJK said:
Wow, thanks guys for all the input.
I guess the quirk I'm thinking of isn't necessarily a frequency response issue, but just that the bass on a pure OB is often described as loose and kind of soft. I suppose that this is one of the trade-offs for getting such a natural midrange response; being rid of the box and all.
I would think that one would solve this with some sort of woofer or sub in conjunction with the midrange driver on the OB, but in the case of the Lowther I've heard it's difficult to mate it with a sub because the Lowther is so much quicker and more responsive than most subs. Any ideas on a good match?
I like the idea of using the Lowther, too, but for the issue of sub integration. It seems that the Lowther alone on an OB would essentially have no bass foundation to speak of, as Norman points out.
Originally, I was thinking a good first stab was to try the Altec 755E on some very simple but bulkish OB's, a la the plans that Joseph Esmilla suggests on his website. I think Art Dudley did something similar in Stereophile with a pair of Altec 755Cs with good results. Anyone have any building a big OB with plexiglass or the like? That would make the speaker look much less bulky if it sounds alright. I recall Thorsten Loesch (I think) did something like this several years ago. Has anyone tried it?
Ideally, there exists a good inexpensive sub solution that integrates well with the speed of the Lowther. Then I could see setting up a OB speaker solution with a smaller baffle for the DX-3's above, and a sub in the base below. That would have a much greater WAF. A super tweeter maybe, too, if needed. One of the issues in such a case is to design a crossover solution that doesn't muddy up the Lowther's full-range driver purity; I need to do more research on this.
I can't remember specifically, but didn't Dick Olsher make something like this with a Lowther driver called the Basszilla?
Initially, I was very interested in exploring Orion type designs, especially ones with the dipole woofer, but as I explored it further, it seemed a little too involved with the electronics and multi-amping. Maybe for another day.
Anyhow, I'm not a bass freak or anything, just that the Klipsch I use (modded Heresies and Synergy F3s) are more fulfilling on a wider range of music as they have a more even frequency distribution.
Thanks for the input. I'll read through the thread a little closer to glean more insight from your thoughts.
I take it that a lot you you are, indeed, very satisfied with your OB solutions.
Thanks,
KT
Re: Re: Re: Open Baffle: long-term S.Q., what's your experience?
I have not experienced loose or soft bass. Getting bass down to 40 Hz is not too hard, going down to 20 to 30 Hz can be done with a H or U frame. Bass quality is very good.
I ran a Lowther OB system for a few years with great results. It was big! You can read about it on my webiste under the Projects page. Since then I have revisited the design and proposed a smaller version on the AudioCircle website. At some point I want to build this newer version.
http://www.audiocircle.com/circles/index.php?topic=58469.0
I had no problem with bass drivers mating with a Lowther. Not everythig will work. My design worked well by using two Eminence Alpha 15A pro woofers and an active crossover. I don't see why the newer design would not also work well with the same woofers and a passive crossover.
Yes, OB works well for me.
KT said:
I have not experienced loose or soft bass. Getting bass down to 40 Hz is not too hard, going down to 20 to 30 Hz can be done with a H or U frame. Bass quality is very good.
I ran a Lowther OB system for a few years with great results. It was big! You can read about it on my webiste under the Projects page. Since then I have revisited the design and proposed a smaller version on the AudioCircle website. At some point I want to build this newer version.
http://www.audiocircle.com/circles/index.php?topic=58469.0
I had no problem with bass drivers mating with a Lowther. Not everythig will work. My design worked well by using two Eminence Alpha 15A pro woofers and an active crossover. I don't see why the newer design would not also work well with the same woofers and a passive crossover.
Yes, OB works well for me.
Telstar said:
Allow me to refer you to Martin's paper...
http://www.quarter-wave.com/OBs/OB_Design.pdf
Rgds
marec said:
OK, so it was a pretty "standard" design. You did some comparisons with other OB projects?
I'm trying to find a wideband driver to use with just some bass support (active sub, cut very low 100-150hz max) and what's more important to run without a filter.
I was considering this Fostex, the FE166E, and Jordan drivers.
What's your opinion?
Hi KT
Just a note on the bass quality, whilst it is true many OBs will lack solid bass, it is not normally mushy or in any way indistinct, but rather much more musical, avoiding that one note type bass so typical of many box speakers.
