I had two major problems with his statements, vagueness not withstanding.
This is absolute nonsense. OB bass is not "wrong". Open baffle bass is the cleanest, clearest and most natural bass that current speaker technology can produce. POORLY implemented OB is wrong. Just like poorly implemented anything. Open baffles only "weakness" is that for (very) high SPL @ very low frequencies - you need large drivers capable of very large excursions. And large excursions means more distortion. So what? If you need high SPL @ 20hz - which means NOT most music, mainly HT or maybe pipe organ, etc. ,then you have two choices. Multiple large low distortion drivers in a deep H or U frame - however many is needed to keep excursions reasonable to avoid your distortion threshold/SPL needs. Or - just as SL point's out (and I do!) , use a sealed woofer system to produce bass below 40hz to relieve the OB's of large excursions, or just reduce the number of drivers/size enclosure needed. Open baffle down to 40hz. Two boxes back to back as you vaguely suggested is still TWO BOXES. With ALL the problems associated with boxes. Re-radiation of sound through the cones. Release of stored energy from the enclosure. Why no mention of this Magnetar?
The second issue - the one that prompted me off the sideline after reading most of the thread with amusement - was this.
That might be news to anyone who has actually heard an Orion. A speaker known and MEASURED for low distortion across its entire range of operation. It is NOT intended to produce 120db @ 20hz. The designer is absolutely clear on this. Its just another very foolish statement. If you don't like the clarity and naturalness of the bass from a boxless speaker, then fine. Enjoy your 120db @ 20hz "box" sound. But claim that open baffle is "wrong" and SL - who knows more about loudspeaker design than you will in your lifetime - designed a "distortion box"..well, you saw my previous response. You need not bash a superior design to promote the attributes (however vague) of your own. Let your design stand on its own merit.
Cheers (bedtime)
AJ
- Magnetar.
This is absolute nonsense. OB bass is not "wrong". Open baffle bass is the cleanest, clearest and most natural bass that current speaker technology can produce. POORLY implemented OB is wrong. Just like poorly implemented anything. Open baffles only "weakness" is that for (very) high SPL @ very low frequencies - you need large drivers capable of very large excursions. And large excursions means more distortion. So what? If you need high SPL @ 20hz - which means NOT most music, mainly HT or maybe pipe organ, etc. ,then you have two choices. Multiple large low distortion drivers in a deep H or U frame - however many is needed to keep excursions reasonable to avoid your distortion threshold/SPL needs. Or - just as SL point's out (and I do!) , use a sealed woofer system to produce bass below 40hz to relieve the OB's of large excursions, or just reduce the number of drivers/size enclosure needed. Open baffle down to 40hz. Two boxes back to back as you vaguely suggested is still TWO BOXES. With ALL the problems associated with boxes. Re-radiation of sound through the cones. Release of stored energy from the enclosure. Why no mention of this Magnetar?
The second issue - the one that prompted me off the sideline after reading most of the thread with amusement - was this.
- Magnetar
That might be news to anyone who has actually heard an Orion. A speaker known and MEASURED for low distortion across its entire range of operation. It is NOT intended to produce 120db @ 20hz. The designer is absolutely clear on this. Its just another very foolish statement. If you don't like the clarity and naturalness of the bass from a boxless speaker, then fine. Enjoy your 120db @ 20hz "box" sound. But claim that open baffle is "wrong" and SL - who knows more about loudspeaker design than you will in your lifetime - designed a "distortion box"..well, you saw my previous response. You need not bash a superior design to promote the attributes (however vague) of your own. Let your design stand on its own merit.
Cheers (bedtime)
AJ
That was my point. It's all very well to say to people try this or that, but in this case, unless you have a choice of drivers, it's not really practical! 😉
I'm no speaker expert by a log way but I do know what I like and the sound of dipole (open-baffle) compared to a boxed system is far more preferable, even at lower frequencies. Of course, I don't want distortion but then again I'm old enough and wise enough (I hope) not to push any design beyond its limits. 😉
Magnetar said:
(JPK) Well, that's just not a dipole. I do something similar with my CRAW design which uses two woofers in separate chambers. When set up as a cardioid, the level of the rear driver can be adjusted so that the null behind the system occurs at a specific distance. However, this has a significant effect on the on axis response as well, and isn't a true cardioid. See http://www.musicanddesign.com/craw.html about 1/2 way down the page. As soon as the front and rear responses have different amplitude and the phase difference is other than 180 degrees you have something other than a dipole and it may well perform better than a dipole in a given room. A dipole, for example, has no room gain. A true cardioid on the other hand has room gain similar to a sealed box system. So it is quite understandable why your system would perform differently than a OB dipole, or any configuration of a dipole, H, W, two identical sealed box system separated by d and 180 out of phase; it's not a dipole. And if you find your setup to perform better than a dipole in your room that is an equally legitimate evaluation.