Bass can indeed in the right sized room be incredibly powerful and beautifully articulated, but it should be noted that the bass will appear weak to the sides of the speakers and when outside the optimum listening position. Which can be a good thing if your not trying to keep everyone in the house awake while you listen.
Volume levels attainable can run from moderate through to immense, depending on design and drivers used, as an example my current set-up probably runs at close to 99db per watt, the main drivers are PAudios and they hit the dynamics like nothing else I have ever built or heard.
In my opinion OBs are the best solution when you want to hear the music in a way that gets close to the actual performance and you are prepared to sit and immerse yourself, if you just want to fill a room with sound then they are likely not the way to go.
Overall I feel once people have listened to OBs for any reasonable period of time, they basically don't want to listen to anything else, they just come to the conclusion that box speakers make a sound that is just hopelessly coloured and so Hi-fi like, if you know what I mean.
Definitely a taste worth acquiring, but truthfully, they require a bit of effort to get working well.
You may have gathered I am an OB fan, and I can't see that changing anytime soon, ask around a few forums and I am sure you get all the info you need to obtain OB nirvana
BTW MJKs posts are probably the most enlightening out there and you really should check the info on his site, very helpful.
Just a note on the bass quality, whilst it is true many OBs will lack solid bass, it is not normally mushy or in any way indistinct, but rather much more musical, avoiding that one note type bass so typical of many box speakers.
Bass can indeed in the right sized room be incredibly powerful and beautifully articulated, but it should be noted that the bass will appear weak to the sides of the speakers and when outside the optimum listening position. Which can be a good thing if your not trying to keep everyone in the house awake while you listen.
Volume levels attainable can run from moderate through to immense, depending on design and drivers used, as an example my current set-up probably runs at close to 99db per watt, the main drivers are PAudios and they hit the dynamics like nothing else I have ever built or heard.
In my opinion OBs are the best solution when you want to hear the music in a way that gets close to the actual performance and you are prepared to sit and immerse yourself, if you just want to fill a room with sound then they are likely not the way to go.
Overall I feel once people have listened to OBs for any reasonable period of time, they basically don't want to listen to anything else, they just come to the conclusion that box speakers make a sound that is just hopelessly coloured and so Hi-fi like, if you know what I mean.
Definitely a taste worth acquiring, but truthfully, they require a bit of effort to get working well.
You may have gathered I am an OB fan, and I can't see that changing anytime soon, ask around a few forums and I am sure you get all the info you need to obtain OB nirvana
BTW MJKs posts are probably the most enlightening out there and you really should check the info on his site, very helpful.
The emerald physics design seems to be good and inexpensive, if you willing to use an active xover.
I have a bass design question I hope some of you have tried. What about two identical bass (woofer) baffles back-to-back, with the rear firing unit 180 out of phase. What happens if the rear of the units are attached, and the phase is adjusted to produce minimum vibration?
I have a bass design question I hope some of you have tried. What about two identical bass (woofer) baffles back-to-back, with the rear firing unit 180 out of phase. What happens if the rear of the units are attached, and the phase is adjusted to produce minimum vibration?
I'll check this Wharfedale driver thanx
They were both crossed or only the Alpha 15a?
I can adjust that. I'll get a sub that should go as high as 200hz for high pass. Of course the sub will be OB too, with 1-2 alphas or 2 Peerless 12", U shape.
There is also a program in german. I sent you an email.
The FE166E is Nelson pass favourite of the cheap fostexes, and the response looks better than the 108EZ. A pretty narrow baffle should make it roll at around 200hz. I can use EDGE
I plan to put two speakers in series if needed, but no filter. I can do some digital EQ in the computer source, though, but at later date. I want the system to perform decent without EQ.
Sorry, I think I misunderstood. If you are not starting from an existing production sub, but want to use a high QTS driver in an open baffle, please use MJKs designs. They will save you so much experimentation. Having established a baseline, then you can go on to perfection...
Use lowthers offset in a 48x 20 baffle, put two cheap 15As each side, use a cheap ultradrive x-over and find the music....
Rgds
Use lowthers offset in a 48x 20 baffle, put two cheap 15As each side, use a cheap ultradrive x-over and find the music....
Rgds
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