This is just your opinion - and my experiance with linkwitz OB bass tells me it can be bettered in several ways - 1) a well designed/integrated horn sytem, 2) a well designed/implemented Karlson Koupler, 3) this current apparatus ( I believe I have been corrected above - it's a "quasi-dipole/ quasi-cardiod") integrated properly. Try M&k, Meyers, Legacy, Wisdom Audio, ect........
Have you built a good bass horn? Have you built a good Karlson Koupler? Have you built a quasi/dipole/cardiod? I have loaded linkwitz boxes with superior drivers (15" JBL 2235's) and they did not 'work' for me. If it does not work to my satisfaction it is wrong.
Energy released through the box? One bass cabinet is almost 5" thick and braced, the other operates with another driver in push pull and is sand filled.
20 Hz or deep bass? Well I use three horns (and three channels!) for that as seen in these pictures - the linkwitz boxes are toys in the bottom octaves compared to this - LOL
Have you built a good bass horn? Have you built a good Karlson Koupler? Have you built a quasi/dipole/cardiod? I have loaded linkwitz boxes with superior drivers (15" JBL 2235's) and they did not 'work' for me. If it does not work to my satisfaction it is wrong.
Energy released through the box? One bass cabinet is almost 5" thick and braced, the other operates with another driver in push pull and is sand filled.
20 Hz or deep bass? Well I use three horns (and three channels!) for that as seen in these pictures - the linkwitz boxes are toys in the bottom octaves compared to this - LOL
AJinFLA said:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
ScottG said:
True (arrogance) - replies - I hate to type -
thanks for the correction on labeling what I'm listening to Scott.
johninCR said:
I have no intention of doing anything but trying to improve my playback. I doubt anyone will ever build what I build cause it's often huge and ugly - so why bother explaining it? Besides I'm no engineer, just like to play with this stuff.
-------BTW, I'm on your side vs the dipole purists, I prefer some attentuation of the rear wave. It seems to make placement much more flexible with no ill effects. I hope you hang around to pick your brain with a few questions.
I'm no purist with anything - whatever works for me (not much cause I am picky) is fine.
-----1. I have to assume that in your dipole (hybrid) mode that you have room modes under control. How much bass to you have at the sides of your speakers? I guess my real question is how much can you fudge that pure dipole null at the sides and still keep ceiling and side wall modes under control?
These speakers are pure dipoles (I guess) from like 200 cycles up - I can stand between them and the level goes way down - they are almost touching the side walls. I also have a 'quasi-dipole' center channel
------2. I've planned to go the W baffle route with lots of drivers, since my target is OB down close to 28hz where my remaining room mode comes into play. I've often thought of using stuffing in the rear openings as a way to dial in more bass with a W baffle, resulting in comething somewhere between Aperiodic and dipole. Did you ever play around with that? If not, do you think it makes sense?
Yes - I do this with the Heils, I also use 24" diameter bass traps directly behind the main speakers.
===3. Another thought to generate more low end with OB, is to use a big panel absorber (possibly a helmholtz absorber that can be tuned to specific frequency ranges) directly behind by OB's. The idea is to absorb as much of the rear wave hitting the wall as possible. The ceiling and side nulls would remain pretty much intact, but whatever gets absorbed in back has to equate to more net output in the front. I would get the added benefit of a bass trap to help address my one remaining room mode. Does that idea hold water at all ?
Yes it does - see above
---4. For an HT sub to be used below 28hz use a very low tuned ported sub near the rear wall wired out of phase, then a similarly tuned sub 12ft closer and very near the listening position in the form of a coffee table. I come up with an Fequal of 16hz, plus at 1m distance vs over 4 meters the coffee table sub will be about 12db louder at the seating position. This should give me tremendous seating area bass, but a drastic reduction of what leaves the room. I can also play around with some stuffing in the vents for fine tuning. As long as I keep my low pass quite low and all output is below my lowest room mode, it seems like a great idea. Is there some problem that I'm not considering ?
Great ideas - Just make sure you fire the bass toward the floor or into the back of your chair and really brace the cabinets so you get no rattles- I have a friend that I built a push pull dipole (quasi he uses the Pardigm X30 with phase adjustment for the back woofers too) four woofer (JBL 2235H 15's) woofer sub for and it fires into the back of his couch. It will rattle your teeth with precision.
😀
Nuuk said:
I am confused too? How can we go build one and report back if we do not know what exactly to build? Or build something and report back with inaccurate results because we have built something totally different.. rather than what he has in mind?
May be his tune boxes are bass reflect boxes and the front facing box is a sealed box?
Attachments
Magnetar said:
Please send me a PM with it as attachments. It should not take too long for me to download it. Thanks...
chris ma said:
Butcher? Those look sweet!
My daughter has the digital camera and is out of town for the weekend - I'll snap the speakers when she returns.
Been out of reach for a weekend and in my wildest dreams i didn't think that this thread will have 6 pages 
It's a great discusion and I must say that now I began to worry about building OB speakers. Not just because Magnetar has put some extensive research results on this forum, but because I can't get good pro drivers here in my country for OB. Summing up, I ended with closed box with equalisation, where I can get 30Hz@95dB what is exactly what I need. Many of you might say "go open baffle", but the truth is, that I haven't ever heard OB speakers and I don't know if I will like the sound. It was just a thought to go OB, but many problems arised since that.
Thanks all for your words.
I'll be checking this thread longer - can't wait to see Magnetar's speaker experiments
It's a great discusion and I must say that now I began to worry about building OB speakers. Not just because Magnetar has put some extensive research results on this forum, but because I can't get good pro drivers here in my country for OB. Summing up, I ended with closed box with equalisation, where I can get 30Hz@95dB what is exactly what I need. Many of you might say "go open baffle", but the truth is, that I haven't ever heard OB speakers and I don't know if I will like the sound. It was just a thought to go OB, but many problems arised since that.
Thanks all for your words.
I'll be checking this thread longer - can't wait to see Magnetar's speaker experiments
DarkOne,
I hope you at least decided against the double Beyma idea. It's just such a waste of the potential of the Beymas to try to force bass out of them. You said you don't listen loud, so I guarantee 1 will go more than loud enough for you as long as you don't ask it to play deep bass. Forcing the bass is asking for problems including distortion and is exactly the kind of thing that Magnetar stays away from with his approach. It's like putting a bulldozer transmission in a high performance sportscar just to make it able to climb a very steep hill, you'll lose all the performance for which it was designed.
I hope you at least decided against the double Beyma idea. It's just such a waste of the potential of the Beymas to try to force bass out of them. You said you don't listen loud, so I guarantee 1 will go more than loud enough for you as long as you don't ask it to play deep bass. Forcing the bass is asking for problems including distortion and is exactly the kind of thing that Magnetar stays away from with his approach. It's like putting a bulldozer transmission in a high performance sportscar just to make it able to climb a very steep hill, you'll lose all the performance for which it was designed.
A competent designer will choose the appropriate drivers BEFORE he/she designs and based on the design goals. Scientific principles - mathematics/physics/psychoacoustics(design programs,measurements, test data, etc)will guide the designer to success. Failure will be due to the designer, not the design. An INCOMPETENT designer will cobble something together based on ignorance instead of science, then, upon failure - blame the design. Sound familar?
I've heard good sounding 2 way passive box speakers - and bad line array ribbon open baffle/horns.
It doesn't matter whether is sealed,ported,horns, open baffle, ribbons, whatever. It (sucess/failure) still will ALWAYS come down to the designer. It's really just that simple.
Cheers,
AJ
I've heard good sounding 2 way passive box speakers - and bad line array ribbon open baffle/horns.
It doesn't matter whether is sealed,ported,horns, open baffle, ribbons, whatever. It (sucess/failure) still will ALWAYS come down to the designer. It's really just that simple.
Cheers,
AJ
Much ado about nuthin ...
I come back to this thread after a day and the fog seems to clear up:
Following his recent explanations magnetar simply has constructed some dipole/cardoid variations that work in his room and might be overwhelming for sure - taking magnetars usual material overkill in regard. There seems to be nothing specially new or mystical about it - all following the theoretical lines Linkwitz and especially John K. have layed out before.
What gives me a bad taste is the big mouth, with which magnetar tried to bash Linkwitz and his followers. People like him, who stand on the shoulders of bigger men, should not try to bang away at their supporters - one might take a plunge too deep.
PS: Since I am working in advertising: I am amazed at magnetars ability to cause a really big stir by just making same blatant statements in the right place. My compliment for that!
Greets
Rudolf
I come back to this thread after a day and the fog seems to clear up:
Following his recent explanations magnetar simply has constructed some dipole/cardoid variations that work in his room and might be overwhelming for sure - taking magnetars usual material overkill in regard. There seems to be nothing specially new or mystical about it - all following the theoretical lines Linkwitz and especially John K. have layed out before.
What gives me a bad taste is the big mouth, with which magnetar tried to bash Linkwitz and his followers. People like him, who stand on the shoulders of bigger men, should not try to bang away at their supporters - one might take a plunge too deep.
PS: Since I am working in advertising: I am amazed at magnetars ability to cause a really big stir by just making same blatant statements in the right place. My compliment for that!
Greets
Rudolf
johninCR said:
Yes, I'd like to use 2 beymas 10g40 in MTM configuration. Not sure what tweeter I'll use, but maybe theyr T2030 for first test and I'll see. Previously mentioned FAB Audio uses these drivers with succes, so why not use the same drivers.
I must say that my first idea was to use only one woofer, but when I saw I would easily get Xmax of these driver. But here in slovakia is one company www.acon.sk , which forces their studio monitors with 8inch woofer to 104dB SPL while freq response is down 3dB in 30Hz-20kHz (AND THEY SOUND VERY GOOD). So maybe I'll try one woofer and less equalisation.
Time will show if I go the right way.
DarkOne,
You're missing my point. 1 Beyma plus an appropriate woofer. If you only ask it to go down to 80hz or so, then use the subwoofer control on the Behringer to control the bottom end, or keep your speakers a small 2 way and have a woofer or two in a separate enclosure as a sub. Beyma's measured BR enclosure tuned to 45hz shows it to be -3db at 80hz, so IMO asking for flat to 40hz from those drivers is asking too much whether or not some box program is telling you it's possible. Possible doesn't tell you how it will sound. At 40hz you are operating half an octave below the Fs of the drivers where distortion increases drastically. You're also pushing the drivers to their excursion limit even at low listening levels which again is begging for distortion. Adding a second Beyma 10G40 to each side for over $200/ea will help very little and isn't the right answer. Using something else to fill in below 100hz will get you much better results and save money. You'll end up with less distortion, deeper extension, much higher potential output, and money in your pocket. 30hz to 80-100hz is easy if you're not going dipole, just not for that driver.
You're missing my point. 1 Beyma plus an appropriate woofer. If you only ask it to go down to 80hz or so, then use the subwoofer control on the Behringer to control the bottom end, or keep your speakers a small 2 way and have a woofer or two in a separate enclosure as a sub. Beyma's measured BR enclosure tuned to 45hz shows it to be -3db at 80hz, so IMO asking for flat to 40hz from those drivers is asking too much whether or not some box program is telling you it's possible. Possible doesn't tell you how it will sound. At 40hz you are operating half an octave below the Fs of the drivers where distortion increases drastically. You're also pushing the drivers to their excursion limit even at low listening levels which again is begging for distortion. Adding a second Beyma 10G40 to each side for over $200/ea will help very little and isn't the right answer. Using something else to fill in below 100hz will get you much better results and save money. You'll end up with less distortion, deeper extension, much higher potential output, and money in your pocket. 30hz to 80-100hz is easy if you're not going dipole, just not for that driver.
If you are wondering what dipoles sound like, find a pair of inexpensive 4" full range drivers and mount them on a flat or shallow U baffle.
I used the Phoenix baffle dimensions of .5m by .3 m with 75 mm wings (18" by 12" by 3') and mounted the $.49 NSB drivers.
I didn't know what to expect.
That test made my mind to build a larger project. 🙂
I still smile every time I listen.
If I were to do it again, I would mount them on a 3' by 2' (.7m by.5m) flat baffle slightly off center, with the baffle resting on the floor.
I understand that those are not necessarily available where you live. Any inexpensive "wide range" driver should do for "proof of concept" testing.
Good Luck.
Doug
DougL said:
Maybe, I'll search local shops if they have some inexpesive fullrange drivers. If I can find one, I'll try it. I like Beymas because of their high sensitivity (my amp is class AB 150W, but it can be easily configured to single ended class a 20W, what I like the most). The idea of no box is good for me because I have no woodworking skills, that was the only reason why I wanted open baffle speakers.
I'll try it.
Thanks
You can get the beyma's and decide later on the alignment for them. Before building a box, mount one on a piece of plywood. Play that on one channel and your existing box speaker on the other channel. Understand the bass will be pretty thin, but it will give you a good idea of the OB sound and more than likely you won't ever put them in a box. You may even be able to cannibalize what you already have to fill in the bass at least while you figure out what to do long-term.
Have fun!!!
Have fun!!!
- Status
- Not open for further replies.